Mixed Prairie - I

The ultimate reference for mixed prairie (and shortgrass prairie) from standpoint of descriptions of range vegetation and response to disturbance is--and will likely always be--the classic Grasslands of the Great Plains by Weaver and Albertson (1956). Definitive source of knowledge regarding mixed paririe from an ecosystem perspective is that of Coupland (in Coupland, 1992, ps. 151-182). The comprehensive monograph on shortgrass plains (=prairie, steppe) edited by Lauenroth and Burke (2008) overlapped--by necessity--parts of the mixed prairie so as to be a valuable reference for western extremities of mixed prairie.

6. Mixed prairie-mesquite savanna- Mixed prairie of blue grama, sand dropseed, sideoats grama, galleta, buffalograss, curly mesquite, and little bluestem with a relative abundance of honey mesquite such as to form a grass-shrub savannah. The species composition and physiogonomy of this range plant community was interpreted by the author as representing an example of vegetation similar to the rangeland cover type described by the Society for Range Management (Shiflet, 1994) as Mesquite-Grama (SRM 718) and as a representation of the potential natural vegetation mapped by Kuchler (1966) as a gramagrass-buffalograss-mesquite community (one of the units designated as Grassland and Forest Combinations).

The relative density and cover of honey mesquite (Prosopis glandulosa) on the virgin grasslands prior to the heavy hand of the white man as a stock-raiser, teamster, farmer, oilman, road-builder, etc. will remain "known but to God". There will always be arguments as to the extent and ecological role of this native legume on the natural grasslands, shrublands, and savannas within the biological range of mesquite. Even use of terms like grasslands and savannas reflects biases (including those based on sound, well-conducted research) because such designations of vegetation indicate assumptions about relative absence of mesquite (on grasslands), limited presence of mesquite (savanna), or presence of mesquite as a dominant or at least influencial species (on shrublands or even forests).

Accounts by such diverse frontiersmen as buffalo runners, freighters, soldiers, and pioneer cattlemen made it quite clear that the Southern Great Plains had relatively little mesquite (at least that of such size, density, and cover as to be obvious) except in isolated groves, along watercourses, on breaks sites, etc. Buffalo chips not mesquite wood was the more usual fuel source on the vast southern grasslands of the interior of semiarid North America. However as soon as farmers began to break the virgin sod-- and break plow shares and tongues on big mesquite lignotubers beneath the soil surface-- it became apparent that there had been more mesquite than was realized. Fires set by lightening and Indians had kept mesquite shoots burnt back to inconspicuous size. Perhaps browsing by such native herbivores as buffalo, elk, or even rodents and lagomorphs had been a factor that maintained mesquite and other woody range plants at lower population levels and in subordinant (vs. dominant) ecological roles. The "pet" theory among the first cattle-raisers as to the most important animals feeding on mesquite (and thereby keeping mesquite in check) was the prairie dog. Old-time cowmen made the connection in their observations between prairie dog eradication programs ("poisoning champaigns") and mesquite invasion.

That there has been a great increase in density and cover of mesquite across rangelands of southwestern North America is beyond doubt or debate, but the degree and origin or cause of this increase is widely debated, discussed, cussed, and published. Nobody half-way knowledgable of the subject can argue against some role of overgrazing, cessation of fires (both atmospheric and anthropogenic in origin), farming, oil and gas development, commercial trade (as in trail- road-building), and even some climatic changes. Perhaps the history of mesquite invasion from perspective of causes is unimportant in a practical sense except to use such knowledge to try to "stem the tide". But knowledge as to the relative "amounts" of mesquite in the various plant communities (range types) in pre-Columbian vegetation would be invaluable in establishing "base lines" or "benchmarks" from which contemporary resource managers like rangemen could measure departure from the potential natural vegetation. (It should be borne in mind, always, that the current potential natural vegetation may differ drastically from pre-white man potential natural vegetation, or for that matter, pre-red man.)

The relative emphasis on mesquite (and mesquite reduction) as a major problem (and goal) in management of brush-infested ranges (including those where mesquite is only one of many brush species) has varied over time with changes in market value of commodities and the latest academic fad and barrage of "buzz words". Emphasis and perception of the mesquite problem has swung widely from the optimistic utopia of mesquite eradication (destroy every last smidgen of it) to the equally naive-- and idiotic-- misconception that because some mesquite is valuable for deer habitat it ought to be increased on ranches that sell hunting leases. In between these mesquite-mood swings even the realistic professional goal of some degree of control of this noxious range plant has varied with changes in control costs, cattle and real estate markets, oil royalties, and rainfall.

How much mesquite should there be? The answer to that question will always vary from one pasture, one operation, one public park, etc. to the next as well as in conjuction with the factors just noted. How much mesquite was there? The answer to that question, which contemporary rangemen will never really know, also varied from one range site, one precipitation zone, one fire regimen, etc. to the next. It also depended on what point in time and the time span that the question referred to. Undoubtedly, relative abundance of mesquite varied over time scales that ranged from a few growing seasons to the end of one drought to start of the next drought to the longest period of a major climatic shift.

The relative proportion of honey mesquite on this mixed prairie was viewed by this author as being roughly the maximum amount of mesquite that could occur on climax mixed prairie (within the grassland or grass-shrub savanna based on pre-Columbian potential natural vegetation). Vegetation of the High Plains and Rolling Red Plains having mesquite populations greater than the general approximation represented by the plant community in this photograph would be in a state of retrogression according to the judgment of this author. Others might opt for substantially more mesquite and relatively less grass. They can place their photographs and state their conclusions on their web sites. This author stands by the traditional conclusion that honey mesquite is, though a native species, an ecological invader on many (in Texas, most) grasslands and savannas and that control of this noxious species is one of the major challenges to sound range management.

Honey mesquite is one of the most important range brush species in North America (the most important statewide in Texas and parts of adjoining states). Stewardship of range resources demands that mesquite be attacked with the full arsenal of current science and technology consistent with economic feasibility. And go at it "with a vegeance"!

In the context of range cover types and use of climax vegetation as a benchmark with which to measure management it will be recalled here that departure from climax is neither proper nor improper management until specific objectives-- based on ecological as well as economic principles-- are established.

Chaves County, New Mexico. June (and a dry one). FRES No.38 (Plains Grasslands Ecosystem). K-76 (Mesquite-Buffalograss; Bouteloua, Buchloe, Prosopis). SRM 718 (Mesquite-Grama). (The example of vegetation in this photograph grew west of where K-76 was mapped. It was interpreted as an "island" of the larger mapping unit, such smaller outliers of the larger mapping scale not having been delineated by Kuchler.) Mixed "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Conchas/Pecos Plains Ecoregion, 26n (Omernik and Griffith, 2006).

7. Mixed prairie-mesquite savanna in Texas Rolling Red Plains- This was a good example of the now nearly ubiquitous mesquite mid-grass range of the south-eastern portion of the Great Plains region. The original mixed prairie, a climax grassland type of tallgrass, mid-grass, and short grass layers, has become degraded (for whatever combination of reasons and factors) by woody plant invasions accompanied by nearly complete loss of the tallgrass element and a mid-grass layer comprised mostly of increasers and invaders. In this example sideoats grama, the climax dominant for this cover type, was reduced and largely replaced by threeawns, most notably Wright's threeawn (Aristida wrightii= A. purpurea var. wrightii). Other major mid-grasses included silver bluestem and sand dropseed. Hairy grama was locally dominant growing to dimensions and densities more typical of a mid-grass such as sideoats grama. There were distinct "patches" (microsites) of shortgrasses of buffalograss and blue grama (in that order). One such "patch" was visible in front and to left of the honey mesquite.

Rolling Red Plains of the Great Plains physiographic province.

Pitchfork Ranch, Dickens County, Texas. Estival aspect. August. FRES No. 38 (Plains Grasslands Ecosystem). K-76 (Mesquite-Buffalograss; Bouteloua, Buchloe, Prosopis). SRM 718 (mesquite-grama cover type). Mixed "Short-Grass" Series of Brown et al. (1998). Mixedland range site. Southwestern Tablelands- Flat Tablelands and Valleys Ecoregion, 26b (Griffith et al., 2004).

8. Rough land mixed prairie-redberry juniper (Juniperus pinchotii) savanna- Across many acres of mixed prairie range redberry juniper takes the place of honey mesquite as the dominant woody invader. Occurrence of redberry juniper as the dominant invader tends to be on rangeland with more prominent dendritic drainage patterns (ie. "rough land") especially near breaks sites that, being less prone to fire, serve as reserviors for seed-producing woody plants. Redberry juniper is fire-adapted being one of the rare sprouting conifers.In this example, a range infested with redberry juniper had been treated by prescription burning seven growing seasons previously. Redberry juniper had resprouted plus some of the original junipers had been "passed over" by the prescribed fire.

Herbaceous vegetation consisted of both mid-grass and shortgrass layers. The major mid-grass species was sideoats grama. In places sideoats was dominant. Other mid-grasses included silver bluestem and sand dropseed. Hairy grama was often the local dominant and it appeared to have a role more like that of a mid-grass, especially sideoats grama. Buffalograss was the major short grass species. It was associated with blue grama that grew to size more that of a short grass. Soapweed (Yucca glauca) was an associate shrub species.

Great Plains phyiographic province; Rolling Red Plains component (east of Caprock escarpment).

Pitchfork Ranch, Dickens County, Texas. Estival aspect. August. FRES No. 38 (Plains Grasslands Ecosystem). K-76 (Mesquite-Buffalograss; Bouteloua, Buchloe, Prosopis). SRM 718 (mesquite-grama) or SRM 727 (mesquite-buffalograss). SRM designation was confusing. In protected areas sideoats grama was dominant which fit descriptions of both 718 and 727. This in conjuction with local dominance of hairy grama plus prescence of blue grama in shortgrass "patches" qualified this vegetation as SRM 718 (mesquite-grama). Conversely, presence of redberry juniper as the dominant woody plant fit the variant description of SRM 727 (mesquite-buffalograss) except that buffalograss was far from dominant. The reader can reach his own conclusion. Mixed "Short-Grass" Series of Brown et al. (1998). Mixedland range site. Southewestern Tablelands- Flat Tablelands and Valleys Ecoregion, 26b (Griffith et al., 2004).

9. Advance of the enemy- Mixed prairie with onset of redberry juniper invasion. This was part of the same pasture presented in the two immediately preceding photographs except that here brush was sparse. Woody invasion was underway nonetheless. Recurrent fire-- natural or prescribed-- would prevent or reduce onset on a further brush problem.

This vegetation consisted of two herbaceous layers: 1) mid-grass dominated by Wright's threeawn with sideoats grama the associate and silver bluestem and sand dropseed locally common and 2) short grass consisting of buffalograss and blue grama.

Pitchfork Ranch, Dickens County, Texas. Estival aspect. August. FRES No.31 (Plains Grassland Ecosystem). K-76 (Mesquite-Buffalograss; Bouteloua, Buchloe, Prosopis). SRM 718 or 727 (see explanation in preceding caption). Mixed "Short-Grass" Series of Brown et al. (1998). Mixedland range site. Southwestern Tablelands- Flat Tablelands and Valleys Ecoregion, 26b (Griffith et al., 2004).

10. Sward of mixed prairie with two herbaceous layers- The distinct mid-grass and short grass strata of a mixed prairie were shown in these two slide. No, this was not spot grazing (at least not in the current growing season). The "spot" with grass of lower height was comprised of buffalograss and blue grama whereas the larger "spot" consisted of Wright's threeawn, sideoats grama, silver bluestem, and sand dropseed. Presence of smaller, "stunted"-appearing individuals of threeawn in the "low plant spots" and presence of some-- though restricted in cover and density-- buffalograss and blue grama among the cespitose mid-grasses suggested that past (previous seasons) spot grazing may have contributed to occurrence of the "patches" dominated by short grass species. Localized heavier utilization was clearly not the only factor, however, as this plant community pattern has been seen frequently on areas protected from grazing (eg. on steep slopes and larger canyon faces of breaks sites). Besides, on this site blue grama is generally interpreted as a decreaser while buffalograss is classified as an increaser. Yet these two species grew side-by-side in this vegetation. It was likely that soil differences at microsite scale were also factors in this mosaic of short grass and mid-grass.

Pitchfork Ranch, Dickens County, Texas. Estival aspect. August. FRES No. 31 (Plains Grassland Ecosystem). K-76 (Mesquite-Buffalograss; Bouteloua, Buchloe, Prosopis). SRM 718 or 727 (see explanation two captions above). Mixed "Short-Grass" Series of Brown et al. (1998). Mixedland range site. Southwestern Tablelands- Flat Tablelands and Valleys Ecoregion, 26b (Griffith et al., 2004).

11. Honey mesquite as a nurse plant- The nurse plant phenomenon has been described in the literature and is textbook knowledge (eg. Barbour et al., 1999, ps.153-156). Nurse plant relationships have been interpreted as a form of commensalism, those interactions which are positive or beneficial for one species (the "nursee") and neutral (having no meaningful impact) on the other species (the "nurser", which is mesquite in this instance). Honey mesquite functions as a nurse plant to many plant species, likely to as many or more than any other plant on the ranges of North America. This is more so in the Rio Grande Plains grass-shrub savanna than on the mixed prairie grasslands like those of the Rolling Red Plains. Even on the latter, as shown here, mesquite "plays host" to several other shrub and tree species. In this Red Plains case sugar hackberry (Celtis laevigata), lotebush, and brownspine prickleypear (Opuntia phaeacantha) have come in under the shade and moderated microenvironment afforded by honey mesquite. The most important outcome of the mesquite nurse plant drama is that mesquite-infested ranges become multi-storied, mixed-species brush thickets with noxious plant control much more complicated thereby requiring more elaborate and expensive control methods and greatly decreasing the likelihood of grassland restoration.

Taylor County, Texas. October. FRES No. 38 (Plains Grassland Ecosystem). K-76 (Mesquite-Buffalograss; Bouteloua, Buchloe, Prosopis). SRM 718 (Mesquite-Grama) in advanced retrogression.

12. Mixed species brush invasion on Rolling Red Plains mixed prairie- This is an example of the nurse plant relationship carried to it's ultimate development: mature and reproducing honey mesquite forming both canopy and part of a middle woody understorey layer with young sugar hackberry and large lotebush comprising a second brush layer and brownspine prickleypear as the latest and lowest growing shrub starting to development into a third woody plant layer. All three (or more) brush layers are more dense and taller than (and taking light and water from) what is left of the mid- and shortgrass species.

It is difficult to find "middle ground" with mesquite on grassland or savanna. Honey mesquite is a natural "monopolist". It will gain effective total control over resources required for plant growth, and bring it's co-conspiring, resource-dominating, robber baron buddies right behind it. FRES No. 38 (Plains Grassland Ecosystem). K-76 (Mesqujite-Buffalogreass, Bouteloua, Buchloe, Prosopis). SRM 718 (Mesquite-Grama) in ultimate state of ecological deterioration.

13. Mixed prairie in the Kansas Red Hills- Physiography of the northern limit of the Rolling Redlands or Rolling Red Plains and the physiogonomy of mixed prairie. Mixed prairie is the climax vegetation of this physiographic unit of the Great Plains or, according to some, the Plains Border. Presented here is the north end of a physiographic sub-province that begins in Texas and extends northward through Oklahoma following what was termed the Break of the Plains. In the Texas and Oklahoma Panhandles this break is very prominent where the western edge of the Rolling Red Plains meets the Southern High Plains. The persistent mantle of the High Plains or Llano Estacado (Staked Plains) is known as the Caprock Escarpment. Immediately east of the Staked Plains, then, is a geologic/edaphic region known, again, as the Rolling Red Plains or, still yet another synonym, Redbeds Plains. In Kansas this has traditionally been called the Red Hills. The definitive physiographic reference remains Fenneman (1931, ps. 25-30; 1938, ps. 606, 617-620).

The Redbeds Plains region had (has) some of the best developed mixed prairie vegetation. Much-- probably most-- of this general range type was either destroyed by the plow or, in Texas and southern Oklahoma, converted to a mesquite (Prosopis glandulosa) shrubland disclimax by a combination of overgrazing, underburning, oil and gas development, perhaps even by faunal changes and climatic shifts, and God alone knows what else. As if that was not enough, most of the mixed prairie that escaped the plow and the brush is in some state of vegetational retrogression (ie. range deterioration), some more so than others.

The mixed prairie vegetation shown in this and the next two slides was in the Kansas Red Hills and was in high Fair to low Good range condition class. These three photographs were followed by four photographs of mixed prairie sward in Excellent range condition class, but this latter vegetation was in the Southern High Plains province immediately north of the Red Hills.

In the present slide vegetation in the foreground is outside a pasture fence of a large ranch. This relict vegetation served as a reference which was compared to the climax or potential natural vegetation described in Soil Sruveys of adjoining counties.(A Soil Survey does not exist for the county in which this vegetation grew.) The range plant community in this "control plot" was dominated by the Four Horsemen of the Prairies tallgrass species. Big bluestem was the most common. Canada wildrye, prairie dropseed, and tall dropseed were also abundant as was sideoats grama and buffalograss to add a definite and distinctive mid-grass and shortgrass layer to the vegetation and it's physiogonomy. Leadplant was the most common legume, but the dominant forb (and locally dominant plant) was Louisiana mugwort or Louisiana sage or white sage (Artemisia ludoviciana).

Vegetation in the background of this slide was presented in the next two slides. This photograph gave a representative landscape-scale view of Red Hills mixed prairie.

Berber County, Kansas. Estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 709 (Bluestem-Grama). Mixed "Short-Grass" Series of Brown et al. (1998). Predominant range site was Loamy Upland with smaller areas of Shallow Prairie. Southwestern Tablelands- Cimarron Breaks Ecoregion, 26a (Chapman et al., 2001).

14. Mixed prairie in Kansas Red Hills- Landscape view that encapsulates the "lay of the land" and the diverse grassland vegetation of mixed prairie in the rolling plains landform of the Plains Border. This land and, some to some extent, its vegetation is a transition between that of the Central Lowlands with it's tallgrass and true prairies and the Great Plains with it's mixed prairie and shortgrass plains. This ecosystem (perhaps the ecological unit of landscape is more appropriate) can be visualized as "ecotonal" between the High Plains portion of the Great Plains and the Prairie Plains of the Central Lowland physiographic provinces.

The vegetation presented here was an accurate composite of that of the Red Hills in Fair to Good ecological (range) condition class. The aspect dominant at this point in progression of the growing season was silver bluestem. It was likely that little bluestem was the overall dominant, but it was much less conspicuous than silver bluestem at phenology of full bloom and peak standing crop. (The largest-- but scattered-- grass clumps are little bluestem). Prairie dropseed was common, but the more mesic and productive species of big bluestem (dominant in protected areas), Indiangrass, and switchgrass were relatively scarce. The increaser to invader (site-dependent) tumble windmillgrass (Chloris verticillata) was locally abundant. Western wheatgrass, sand dropseed (Sporobolus cryptandrus), and tall dropseed (S. asper) were present in small amounts. Sand sagebrush (Artemisia filifolia) was the major shrub with common soapweed or yucca (Yucca glauca) present but far from common. Louisiana mugwort was locally abundant (note small, short forb in immediate lower left foreground). Buffalograss was dominant (as the sole species) across wider microsites (the tan-colored spaces on the diagonal ridge tops).

Barber County, Kansas. Estival aspect, June. FRES No. 38 (Plains Grassland Ecosytem). K-62 (Bluestem-Grama Prairie). SRM 709 (Bluestem-Grama). Mixed "Short-Grass" Series of Brown et al. (1998). Primarily Loamy Upland range site with smaller areas of Shallow Prairie range site. Southwestern Tablelands- Cimarron Breaks Ecoregion, 26a (Chapman et al., 2001).

15. Red Hills mixed prairie (bluestem-grama grassland) community- Detail view of vegetation shown in the two preceding photographs. The larger tufts were little bluestem and silver bluestem which comprised more of the interspace than any other species with sand dropseed second. Sideoats grama, hairy grama, and buffalograss were also common with buffalograss often forming exclusive colonies or stands. The prominent forb in the immediate foreground was Louisiana sage or Louisiana mugwort. Sand sagebrush was the only shrub and it was quite rare (none of it was visible from this vantage point).

Range condition class was high Fair there being almost no big bluestem (the potential dominant), Indiangrass, or switchgrass. On the other hand, invaders like red threeawn (Aristida longiseta), alien annual annual bromes (eg. Bromus japonicus), and weedy Eurasian forbs such as Kochia scoparia were absent indicating that this range was also a "fur piece" from Poor or even low Fair condition class. No accelerated soil erosion was occurring.

Barber County, Kansas. Estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 709 (Bluestem-Grama). Mixed "Short-Grass" Series of Brown et al. (1998). Loamy Upland range site. Southwestern Tablelands- Cimarron Breaks Ecoregion, 26a (Chapman et al., 2001).

16. Louisiana mugwort, western mugwort, white sage, western wormwood (Artemisia ludoviciana)- This forb (primarily an herbaceous plant) is typical of the Artemisia species in being widely distributed (ie. having a large species range). This phenomenon is characterized by having several subspecies or varieties (often depending on which taxonomist's treatment is consulted). The colony of A. ludoviciana shown here was in the Rolling Red Plains of northcentral Texas in mid-spring. The official flora and manual of Texas did not follow the convention of subdividing this species because it was stated that there was little correlation between such taxa and geographic distribution of these subdivisions. Most other taxonomic workers in this geographic region disagreed.

Western mugwort is-- as obvious from this photograph-- a rhizomatous species having numerous daughter plants arising from older shoots which function as a parent plant (ie. another example of a clonal organism).

SMS Ranch, Throckmorton County, Texas. May.

17. Adult plant of western or Louisiana mugwort at post-bloom stage- An extremely hearty individual of A. ludoviciana at the early to mid-fruit ripe stage growing on a oak-hickory- tallgrass savanna in the Ozark Plateau in eastern Oklahoma. Taxonomic treatments by authors in the florae of Missouri and the Great Plains keyed this specimen to A. ludoviciana var. mexicana in contrast to A. ludoviciana var. ludoviciana of the Great Plains physiographic province that was presented immediately above. Some authors treated these subdivisions as subspecies while others interpreted them as varieties. Does any of this matter?

Stoney Point Savanna, Ottawa County, Oklahoma. September.

18a. This is a textbook example of the species composition, physiogonomy, and community structure of mixed prairie on the Southern High Plains. In this one photograph can be seen the tallgrass species of big bluestem, Indiangrass, and upland switchgrass; mid-grasses like sideoats grama and silver bluestem; and the shortgrass species of hairy grama, buffalograss, and a "smigen" of blue grama. Western wheatgrass was absent. The dominant forb was wild alfalfa (Psoralea tenuifolia).

Invaders like red threeawn, annual Bromus species, broom snakeweed, and sand sagebrush "were conspicuous by their absence".

18b. Characteristic sward of mixed prairie in the Southern High Plains- The combination of bunchgrass and bare soil with the dense turf formed by sod-forming grass is one of the most obvious physiogonomic features of this multi-storied grassland.There were the three layers formed by the tall-, mid- and shortgrass species with scattered individual plants of the leguminous forb, wild alfalfa. A shrub layer and soil surface layer (eg. of mosses, lichens, fungi) were both absent.

19. Mixed prairie used as stocker range- Steers (Bos taurus) grazing mixed prairie dominated by sand dropseed with blue grama and needle-and-thread well distributed throughout while western wheatgrass dominated small swales at local scale. Most common forb was Louisiana sagewort or Louisiana mugwort. The relatively tall, dark green stalks in left background were longstyle rush (Juncus longistylis) growing in a normally seepy depression. There were no seeps-- or much moisture anywhere-- in this spring and summer of 2002, the single driest year to-date in Colorado weather records. The remarkable ability of range plants to survive and even grow in extreme drought was illustrated by this example of plains grassland on the semiarid High Plains under devastating drought.

Lincoln County, Colorado. Estival aspect (as modified by drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss, sand dropseed variant). Mixed "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

20. Pristine mixed prairie near its western boundary - Climax vegetation of western wheatgrass, blue grama, and needle-and-thread with abundant shrub cover of fourwing saltbush (Atriplex canescens) so that this mixed prairie-shrub community could be interpreted as either grallsnad or a grass-shrub savannah. This was an example shrub-mixed prairie "mint condition" (Excellent range condition class) that developed near the Front Range of the Rocky Mountains. These "photo-plots" of a type of mixed prairie at its zenith furnished a rare sample of what one imagines the Indians and the first "white intruders" found at the western margin of teh Great Plains. Two other major midgrasses in this range plant community were sand dropseed and, at lesser cover and frequency, plains lovegrass. Forbs were absent for all practical purposes.

This climax range vegetation was not high in biodiversity, either as to species richness, life (growth) forms, vegetational layers, or physiogonomy, but it represented the ultimate mainfestation of mixed prairie on the western Great Plains. For whatever reason(s) this unfenced range was not grazed by livestock though obviously abundant wildlife species including black-tailed jackrabbit (Lepus californicus), pronghorn (Antilocapra americana), and mule deer (Odocoileus hemionus) found this virgin condition range to be a Garden of Eden or Mecca. LIght grazing by wildlife (and insects) was responsible for the lack of substantial utilization and the outstanding vegetational manifestation of this rangeland cover type. Light degree of use of the herbage of this range plant community was shown in the succeeding photograph.

Washington County, Colorado. Late June, late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). No unit in Brown et al. (1998). High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).

21. Composition of mixed prairie on its western boundary - "Photo-quadrant" of the western wheatgrass--blue grama--needle-and-thread--fourwing saltbush mixed prairie savanna described for the immediately preceding set of potographs. Sand dropseed (largest grass clumps as in center-right of this photograph) was featured here so illustrate the light degree of use (by antelope and/or mule deer) of this range herbage. Fourwing saltbush was not included in this view.

Washington County, Colorado. Late June, late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem).K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). No unit in Brown et al. (1998). High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).

22. Floodplain on the plains- Lowland mixed prairie range of alkali sacaton (Sporobolus airoides) and galleta (Hilaria jamesii) on part of the greater floodplain of the Arkansas River in the Southern Great Plains.Western wheatgrass was a distant associate species while blue grama and buffalograss were frequent enough to remind those who, like this photogtrapher, were enthralled by the granduer of these midgrasses that shortgrasses were more commonly the dominant or associate species of grasslands on these semiarid High Plains..

This part of the Southern High Plains was in the seventh or eighth straight year of a devestating drought that had reached the category of Exceptional (highest drought rank on the Drought Severity scale; corresponding to Palmer Drought Index of -5.0). A recent local shower combined with deeper (hence, less dry) soil had permitted greenup of the co-dominant alkali sacaton and galleta. Early morning light on greening grass being properly grazed by cattle was captured in these photographs to tell of the dawning of another day.

Crowley County, Colorado. Late June; late vernal to estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No Kuchler (1964, 1966) unit at the restricted spatial scale of this climax vegetation. SRM 712 (Galleta-Alkali Sacaton). Not a very descriptive (precise) unit in Brown et al. (1998, p. 40), but Mixed "Short-Grass" Series142.13 of Plains Grassland biotic community 142.1 comes closest. Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

23. Co-dominants on flood mixed prairie- Alkali sacaton and galleta dominated a bottomland or lowland mixed prairie on the greater floodplain of the Arkansas River in the High Plains. Western wheatgrass qualified--though barely--as the associate species. Blue grama and buffaalograss were very limited but on local microsites contributed a shortgrass component to an otherwise exclusively midgrass mixed prairie. A recent, highly localized "shower of blessing" in an area caught in the clutches of an Exceptional drought afforded an opportunity for drought-dormant grass to initiate spring growth as shown in these early morning shots on the first full day of summer. Diffuse light (especially in the second of these photographs) of early morning and the peak period of grazing animal activity highlighted the promise of a new day on the drought-prone semiarid High Plains.

The presence of this much dead herbage in the eighth straight year of drought (culminating in the highest drought severity score) presented to students an example of outstanding stewardship of the range: light grazing being practiced to save enough feed for cattle and pronghorn in drought is wise use management of grazing land, and basic common sense. When rain comes--as it always does sooner or later--proper grazing permits grass and other range plants to recover faster and reduces the likelihood of severe range depletion by retrogression induced by drought. In the long run nothing is gained by assisting drought to degrade the range plant community and, perhaps, inflict greater damage on range ecosystems through soil erosion.

This was beautiful range skilfully and wisely managed under the most trying of times. Drought is, over time, the greatest risk (including blizzards) inherent in ranching in the semiarid zone.

Crowley County, Colorado. Late June; late vernal to estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No Kuchler (1964, 1966) unit at the restricted spatial scale of this climax vegetation. SRM 712 (Galleta-Alkali Sacaton). Not a very descriptive (precise) unit in Brown et al. (1998, p. 40), but Mixed "Short-Grass" Series142.13 of Plains Grassland biotic community 142.1 comes closest. Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

24. Galleta on the upper Arkansas- Representative plants on the greater floodplain of the Arkansas River. It was explained above that in minst of prolongued drought this relatively small area had received "showers of blessing" such that ranges therein had growth and plant productivity typical of an "average year". Galleta was grwoing in association with alkali sacaton.

Crowley County, Colorado. Late June: peak anthesis.

25. Anthesis in inflorescence of galleta- The inflorescence of Hilaria species is interpreted as a "...dense, bilatral spike, the spikelets in clusters of three at each node of a zigzag rachis" (Gould, 1975, p. 366). Of these three spikelets the two lateral ones are staminate and two-flowered while the central spikelet is perfect and one-flowered.

Crowley County, Colorado. Late June: peak anthesis.

26. Alkali sacaton on the upper Arkansas- On much of the greater floodplain (not so much the bank or first terrace) of the Arkansas River alkali sacaton and galleta form broad expanses of mesic plains grassland. These are examples of alkali sacaton growing on that range (described above). Alkali sacaton is one of the higher herbage-yielding native grasses. Floodplain range sites are also have extremely high production-potential. A combination of alkali sacaton (with or without other species like galleta) and the high water content of soils on floodplain or overflow sites makes for high herbage yields in the semiarid precipitation zone.

Crowley County, Colorado. Late June: end of (and just past) anthesis.

27. Panicles and spikelets of alkali sacaton-Sahpe of panicles of alkali sacaton vary but toen to have a somewhat pyramid-shape. Spikelets have one floret with an awnless lemma. The purple-tinged glumes and lemmas of the spikelets shown in the second photograph are typical of this species.

Crowley County, Colorado. Late June: end of and just past anthesis.

30. Mixed prairie in Texas Rolling Red Plains- The diverse range plant community presented here included tallgrass, mid-grass, and shortgrass species along with shrubs and a few composite forbs. Little bluestem was the dominant with sideoats grama and silver bluestem associates. Buffalograss grew in the interspaces among the cespitose tall- and midgrass species. Vine mesquite dominated the draws except in the thickets of wild plumb (Prunus sp.). There were traces of sand bluestem and sand sagebrush as postclimax components. Skunkbush sumac and soapweed (Yucca glauca) were infrequent but dominated some microsites. Sand and plains lovegrasses grew sparingly.

Gray County, Texas. Estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Gramagrass Prairie). SRM 709 (Bluestem-Grama). Mixed "Short-Grass Series" of Brown et al. (1998). Central Great Plains- Red Prairie Ecoregion, 27h (Griffith et al., 2004).

32. Rolling Red Plains rangeland as seen by the redman- Although this land is technically in the High Plains section of Great Plains physiogrphic province it is in the an example of Rolling Redlands mixed prairie range in climax condition. Little bulestem is the sole dominant while sideoats grama and silver bluestem are associates. Rich species diversity prevails however with numerous other grass speceis including hairy and blue grama, sand dropseed, buffalograss, Indiangrass, galleta, and curly mesquite present on various microsites. Wild alfalfa was also common as were several composites The only shrubs were sand sagebrush and soapweed yucca.

Wheeler County, Texas. June, early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 709 (Bluestem-Grama Prairie). Mixed "Short-Grass" Series of Brown et al. (1998).Central Great Plains-Red Prairie Ecoregion 27h (Griffith et al,. 2004). Central Great Plains- Red Prairie Ecoregion, 27h (Griffith et al., 2004).

33. Good range gone bad- This range vegetation was conterminous with that featured in the preceding slide. In fact part of that climax condition mixed prairie range was visible in the background of this slide. Range sites were the same. Severe disturbance(s) that could have included previous plowing, overgrazing, wrongly timed or poorly manage fires, etc. (more than likely God in His Heaven only knows what) degrated this range vegetation. This is now largely a sand sagebrush disclimax. Soapweed yucca had also increased condiderably. Perennial grasses were rare and largely replacecd by the Eurasian annual grass, Japanese chess (Bromus japonicus). Annual broomweed (Gutierrezia draculoides) was also common.

Wheeler County, Texas. June, early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K- 62 (Bluestem-Grama Prairie).SRM 709 (Bluestem-Grama). Mixed "Short-Grass" Series of Brown et al. (1998). Central Great Plains-Red Prairie Ecoregion 27h (Griffith et al., 2004). Central Great Plains- Red Prairie Ecoregion, 27h (Griffith et al., 2004).

34. Landscape-scale view of plains and mesa grassland (High Plains mixed prairie ecosystem)- This landscape-scale "shot" caught landform, physiogonomy and structure of vegetation, and typical atmospere on a "plains morning" of a semiarid Great Plains grassland. Blessings of recent rains allowed this superb example of it's range type (Excellent range condition class) to portray it's natural potential at this season. Although generally thought and spoken of as "short grass country" the climax vegetation of this range site (and general range region) is a classic mixed prairie with three pronounced herbaceous layers (short-, mid-, and tallgrass species often with forbs in each) plus a shrub layer (here represented by cholla cactus, soapweed yucca, and/or sand sagebrush on coarser textured soils).

At this early summer stage of phenological development (and delayed growing season precipitation) the tallgrass component was not conspicuous but it was well-represented by upland switchgrass. Buffalograss, the associate species, and small patches of curly mesquite comprised most of the shortgrass layer while blue gramma and galleta, the community dominants, made up most of the vegetation and the predominant mid-grass physiogonomy. (This will be more pronounced for blue grama when it soon sends up sexually reproductive shoots.) Patches of western wheatgrass along with sideoats grama and sand dropseed contribute further to the mid-grass and mixed prairie appearance. Forbs were limited, and mostly composite species at pre-bloom stages. All-in-all: pristine!

Oldham County, Texas. Early estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Blue Grama-Galleta).Grama "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Semiarid Canadian Breaks, 26d (Griffith et al., 2004).

35. Sward of climax blue grama-galleta mixed prairie grassland- Detail photograph of the estival-aspect herbaceous vegetation of the Excellent condition mixed prairie form of plains and mesa grassland presented in the immediately preceding slide. Light grazing by cattle and delayed phenological development due to delayed rains were reflected in appearance of grass, but co-dominant galleta and blue gramma along with buffalograss as the associate species were obvious. Populations of these species were presented at community scale in the next slide.

Oldham County, Texas. Estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al (1998). Southwestern Tablelands- Semiarid Canadian Breaks, 26d (Griffith et al., 2004).

36. Mixed prairie plains and mesa grassland- This is a community scale scene of semiarid steppe in the southern High Plains. This is the High Plains section of the Great Plains physiographic province known also as the Llano Estacado ("Staked Plains"). Here is another view of the cattle range shown in the two immediately preceding slides. Local populations or colonies of the different plant species formed a mosaic or "patchwork" expression of vegetation. Easily discernable species were cholla, galleta (grass with light gray inflorescences in right foreground), buffalograss (the shortest grass and with spots of bare soil interspersed within), and blue gramma (the grass with the darkest green hue and comprising most of the understorey in the area beginning at right background where cholla cactus was the aspect dominant).

Oldham County, Texas. Estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Semiarid Canadian Breaks, 26d (Griffith et al., 2004).

37. Mesa and plains grassland— Shortgrass plains or shortgrass form of mixed prairie depending upon interpretation and which classification of vegetation types is used. Besides blue grama and buffalograss, galleta (Hilaria jamesii) rounds out the three dominant species. Several species ofthreeawn such as Aristida purpurea and A. longiseta are present but mid-grasses like western wheatgrass, sideoats grama, and siver bluestem are absent. Cholla (Opuntia imbricata) lends a savanna-like aspect to this shortgrass country and serves as an emergency feed source in drought if spines are burned off with propane burners. Peak estival aspect, June. Quay County, New Mexico. FRES No. 38 (Plains Grasslands Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 502 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Semiarid Canadian Breaks Ecoregion, 26d (Omernik and Griffith, 2006).

38. High Plains Breaks range- This was one of many varied forms of the Breaks ranges site that is widely distributed on the shortgrass and mixed prairie ranges of the High Plains (Llano Estacado). These grassland communities were entitled and described by Dick-Peddie (1993, ps. 104-106, 113-115) as Plains-Mesa Grasslands. Breaks are typically a grassland range site (again, of various forms), but some expressions of this generic range site are climax shrublands (see Breaks Scrub under Miscellaneous Shrublands). The climax grassland range breaks seen here are of mixed prairie High Plains grassland range having a shrub component consisting of skunkbush or fragrant sumac (Rhus trilobata= R. aromatica), soapweed yucca, broom snakeweed (Gutierrezia sarothrae), and fragrant mimosa (Mimosa borealis) in that order. The grassland vegetation shown here was the Galleta-Indian Ricegrass-Needlegrass Series (Hilaria jamesii-Hymenoxix oryzoides-Stipa neomexica-Mixed Forb Species) of Dick-Peddie (1993, p. 110).

Galleta and New Mexico feathergrass (=needlegrass) were the dominants; Indian ricegrass was present in small amounts as an indictor species and, perhaps, as a relict species. Other common grasses included blue, sideoats, and hairy gramas; buffalograss; silver bluestem, and threeawns (of the Aristida purpurea complex).

Major forb species growing on this specific range were featured immediately below following photographs of skunkbush sumac.

Quay County, New Mexico. June, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). None of the Kuchler units comes close: this omission indicated an incomplete classification by Kuchler (1964, in Garrison et al., 1977) as documented by the more comprehensive list of climax Plains-Mesa Grassland communites provided by Dick-Peddie (1993, ps. 110-111). Likewise there was no SRM (Shiflet, 1994) rangeland cover type that accurately described this rangeland vegetation that was clearly covered by the Galleta-Indian Ricegrass-Needlegrass Series of Dick-Peddie (1993, p. 110). This could be interpretedas as one of "many variations" occurring in the SRM 716 (Grama-Feathergrass) rangeland cover type. A form or subunit of Mixed "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Semiarid Canadian Breaks Ecoregion, 26d (Omernik and Griffith, 2006).

.

44. Prairie bluets (Houstonia nigricans= Hedyotis nagricaus)- OK, another one the taxonomists are rilin' the herd over. Of course, this little High Plains forb is not worth much fuss, but it did add biodiversity (that catch-all virtue of the "natural crowd") on the range and the fraternity of Good Rangemen and True was proud to accept approvial where it could get it.

This range forb is in the madder family (Rubiaceae). Quay County, New Mexico. June.

48. Almost a tallgrass type on the High Plains- This little bluestem-dropseed-feathergrass mixed prairie approached the physiogonomy and had a species composition that resembled that of tallgrass prairie. This was an example of several rangeland cover types recognized by the Society for Range Manageament (Shiflet, 1994) as developing on the Canadian-Pecos Rivers drainage portion of the High Plains portion of the Southern Great Plains. Tallgrass species were represented by little bluestem an dgiant dropseed (Sporobolus giganteus) midgrasses included New Mexico feathergrass, the dominant (at least the aspect dominant), sand dropseed, and sideoats grama; while the shortgrass species of buffalograss and blue and hairy grama were common on local "spots". Relict plants of spike dropseed (Sporobolus contractus) were found on the outside of the fencerow which seemed to "clinch" this rangeland cover type.

It was possible that continued summer grazing of this specific range for a number of years had favored New Mexico fethergrass over the climax warm-season little bluestem and dropseed species. Also, abundant fall and winter moisture contributed to one of the best crops of fethergrass in recent memory such that this cool-season climax member of the community had been extremely productive. Finally, this scene in early summer was prior to the summer rainfall pattern of this climate so that there was very little current growth of the dropseeds and little bluestem.

Shrubs included soapweed yucca and broom snakeweed, but cover and densty of these species was not in excess of what would be expected on high Good range condition class which was the apparent successional status of this properly managed range. There were almost no forbs.

Quadalupe County, New Mexico. June. FRES No. 38 (Plains Grassland Ecosystem). There was no appropriately descriptive Kuchler unit. Nor did Dick-Peddie (1993, ps. 110-111) list a Plains-Mesa Grassland series that was consistent with the published SRM (Shiflet, 1994) description. This was a "tightland", New Mexico feathergrass variant of SRM 708 (Bluestem-Dropseed). Finally there was not an appropriate series offered by Brown et al. (1998). Southwestern Tablelands- Central New Mexico Plains Ecoregion, 26o (Omernik and Griffith, 2006).

49. Feathergrass-Indian ricegrass range- This Plains-Mesa Grassland had a species composition different from any series presented by Dick-Peddie (1993, ps. 104-106, 110-111), but this specific range plant community was part of the Grama-Feathergrass series.. New Mexico feathergrass was dominant and Indian ricegrass was the associate. Blue and black grama were distant "also rans". Soaptree yucca (Yucca elata) and Bigelow sagebrush (Artemisia bigelovii) were localized in microsites and present in a wide pattern of dispersion. This range vegetation whown here was commonly present on uplands at higher elevation above black grama-dominated plains both of which were in the Sacramento section of the Basin and Range physiographic province.Successional statue was not known, but range condition was probably in Good class.

Black grama-grassland range that was below the range vegetation viewed here was interpreted as being in semidesert grassland and was treated in that chapter in this publication. Higher elevation with commensurate cooler ambient temperatures and greater, more effective soil moisture allowed extension of Great Plains grassland, Dick-Peddie (1993, 104-106, 110-111) into the Basin and Range Region.

FRES No. 38 (Plains Grassland Ecosystem). Smaller unit of range vegetation as part of K-57 (Grama-Needlegrass-Wheatgrass). One of "many variations" of SRM 716 (Grama-Fethergrass). No appropriaate series in Brown et al. (1998). Technical mini-editorial: The list of series under Plains Grassland 142.1 (Brown et al., 1998, p. 40) is much too general to be of much use. In comparison Semidesert (Chihuhuan) Grassland 143.1 has 2/5ths again as many series units and the latter is far less diverse in range types, plant species, soils, topography, climate, etc. than the Plains Grassland. Southwestern Tablelands- Central New Mexico Plains Ecoregion, 26o (Omernik and Griffith, 2006).

Lincoln County, New Mexico. June.

52. Xeric expression or form of Great Plains grassland- Range vegetation that was Great Plains-mesa mixed prairie-semidesert (Chihuhuan) grassland transition, a semiarid low mountain grassland. This picturesque foothill range was in the famous Wild Rose Pass in the Arkansas Mountains at an approximate elevation of 4300 feet. This was an example of an "island" of Great Plains grassland within the Trans-Pecos Basin and Range Region resulting in characteristic and indicator species from the drier semidesert grasslands (located to the west and south) growing with the more common and abundant plains-mesa mixed prairie. This range was somewhat degraded (high seral stage community just prior to climax), but it was an approximation of the potential natural vegetation. Blue grama was the general dominant with black grama and sideoats grama associate species. Hairy grama, cane bluestem (Andropogon barbinodis= Bothriochloa barbinoidis), sand dropseed, plains bristlegrass (Setaria leucopila), buffalograss, tanglehead (Heteropogon contortus), and threeawns (Aristida purpurea complex) were also present. Dominant forb was Louisiana sagewort (Artemesia ludoviciana). Shrubs included alligator juniper (Juniperus deppeana), Havard agave (Agave havardii), pricklypear and cholla cactus (Opuntia spp.), splitleaf bricklebush (Brickellia laciniata) and whitethorn acacia (Acacia constricta).

This range type was one of "many variations" of SRM 706 (Blue Grama-Sideoats Grama) or SRM 707 (Blue Grama-Sideoats Grama-Black Grama), or perhaps more descriptively, as a transition range type between SRM 706 or SRM 707 and the mixed grass hillside semidesert grassland, the Grama-Andropogon- Trichachne community of Whitfield and Beutner, 1939, p. 35-36). The latter was covered under Semidesert Grassland. Presence of Agave and Acacia species as well as the high density and cover of cane bluestem in favorable microhabitats were indications more typical of vegetation in the Basin and Range province.

Jeff Davis County, Texas. June, early estival aspect; current growth mostly of shrubs). FRES No. 38 (Pains Grassland). No appropriate Kuchler (1964, in Garrison et al., 1977) unit or Brown et al. (1998) series. Soil Conservation Service (Soil Survey, Jeff Davis County, Texas, 1972) Igneous Hill and Mountain range site in the Mountains Grassland vegetation. Isolated unit of High Plains- Llano Estacado Ecoregion 25i within Chihuhuan Deserts- Low Mountains and Bajadas Ecoregion 24c.

53. Interloper Great Plains-mesa grassland in Trans-Pecos Basin and Range Region- Detail of richly diverse range vegetation on Wild Rose Pass in Arkansas Mountains of the Basin and Range province. The range vegetation on this vlow mountain mixed prairie was generally a grama-bluestem transition range type: SRM 706 (Blue Grama-Sideoats Grama) or SRM 707 (Blue Grama-Sideoats Grama-Black Grama)of the Southern Great Plains with floristic and structural elements from the semidesert mixed-grass mountain grassland mixed grass of the Chihuhuan Basin and Range Region. This latter range type was treated in the chapter, Semidesert Grassland.

Plant species readily distinguished included Louisiana sagewort (= mugwort), conspicuous silver foliage in second slide, whitethorn acacia, Havard agave, and alligater juniper. Blue grama was the dominant with sideoats grama and black grama associates. Cane bluestem was scattered widely but sparse and this was taken as an indicator species of semiarid mountain grasslands to the south and west. Other Gramineae were listed in the preceding caption.

Jeff Davis County, Texas. June, early estival aspect (little current growth of warm-season grasses).FRES No. 38 (Plains Grassland Ecosystem). No appropriate units in Kuchler (1964, in Garricus, 1977) or Brown et al. (1998): both were much too general. Soil Conservation Service (Soil Survey, Jeff Davis County, Texas) Igneous Hill and Mountain range site in Mountain Grassland vegetation zone. Isolated unit of High Plains- Llano Estacado Ecoregion 25i within Chihuhuan Deserts- Low Mountains and Bajadas Ecoregion 24c (Griffith et al. 2004).

54. Plains-mesa grassland- Bluestem-grama mixed prarie in foothills of Davis Mountains of Trans-Pecos Basin and Range. This range vegetation was photographed prior to onset of summer rains leaving the previous season's herbage as a representation of mixed praire foothill grassland. Dominant species made a a "quaratete" of both cane and silver bluestem along with sideoats and bluegrama. Black, hairy, and chino grama were also common along with buffalograss, galleta, plains and bristlegrass. The major forb was silverleaf nightshade (Solanum elaeagnifolium). Presence of sacahuiste or, sometimes, beargrass (Nolina texana), large green clumps, has traditionally been associated with overgrazing and other human-induced disturbances. Powell (2000, p. 13 described grasslands with unnaturally high cover of sacahuiste as "modified". The current author could think of more descriptive terms for the change: degraded and deteriorated are two scientific terms that are appropriate for formal usage. Sacahuiste cover on this range-- aside from an aspect dominance appearance-- was interpreted as no more than light to moderate invasion.

Physiogonomy and structure of mixed prairie plains grassland was obvious in this mixture of mid- and shortgrass species.Cane bluestem specimens approached a height arbitrarily of tallgrass stature.

Brewster County, Texas. June, early estival period but still dormant to early growth stage for most grasses. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 714 (Grama-Bluestem), but variant of bluestem species. None of the series for Plains Grassland by Brown et al. (1998) could "mow the mustard" (too few series provided for this diverse grassland biotic community). Isolated unit of High Plains- Llano Estacado Ecoregion 25i within general Chihuhuan Deserts- Low Mountains and Bajadas Ecoregion 24c.

55. Texas sacahuiste or beargrass (Nolina texana)- This is one of the more widely distributed grass-resembling or liliaceous shrubs in the Great Plains and Trans-Pecos Basin and Range Regions. It is generlly unpalatable, but not enough. It is a poisonous range plant to sheep and goats under some conditions, namely when overstocking forces animals to eat and poison themselves or in years when flowers and fruit are in abundance. It is only flower parts and ripe fruit that cause toxicity: secondary or hepatogenic photosensitization. Hepatotoxicity is thought to be caused by accumulation of crystals from Nolina tissue in the bile duct. Cattle are not usually affected because they consume only leaves (Burrows and Tyrl, 2001, p. 16). Nolina species do provide valuable forage (browse) across some of the Western Range.

Students were referenced to the following references for discussions of sacahuiste poisoning: Kingsbury (1964, p. 56, 453-456), Sperry et al., (1964, p. 32-34), Burrows and Tyrl (2001, ps. 15-18), and Hart et al. (2003, p. 138).

Brown County, Texas. May.

57. Sand dune mixed prairie or, maybe, mixed prairie-shrub savanna- Vegetation is often deceiving. That fundamental principle was examplified by this mixed prairie on dune land. Sparcity of vegetation cover and low density of plants would suggest to the greenhorn a desert, but in reality structure and composition of this range plant community consisted of tall-, mid-, and shortgrass species producing a classic mixed prairie (in spite of sparcity of plants and plant cover). Major grass species included little bluestem, sand bluestem, sand dropseed, sand paspalum (Paspalum stramineum= setaceum var. stramineum)and perennial threeawn (Aristida purpurea complex). There were a few plants of showy fingergrass (Chloris virgata) but presence of this annual species was of little diagnostic utility. Likewise the presence of a few specimens of common sandbur (Cenchrus incertus) suggested nothing beyond the ever-present annoyance of this weed. Under virgin conditions it was likely that big sandreed (Calamovilfa gigantea) and giant dropseed (Sporobolus giganteus) were present as key indicator species. Neither of these climax species was not found at this location.

The deception (and complication) of this dune land vegetation extended to the shrubs that were present. Mixed and shortgrass prairie grasslands and sand shinnery oak (Quercus havardii) shrubland develop in a mosaic of climax vegetation throughout this region. Presence of numerous shrubs that are climax in the "shinnery sands", the sand shinnery range type (ecosystem), were also present. These shrubs-- in certain proportions-- are thus climax components of the vegetation shown in above photographs. This range plant community was actually a transition zone (= ecotone) between grassland and shrubland vegetation such that it developed into a grass-shrub savanna. These shrubs included sand shinnery oak, the scrub growth (= coppice) form of honey mesquite, and (infrequently) sand sagebrush.

An estimate of annual biomass productivity (so as NOT to be confused by accumulated plant tissue that included necromas accumulated in woody species), species diversity, and plant cover of each growing season convinced this photographer-student that this range vegetation was clearly grassland and not shrubland. This conclusion was further bolstered by the almost-always assumption that that there had been some range deterioration (= degree of departure from climax) if, by nothing else the ubiauituous increase in mesquite since arrival of whiteman. Nonetheless, it was also obvious (again, at least to the rangeman taking these photographs) that this range vegetation was a mixed prairie-shrub savanna. The shrubs are a part of this climax.

Forbs included yellow whollywhite or yellow old plainsman (shown above in this chapter) and western sensitive-briar (Schrankia occidentalis) which was introduced in the succeeding photograph.

Local topography or land form on which this range cover type developed was hummocky (circular sandy hummocks) rather than the tall dune form. The first photographs was taken from the bottom of an interdunal basin in foreground with slopes and the rim or crest (top) of the hummock in background. The second photograph was taken from the intra-dune (intra-hummock) mid-slope (foreground) across the basin (which is bottom of this inter-dunal area) to the crest (behind which is another interdunal hummock with its basin, sloping sides, and crest or rim).

Monahans Sandhills State Park, Ward County, Texas. June. FRES No. 31 Shinnery Shrubland Ecosystem & No. 38 (Plains Grassland Ecosystem) transition zone. No truly descriptive Kuchler unit. SRM 708 (Bluestem-Dropseed), and a textbook of the sparse form or expression of this rangeland cover type.There was no appropriate series under the Brown et al. (1998) Plains Grassland biotic community: inadequate Series units for this large and diverse zonal or regional community of plains grassland climax. High Plains- Shinnery Sands Ecoregion 25j (Griffith et al., 2004).

59. Great Plains-Great Basin transition mixed prairie grassland- Landscape-scale photograph of what Brown (1994, p.119) described in a photo caption as a "Plains grassland-Great Basin grassland transition", "... a mixture of both Plains species (Boutelous gracilis) and Great Basin species (Hilaria jamesii, Oryzopsis hymenoides)" and "... shrubs are mostly fourwing saltbush (Atriplex canescens)". The range vegetation shown in this slide was an example of plains and mesa grassland described by Dick-Peddie (1993, p. 119) and quoted in the last paragraph of the preceding slide caption. This climax vegetation was a consociation of New Mexico feathergrass (= New Mexico needlegrass) with blue grama, galleta, and Indian ricegrass approximately "equally divided" and functioning as associate species. Sand dropseed was present at more than "trace amounts", but it was not a major component. Greasewood (Sarcaobatus vermiculatus) and Bigelow sagebrush (Artemesia bigelovii) were the two most common shrubs with greasewood better represented. Fourwing saltbush was present (rarely) and perhaps as a relict species. None of these woody species accounted for more than trace proportions. Broom snakeweed was present but even more rare. Forbs were represented (barely) by Russian thistle and Thurber pepper-weed (Lepidium thurberi).

Relative utilization or degree of use of grass was light even under current conditions of exceptional drought. It was noted that sexual reproduction of feathergrass was remarkable for such short-moisture conditions. Winter precipitation had "saved the day" for this species.

Grand Canyon section of the Colorado Plateau physiographic province.

Coconino County, Arizona. Estival aspect during worst drought (exceptional rating) in Arizona history, June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Gallata Steppe).SRM 716 (Grama-Feathergrass).

60. Vegetation of Great Plains-Great Basin transition mixed prairie- This photograph detailed at community scale the climax vegetation of the New Mexico feathergrass consociation of plains and mesa grassland, a variant of the regional gramagrass-gallata (Bouteloua-Hilaria) climax steppe. Dominance by a cespitose midgrass (a species of intermediate height between tallgrass and shortgrass) produced a physiognomy typical of mixed prairie, but absence of a tallgrass species resulted in absence of one herbaceous layer that was present in some of the other range cover types of mixed prairie.

Cover and dentisty of woody species were so limited that a shrub layer was also absent. This climax community was not a savanna-like shrub steppe, but rare presence of fourwing saltbush was of uncertain interpretation. Brown (1994, p.104) specified presence of fourwing saltbush in a similar transition grassland community located close to the one shown here, but neither Dick-Peddie (1993, p. 104-106) nor the the SRM description of this rangeland cover type, SRM 716 (Grama-Feathergrass), (Shiflet, 1994, ps. 94-95) specifically reported fourwing saltbush for this vegetation. The SRM description (Shiflet, 1994) was limited to eastern New Mexico which was essentially in the High Plains province rather than the Colorado Plateau as shown here. Likewise, none of these descriptions mentioned greasewood which was certainly the most common (least uncommon) shrub and one known to occur here.

Perhaps browsing by livestock and/or wildlife had reduced fourwing saltbush. It was conceivable also that grazing had shifted dominance from the regionally dominant blue grama to the co-dominat New Mexico feathergrass. Existing "on-the-ground" evidence argued against both of these outcomes. Species composition of vegetation in the wide right-of-way of Interstate 40 was not apparently different from that inside the range allotment except that the rarely encountered fourwing saltbush plants were larger in the right-of-way. Right-of-way vegetation had been protected from grazing and routine mowing for several decades and this could explain larger size of fourwing saltbush specimens. Otherwise the only difference between livestock presence and absence appeared to be in degree of use (and not species composition of plant community). Present (and immediately past) grazing management of the range appeared to be ideal, an example of outstanding stewardship.

Fourwing saltbush was present (far right to center midground) on New Mexico feathergrass-dominated range protected from livestock grazing and not subjected to highway mowing (shredding).

Coconino County, Arizona. Early estival aspect (conditions of exceptional drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 716 (Grama-Feathergrass).

61. Patch dynamics in vegetation of Great Plains-Great Basin transition mixed prairie range- These paired photographs showed details of undisturbed vegetation (first or upper slide) and disturbed vegetation (second or lower slide) of a New Mexico feathergrass-dominated (feathergrass consociation) bunchgrass steppe on the Grand Canyon section of the Colorado Plateau province. The localized "patch" in the lower photograph had Russian thistle (round-shape tumbleweed in lower left), greasewood (largest plant; center background), Bigelow sagebrush (to immediate right of greasewood), fourwing saltbush (immediately to right and also behind Bigelow sagebrush), broom snakeweed (right background), and Indian ricegrass (right-center foreground) as well as New Mexico feathergrass in contrast to the nearly single-species stand of New Mexico feathergrasss in the undistrubed patch shown in the upper photograph. This was an example of patch dynamics on a very local scale (microsite-size). Both patches were on highway right-of way not subjected to mowing.

Coconino County, Arizona. Early estival aspect (in exceptional drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 716 (Grama-Feathergrass).

65. Bigelow sagebrush (Artemesia bigelovii)- Both this species and big sagebrush (A. tridentata) grow in the Great Plains-Great Basin transition mixed prairie steppe on the Colorado Plateau. Bigelow sagebrush can be readily distinguished by presence of numerous stems in contrast to the usual single trunk of big sagebrush.

This specimen was growing on the climax New Mexico feathergrass-dominated range and exclosed area shown above. Coconino County, Arizona. June.

66. Galleta-blue grama plains and mesa grassland in drought- Appearance of High Plains (Llano Estacado) mixed prairie in prolonged, severe drought and under current overuse. Galleta was the obvious dominant species with blue grama, buffalograss, western wheatgrass, and sand dropseed all microsite associate species and in that relative mean (overall range community) order of abundance. This range had absolutely no mesquite, but the native plains pricklypear (Opuntia polyacantha)-- seen as small isolated patches in foreground-- had begun to appear at density and cover of an invader (greater amounts than in climax vegetation). It must be borne in mind, however, that overuse of grass had exposed pricklypear prominently. Nonetheless, there was virtually no doubt but what this range was probably being mismanaged-- to some detriment of both range and cattle. Excessive degree of use (overuse= removal by grazing animals of excessive portions of current season's leaves and stems that if conitinued will lead to overgrazing) was indeniable.

The most immediate incontrovertible evidence of current overuse was grazing of young, growing plants of broadleaf milkweed (Asclepias latifolia) by cattle. A. latifolia is one of the more toxic plants on High Plains ranges (perhaps because there are not as many poisonous plant species in this region as in some of the more botanically diverse adjoining ones like the Trans Pecos Basin and Range and Edwards Plateau). Livestock poisoning by broadleaf milkweed is enough of a problem that it was routinely covered in standard textbooks and Agricultural Experiment Station-Extension publications (eg. Sperry et al., undated). In the example shown here it was human management of range and cattle that resulted in milkweed consumption. There was no evidence of toxicity to cattle: apparently quantities eaten were below toxic levels (at time of photograph). If current overstocking does not result in overgrazing (range retrogression due to prolongued overuse) with corresponding damage to basic range resources like soil and watershed features and/or economic losses in livestock (in excess of that from emergency feeding), such periods of overuse cannot automatically be labeled as mismanagement. Cows and calves grazing this range remained in thrifty condition and as the grass species were in semi-dormancy the range was not being severely abused. The situation was that there were indications that current grazing management was allowing invasion by plains pricklypear. More frequent movement of cattle to different pastures or even culling of lower-producing cows might well be more economical in the long run.

Examples of broadleaf milkweed were presented below in this Mixed Prairie portion. The large Brangus cow beside the cholla indicated size of some of these cactus plants.

Guadalupe County, New Mexico. Early estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al (1998). Southwestern Tablelands- Conchas/Pecos Plains Ecoregion, 26n (Omernik and Griffith, 2006).

67. Sward of plains and mesa mixed prairie in drought and without cattle grazing- Details of galleta-blue grama-buffalograss-western wheatgrass-sand dropseed (all are visible) community shown in the preceding photograph except that grass shown in this photograph was not grazed. Vegetation seen here was immediately adjacent to but outside the fence that enclosed the currently overused range of plains and mesa mixed prairie. Difference in degree of use was obvious, but there was little difference in species composition except for absence of broadleaf milkweed and less cover of plains pricklypear. Grazing by cattle had apparently contributed to an increased number of plant species and a somewhat different plant "mixture" (ie. cattle grazing apparently increased biological diversity). Is this sort of increased biodiversity "good" or "bad"?

Western wheatgrass photographed here was in anthesis. Western wheatgrass inside the pasture shown in the preceding slide was grazed to a stubble height of less than two inches and there were no flowering shoots. In other words, even in severe, early season drought cool-season grasses were in the process of producing seed-- where they were not "grazed into the ground".

Degree of use is determined largely by the stocking rate. Proper degree of use (proper stocking rate) is the first and most important of the Four Cardinal Principles of Range Management.

Guadalupe County, New Mexico. Early estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al (1998). Southwestern Tablelands- Conchas/Pecos Plains Ecoregion, 26n (Omernik and Griffith, 2006).

68. Relict plains-mesa mixed prairie (shrub steppe form)- Although this semiarid grassland in the Datil section of the Colorado Plateau was enduring a severe to exceptional drought and in semi-dormancy it was the potential natural vegetation. These two photographs showed the species composition and physiogonomy of a climax mixed prairie grassland with a shrub component that appeared almost as a shrub-grassland savanna. The climax dominant shrub was fourwing saltbush. There was an occasional broom snakeweed (an all-too-common invader on adjacent range), but the vegetation here was in "mint condition". On the extremely sandy soil of this range site Indian ricegrass was the clear dominant with sand dropseed, plains lovegrass, blue grama, and sideoats grama all abundant species and growing as mixed localized "mini-communities". Sand dropseed dominated some microsites. Blue grama, the dominant species of this general regional (monoclimax or ecoregion dominant) was never a local dominant on this sandy range. Galleta was not present (or if missed, it was but a trace).

Cibola County, New Mexico. Early vernal aspect (extreme to exceptional drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). Variant of SRM 502 (Grama-Galleta); SRM 705 (Blue Grama-Galleta) occurs to the east of the 502 rangeland cover type but resembles it rather closely.

Dick-Peddie (1993, p. 104) described this and the mixed prairie example in the succeeding slide, Great Plains grassland-Great Basin grassland transition, as part of the plains and mesa grassland in which blue grama was a common denominator but often co-dominant with galleta on mesas in the northern half of New Mexico. He specified: "On fine-textured soils in the north and northwest, Indian ricegrass (Oryzoides hymenoides) may share dominance with blue grama, or communities can be found with New Mexico feathergrass (Stipa neomexicana) and needle-and-thread (S. comata) sharing dominance with blue grama" (Dick-Peddie, 1993, p. 119). Arizona/New Mexico Plateau- Semiarid Tablelands Ecoregion, 22j (Omernik and Griffith, 2006).

Phenological/species compositional note: photographs of rangeland cover types Wheatgrass-Grama-Needlegrass (SRM 608) & Wheatgrass-Needlegrass (SRM 607) taken in June 2008 gave an atypical representation of  these types. A late spring (abnormally cold and wet) was a boon for needlegrass species and “hard scramble” growing conditions for wheatgrass species. Although slides were taken in early summer, phonological stages of most species— especially western wheatgrass—were those typically taking place much earlier in the growing season. Aspects, especially aspect dominance, structure, and relative composition of these mixed prairie communities were generally those of vernal societies at a time in growing season when estival aspects and societies normally would have predominated. Again, western wheatgrass in particular was underrepresented from average composition (based on relative cover), structure, and overall physiogonomy. Also, in early summer blue grama was still in early vegetative stages of phenology so as to be vastly underrepresented from the standpoint of cover dominance. Simply put, photographs were of the vernal rather than estival societies of these types.

These clarifying notes made, it should also be stressed that these photographs did display clearly the dominance of needle-and-thread (Stipa comata) which has traditionally been regarded as the overall first defining co-dominant of the mixed prairie (Stipa-Sporobolus) association (Dodd in Gould and Shaw, 1968, 1983, ps. 349-351) which traced back to the seminal knowledge of Clements (1920, ps. 122, 135-138) and Weaver and Clements (1938, ps. 523-524). Incidentially, more recent interpretations appeared to have placed needle-and-thread "second in command" to blue grama and/or western wheatgrass as can be seen in titles of potential natural vegetation by Kuchler (1964, 1966) and the Society for Range Management Shiflet (1994) shown below. The photographs presented below--even allowing for aspect dominance and an estival aspect--suggested that initial interpretations by Clements (1920) and Weaver and Clements (1938) and subsequently by Dodd (in Gould and Shaw, 1968, 1983) were closer to the mark.

69. Transition zone mixed prairie- Mixed prairie dominated by needle-and-thread, blue grama, and western wheatgrass in lower foothills of the Southern Rocky Mountains in a patchwork pattern of range vegetation with true mountain mahogany (Cercocarpus montanus) shrubland. This scrub range type was treated in the Mountain Scrub chapter under Shrublands. To reduce confusion the mountain mahogany scrubland was not described here.

Additional important--at least locally so--grasses included Junegrass (Koeleria cristata= K. pyramidata), slender wheatgrass (Agropyron trachycaulum), bluebunch wheatgrass (A. spicatum), Sandberg's bluegrass (Poa secunda), big bluegrass (P. ampla), Canby's bluegrass (P. canby), plains bluegrass (P. arida), squirreltail (Sitanion hystrix), some Indian ricegrrass (Orysopsis hymenoides), occasional plants of little bluestem (Andropogon scoparius=Schizachyrium scoparium), local stands of cheatgrass (Bromus tectorum), and scattered plants of the naturalized, Eurasian crested wheatgrass (Agropyron cristatum).

Forbs were limited but the most common one at this season was whiskbroom parsley (Harbouria trachypleura). Shrubs, other than true mountain mahogany at grassland-shrubland contact, were absent except for an occasional plant of fringed sagewort (Artemisia frigida).

Laramie County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Southern Rockies- Mid-Elevation Forests and Shrublands Ecosystem, 21c (Chapman et al., 2003).

70. Sward of foothill mixed prairie- "Photo-quadrant" of mixed prairie in an area of transition from western edge of Great Plains to foothills of the Suthern Rockies. Needle-and-thread was the overwhelming dominant with western wheatgrass (which was underrepreented in this particular spring-summer period) and blue grama (early in the year for full vegetative expression of it) the associate species. Other grasses included Junegrass, slender wheatgrass, bluebunch wheatgrass, Indian ricegrass, Sandberg's bluegrass, big bluegrass, Canby's bluegrass, plains bluegrass, little bluestem, and, as always, cheatgrass.

Principal forb at this season was whiskbroom parsley. Shrubs were absent except for infrequent fringed sagewort (when this is interpreted as a shrub). This was grassland in purest sense of the term, and it was grassland in Excellent range condition class.

. Laramie County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Southern Rockies- Mid-Elevation Forests and Shrublands Ecosystem, 21c (Chapman et al., 2003).

This next section of mixed prairie range presented four ranges of the needle-and-thread--western wheatgrass--blue grama grazing type (SRM 608) in Excellent, Good, Fair, and Poor range condition class. These four pastures were photographed on the same day (2 June) within about three hours and 25 miles of each other (three pastures were in Niobrara County, Wyoming and one range was in Sioux County, Nebraska). Photographs were taken with a wide-angle (28mm) lense so there were several range sites in each landscape-scale photograph, but for comparative purposes photographs featured the same or similar range sites in their foregrounds which was flatter rangeland on benches and not tops or sides of hills. None of the rangeland presented in these slides was near enough to a sacrifice area to bias views of range vegetation.

Key feature of this range type- The "mixed" characteristic of this form, this rangeland cover type, of mixed prairie was through dominance by three midgrass species. There was not a tallgrass component--at least not as a dominant species--in this type-level range plant community. This was in contrast to the Wheatgrass-Bluestem-Needlegrass rangeland cover type (SRM 606) which had sand bluestem as a dominant tallgrass species. The needle-and-thread--western wheatgrass--blue grama type did,however, include both dominant cool-season and warm-season species. This contrasted with the Wheatgrass-Needlegrass rangeland cover type (SRM 607 ) which lacked a warm-season dominant.

71. Mixed prairie in all its glory; first of a comparison- Central Great Plains grassland dominated by needle-and-thread, blue grama, and western wheatgrass with Indian riecgrass and threadleaf sedge (Carex filifolia) associate species. Forbs included crested tongue penstemon or crested beardtongue (Penstemon eriantherus), silvery lupine (Lupinus argenteus), scarlet globemallow (Sphaeralocea coccinea), and a speciimen of an unknown Astragalus species.

This range plant community did not have a particularily rich flora, but it was in mint condition. This was textbook climax mixed prairie of the central grassland formation, grassland like it was when God had it by Himself. A wll-earned stewardship salute to this private landowner.

Note: this range was being grazed at a light degree of use. It was photogrphed at peak standing crop for cool-season perennial grasses (ie. vernal society of the range plant community) which automatically overrepresented needle-and-thread, western wheatgrass, indian ricegrass, and threadleaf sedge relative to warm-season species like the third dominant blue grama. Viewers should not confuse views or perceptions of vegetation resulting from utilization (degree of use) with those due to species composition. This must also be borne in mind when viewing and comparing ranges shown below.

Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).

72. Sward of western mixed prairie in mint condition- Two 'photo-plots" of the sward of the Excellent condition class range of western mixed prairie presented in the immediately preceding pair of photographs. In the first of these "plots" needle-and-thread and western wheatgrass, which along with blue grama, were the overall dominants, made up the cover in left background while threadleaf sedge dominated most of the rest of this sample of range vegetation. In the second "plot" threadleaf sedge was the local dominant with western wheatgrass and needle-and-thread in control of microsites in the background. Main forb was fringed sagewort or fringed sagebrush. There were a few individuals of the Eurasian weed, goat'sbeard (Tragoypogon dubius).

Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003)

73. Western mixed prairie; second of a comparison- Another range in the western Central Great Plains comprised of needle-and-thread, western wheatgrass, and blue grama. Like the preceding range used as an example of this cover type (two sets of paired photographs just shown) needle-and-thread was dominant and conspicuous. (Recall from introduction to this set of slides that it had been a near-perfect for Stipa comata.) Unlike the first example that was Excellent condition class range the one shown here and in the next photograph, was in Good condition class. This range had been graazed with a greater degree of use (low end of moderate) than the range presented immediately above, but the meaningful difference between between these two ranges was in species composition not utilization.

The range shown here and in the follow-up view of the sward had much less western wheatgrass and blue grama and instead had Sandberg's bluegrass as the associate species. This pasture also had considerably greater cover of cheatgrass. There was also slightly more fringed sagewort on the range shown here. Other species included plains bluegrass, threadleaf sedge, and even Indian ricegrass, but cover (basal and foliar) of these--even allowing for greater degree of use--was substantially less than on the Excellent condition range.

Range sites were similar, at least enough for comparison. No, the difference in species composition had been previous--not current season--grazing management.

Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003)

74. Sward of mixed prairie in Good condition- A "photo-plot" of range vegetation on the Good condition class range introduced in the immediately preceding slide. Needle-and-thread was still dominant and there was still some cover of decreaser forage speciees like Indian ricegrass and threadleaf sedge. This was substantially less than on the Exeellent condition class range presented and described above. There was also considerably greater incidence and cover of cheatgrass at local scale (although little was shown here). Incidence of miscellaneous forbs (mostly commposites) was also greater on this Good than on the Excellent condition range.

Degree of use of the range overall was in the moderate category.

Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003)

75. Western mixed prairie; third of a comparison- A third range of the needle-and-thread-western wheatgrass-blue grama type of mixed prairie in the Central Great Plains. This one was under high fence for the explicit purpose of grazing North American buffalo (Bison bison). Unfortunately for this former reigning ruminant of the central grasslands of the plains this range was in Fair range condition class. Needle-and-thread, generally the defining dominant of mixed prairie in this region, was still the dominant perennial grass. At least this was the situation on this range at end of the growing season for cool-season species (period of the vernal society) and prior to main portion of growth for blue grama, the regional warm-season dominant.

Even though needle-and-thread was the dominant native grass, the dominant range plant on this range (the one with greatest cover, density, and biomass) was the Mediterranean, weedy annual cheatgrass. Cheatgrass was conspicuous as the reddish or off-color purple coloration in the foreground. Naturalized and self-seeded crested wheatgrass was also present as scattered individuals on the degraded range featured in the foreground. On hills in the background there was much less cheatgrass and, in fact, that range vegetation was Good to Excellent condition range like that shown for the "mint" condition range used at start of this comparison. Note, however, that range vegetation on hillsides and hilltops was not compared in any of these photographs. Rather it was vegetation on benches and on rangeland with less relief that was used for comparative pruposes of all ranges. Range vegetation that was presented for purposes of comparison as to species composition was on similar slopes, aspects, and as close to comparable range sites as possible among available pastures.

Likewise, the pasture shown here had degree of use (light) similar to that of the first pasture, the "mint" condition range, and lighter defoliation than that of the previous range that was in Good condition class and had moderate degree of use at time of photograph. It was obvious that past grazing had been considerably greater (heavier degree of use or utilization) on the flatter rangeland (foreground) than on hillsides of the range featured here. This may have been attributable to grazing by cattle in the recent past with buffalo being a recent reintroduction. Evidence of this possibility was the "brand new" high game fence that enclosed this range. It would be an almost foregone conclusion or assumption that beef cattle had been the major species of range animal before bufffalo had been restocked on their former range by the present landowner who quite obviously "had more money than he knew what to do with".

Regardless, this was an example of needle-and-thread dominated mixed prairie in Fair range condition class that can be compared to those of the same range type (and similar range site) in Excellent and Good condition class (above) and Poor condition class (coming up next).

Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).

76. Western mixed prairie; fourth of a comparison- A fourth range of the needle-and-thread-western wheatgrass-blue grama type of mixed prairie in the western Central Great Plains. Can there be any doubt that this pathetic degraded example was in Poor condition class? The green (and gnawed down) spots were remains of needle-and-thread and western wheatgrass. The silvery bunches were fringed sagewort. Reddish brown patches were local stands of cheatgrass. The one taller, green bunch of grass was crested wheatgrass which, incidentially, attested to the low palatability of this introduced and naturalized range grass compared to palatability of native grasses like needle-and-thread and western wheatgrass. There was also Sandberg's and plains bluegrasses along with the native annual, sixweek's fescue (Festuca octoflora).

Degree of use on palatable decreaser species was relatively high or close under heavy grazing. Obviously there was little grazing use made of fringed sagewort and invaders like cheatgrass. This Poor (and sadly unfortunate) range had a long history of overuse (obviously stretching over a number of years) so that the misuse had gone to the state of overgrazing. This range was in such a state of degradation (retrogression of range vegetation on this sere) that it almost required a "crime scene uinvestigator" to identify "species of the corpse". Compare the stewardship of this landowner (or renter) and, maybe, previous graziers to that of the good and faaithful stewards wisely using the Excellent and Good condition class ranges presented previously.

Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).

77. 'bout droughted-out but a mixture sho' 'nough- A relatively grass species-rich "sample" in two 'photo-plots" of climax mixed prairie in the Central Great Plains. Needle-and-thread, blue grama, and western wheatgrass were about equally dominant on this ungrazed (perhaps deferred) range. Sideoats grama, buffalograss, sand dropseed, red threeawn, hairy grama, and cheatgrass were other species that were varied from infrequent (eg. hairy grama) to abundant at local scale (eg. sand dropseed, buffalograss, sideoats grama) Cheatgrass was limited to local disturbed spots. Forbs were extremely limited with incidental composites comprising most of these.. The most common (though infrequent) shrub species were plains pricklypear and soapweed yucca.

The plants on this range were largely dormant in early summer during second year of a moderately severe drought. This combined with recent absence of grazing resulted in these photogenic shots of the potential natural vegetation on a western expanse of Central High Plains.

Pawnee National Grassland, Weld County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006).

78. Shortgrass Plains disclimax- A mixed prairie in far-western edge of Central Great Plains degraded to nothing but buffalograss and plains pricklypear. Cause of thee severe retrogression and range depletion was not known. Overgrazing is always a "chief suspect", but it is also possible that some ignorant (and euqllly daring or super-optimistic) sodbuster tried his hand at raising wheat on this marginal land. Regardless of cause, this was disturbance climax on shallow-soil, "tight land" the climax range vegettion of which was blue gram-buffalograss shortgrass plains. Local patches of blue grama were still present as, for example, in the small depression at far right midground.

Although the present vegetation on this deteriorated range was shortgrass-pricklypear, and the potential natural or climax vegetation is still only shortgrass (iel classic "shortgrass plains", it was included at this location (as well as in the Shortgrass Prairie chapter) because of it close spatial proximity to the actual mixed prairie range types.

This was a different range site from that of mixed prairie shown in the immediately preceding slide, but its physical closeness to that range justified placement of this sample of shortgrass prairie in this location within the mixed prairie chapter.

Weld County, Colorado. Late June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss).SRM 611(Blue Grama-Buffalo Grass). Degraded state of Grama "Short-Grass" Series, 142.12 of Plains Grassland biotic community, 142.1 Brown et al. (1998, p. 40). High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006).

79. Central Plains mixed prairie- Another Central High Plains example of the needle-and-thread--blue grama--western wheatgrass cover type, in this instance with a sand sagebrsh (Artemisia filifolia) comprising a pronounced shrub component. Plains pricklypear and soapweed yucca were distant second- and third-place shrub species. Other important grasses included sand dropseed, buffalograss, sideoats grama, red threeawn, squirreltail bottlebrush, scattered individuals of sand bluestem, and, of course (though quite limited), cheatgrass. .In this early estival society the most common forb was prairie or western spiderwort (Tradescantha occidentalis). Scarlet globemallow was sporadic in occurrence. Other forbs at this season were incidential composites like the wavyleaf thistle (Cirsium undulatum) which is a nonweedy (on range), short-growing, native perennial.

This range was obviously in high Good to Excellent range condition class depending on which part of the vegetation one chose to evaluate.

Central Plains Experimental Range, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)

The sandhills range presented in the section immediately below was clearly dominated by needle-and-thread with blue grama as associate species. It was essentially missing a tallgrass (bluestem and prairie sandreed) component although individuals of these species were present. Perhaps tallgrass species had been grazed out although this seemed unlikely. Also a cold, wet, late spring over this region had retarded phenological development of warm-season grasses while resulting in a standing crop of needle-and-thread seldom seen. Conversely, species composition dominated by needle-and-thread and blue grama was consistent with the observation of Dodd (in Gould and Shaw,1983, p. 350) that these two species “are dominant in a limited number of areas with sandy soil”. Whatever the explanation, there was only miniscule cover of sand and little bluestems on this range. Range vegetation shown here was an island of mixed prairie characterized by sand sagebrush in a “sea” of  mixed prairie dominated by the shortgrasses, blue grama and buffalograss.  Range vegetation presented was obviously a variant of sand sagebrush prairie with range condition class (sucessional status) unknown.

Morgan County, Colorado.Late June, but spring-summer growing season was delay such that this was still vernal aspect (vernal plant society). FRES No. 39 (Prairie Grassland Ecosystem). K-63 (Sandsage-Bluestem Prairie).

80. Central Plains Sandhills mixed prairie- Landscape-scale view of needle-and-thread dominated-mixed prairie in sandhills of western High Plains. Blue grama was the associate plant species in this range vegetation in which there was no characteristic tallgrass species. Sand sagebrush provided an infrequent though defining shrub component in this range plant community. Plains pricklypear was the second important shrub species on this range. Species composition and structure of range vegetation was relatively limited and fairly simple (ie. not a range plant community of remarkable biodiversity). There was, however, a major warm-season and major cool-seaosn grass species so as to have pronounced differences in seasonal aspects and societies (even if simple). Also, just two major grass species resulted in both bunchgrass and sod- (sodforming) grass components as well as (by traditional usage) midgrass and shortgrass growth forms in this climax range plant community.

This range type was mixed prairie (of dominant and distinguishing midgrass and shortgrass species but without tallgrasses), and with infrequent shrub cover. This was grassland and not savanna; mixed prairie not tallgrass prairie (with distinction from the latter being critical and explained lower in this caption).

Nor was this range type a form of true prairie. Arguably this climax grassland could be intepreted and described as true prairie from the standpoint of dominance by needle-and-thread or as a transition form of prairie, but blue grama was present at such cover, density, and constance as to be always either an associate or, less commonly, co-dominant. Such constant presence and role of blue grama unquestionably placaed this grassland vegetation in mixed prairie, the Stipa-Bouteloua association (Clements, 1920, p. 135-139) and not in true prairie, the Stipa-Koeleria association (Clements, 1920, ps. 121-131). In this classic and seminal monograph there was a Stipa comata consociation listed for both true prairie and mixed prairie (Clements (1920, ps. 122, 137, respectively ), but a major role of blue grama (co-dominant or associate) as evidenced by a Boutelous gracilis consociation was limited to mixed prairie (Clements, 1920, p. 137). Furthermore, eleven lines below his listing of consociations, Clements (1920, p. 137) cited an earlier survey and description that placed grassland near Akron, Colorado in mixed prairie. Range vegetation presented here was photographed in the vicinity of Akron, Colorado.

Climate was also a distinguishing factor in defining this range type. Development of this climax vegetation in the sermiarid rather than the subhumid zone to the east was a major difference and a distinguishing feature that also placed this range type closer to mixed prairie than true prairie. Clements (1920, p. 122) drew the western boundary of true prairie to aproximately the 98th meridian. Range vegetation shown here was to the west of the 101st meredian well within the vegetational zone of true prairie (Clements, 1920, ps. 136-137).

It was also stressed that the land form and soils of these sandhills should not be confused with the Nebraska Sandhills which are located to the east and in a generally more moist precipitation zone. Range vegetation in the Nebraska Sandhills varies along isohytes (as well as among other environmental variables), but these various plant communities are primarily postclimax tallgrass prairie whereas climax vegetation of the sandhills to the west is mostly various types of mixed prairie. Likewise, there is a similar overall difference between the postclimax tallgrass prairie of the sandhills or duneland in the Southern Great Plains (as for example in northwestern Oklahoma) and mixed prairie of the sandhills shown here. There is an obvious unity of sandhills mixed prairie and sandhills tallgrass prairie both as to land form, soils, and plant species shared in common. Sand sagebrush was the most conspicuous of shared defining species. This was explained in the two rangeland cover type descriptions provided by the Society for Range Management (Shiflte, 1994, ps.74, 99) that could be applied--corrrectly and precisely-- to this needle-and-thread mixed prairie vegetation. Neither of these descriptions--in the current author's opinion--distinguished clearly between mixed and tallgrass prairie forms or variants within range types that justifiably (in this worker's view) could have been split into separate rangeland cover types for sand sagebrush-tallgrass prairie and sand sage-mixed prairie types.

Morgan County, Colorado. Late June- late vernal aspect; soft grain stage in needle-and-thread. FRES No. 38 (Plains Grassland Ecosystem). No appropriate Kuchler unit. SRM 605 (Sandsage Prairie) and/or SRM 722 (Sand Sagebrush-Mixed Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006)

81. A western sandhills mixture- Vegetational mosaic of Stipa-Bouteloua mixed prairie on sandhills of the Central Great Plains. Local (separate) patches of needle-and-thread consociation (background) and blue grama consociation (foreground) with sand sagebrush providing a woody component to both. In this overall range plant community needle-and-thread was the dominant and blue grama the associate species. In local spots blue grama was the dominant, if not the exclusive, species (foreground, both photographs). Other grasses commonly (widely) associated with needle-and-thread and blue grama (eg. sand dropseed, buffalograss, sideoats grama, red and purple threeawns) were limited almost to point of nonexistance. The two major climax (decreaser) grasses did, however, furnish both warm-season and cool-season species to produce pronounced seasonal aspects and societies on otherwise simple (though never boring) species composition and structure of range plant community. These two species also contributed both a bunchgrass and sod (sodforming) grass and, by conventional terminology, a midgrass and a shortgrass. In effect, there was considerable diversity and variation as to life (growth) form and layers of vegetation for such a limited number of species and groups of range plants. .

Forbs were as limited and, in fact, of no obvious consequence. Shrubs were present as sand sagebrush, a definng species (eg. sand sage mixed prairie) though one more conspicuous than dominant as to relative cover, and plains pricklypear. As could be seen throughout this Mixed Prairie (as well as the Shortgrass Prairie) chapter, plains pricklypear was the single most consistently present or constant shrub on the semiarid grasslands of the Great Plains. This included being associated with more domiant grass species, on more soils (associations and/or series) and land forms, and in more ecoregions than any other woody plant.

Morgan County, Colorado. Late June- late vernal aspect; soft grain stage in needle-and-thread. FRES No. 38 (Plains Grassland Ecosystem). No appropriate Kuchler unit. SRM 605 (Sandsage Prairie) and/or SRM 722 (Sand Sagebrush-Mixed Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006)

82. Needle-and-thread consociation in Central Plains Sandhills- Stipa comata is the number one dominant and the first defining species of the climax mixed prairie (Clements, 1920, Weaver and Clements, 1938, Dodd (in Gould and Shaw(, 1983). While difficult--if not impossible--to show conclusively, it is generally assumed from common observtion that heavier and more continuous (or frequent) commercial grazing has resulted in widespread increase in blue grama relative to the usually taller-growing needle-and-thread. It could be argued that such a shift from one climax co-dominant to the other did not amount to a change in successional status of range plant communities. Plus, any such change in relative cover (and consequently in species composition) from dominance by cool-season to warm-season grass was a major practical--an economically advantageous--change from the standpoint of range cattle production. With decreases in needle-and-thread and corresponding increases in blue grama, beef cattle could graze on better summer pasture (have nutritionally superior diets) when there is less risk of animal death (and tremendous economic losses) due to blizzards. There are at least two other obvious advantages of blue grama over needle-and-thread: 1) blue grama cures better for winter forage and 2) blue grama does not have the potential for mechanical injury to animals posed by the sharp callus on the lemma of needle-and-thread.

These facts of ranching notwithstanding, from an ecological perspective dominance of mixed prairie on many (probably most) range sites indicates range plant communities closer to the potential natural (pre-Columbian) vegetation. Dominance ("first among equals") by needle-and-thread indicates he successional "benchmark", the vegetation development "highwater mark" of some range types of mixed prairie and of mixed prairie in genera.

Such a state of climax range vegetation was shown in these two photographs, the first of which presented the general physiogonomy while the second gave detail of the sward of a needle-and-thread consociation. Presence of sand sagebrush as the major shrub of this climax mixed prairie community was also emphasized.

Emphasis was laid on three other points. First, these photographs were taken in a year that was extremely favorable for growth and productivity of Stipa comata A cold wet period from late winter through spring resulted in an "extra good year" and an extraordinary crop of biomass by needle-and-thread. Second, photographs were taken in late June at peak standing crop for needle-and-thread, a cool-season species, and before blue grama, a woarm-season species, had made more than mid-stage vegetative growth. This resulted in photographs that emphasized cover, density, and relative composition of the former more than the latter. Finally, this range professor and advocate of sound grazing land management had to mark the outstanding stewardship and obvious love of the land demonstrated by the owner and/or manager of this rangeland.

One of the goals of this publication was to highlight the best in stewardship of natural resources so as to provide students with outstanding examples of conservation and wise (proper) use management of the land. This example of needle-and-thread--blue grama mixed prairie in Excellent range condition class furnished a superb standard for which any range manager could strive. Cattle of quality equal to that of the range they grazed had just been gathered and the photographer was unable to show the principal tool by which this range was being cared for and left unimpaired for the landowner's grandchildren.

Morgan County, Colorado. Late June- late vernal aspect; soft grain stage in needle-and-thread. FRES No. 38 (Plains Grassland Ecosystem). No appropriate Kuchler unit. SRM 605 (Sandsage Prairie) and/or SRM 722 (Sand Sagebrush-Mixed Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006)

83. Growing by bunches in the sandhills- Several plants of needle-and-thread on the sandhill range described in the above section. The cespitose (bunched or tufted) growth habit of this species was evident. These plants were in stages of both asexual (vegetative) reproduction and sexual reproduction: shoots (tillers only; no rhizomes or stolons) and fruits (caryopses), respectively. A top-down view of Stipa comata was given in the succeeding slide.

Morgan County, Colorado. Late June- late vernal aspect; soft grain stage in needle-and-thread.

84. Fulfilled and being fulfilled- Needla-and-thread at peak standing crop and with grain in soft-dough stage "accompanied by" plains pricklypear in full bloom. This "photo-quadrant" was on the "mint condition" sandhills range featured in this section and dominated by needle-and-thread and with blue grama as the associate species (Stipa comata-Bouteloua gracilis mixed prairie). Sand sagebrush was present as a defining--though certainly not a dominant--climax species of this range vegetation, hence the Sand Sagebrush Mixed Prairie rangeland cover type (SRM 722). Plains pricklypear was also a climax species of this needle-and-thread--blue grama sandhills range.

This photograph with plains pricklypear growing in a climax stand (a consociation) of needle-and-thread, the regional dominant species of mixed prairie, demonstrated the fact that plains pricklypear, like sand sagebrush, is a climax species of this rangeland vegetation. It must be strongly stated and clerly explained that these two woody species are native components of the climax or potential natural vegetation only at relative abundance (ie. general or overall density, cover, presence, biomass) that is natural, where natural is as a minor component. Excess abundance (excessive cover, biomass, density, etc.) of either of these two shrubs constitutes brush (noxious woody plants) invasion and is both symptom and partial cause of range degradation (= retrogression). The relative "amount", the percentage composition or proportion, of pricklypear or sagebrush is what determines whether these shrubs are native woody components of climax vegetation or brush. At the proportion of plains pricklypear preented here this would clearly be brush invasion, but this shrub was present overall in the plant community of this range at much lower relative cover and biomass than shown in this "photo-plot", the purpose of which was simply to show both the dominant grass (needle-and-thread) and plains pricklypear as native plants on sandhills mixed prairie.

This photograph also presented both species in sexual reproduction: plants of both species either fulfilled (plump, ripening caryopses of needle-and-thread) or being fulfilled (flowering stage as prelude to fruit and seed production in plains pricklypear). Life and annual cycles of both species were being completed; each species was perpetuating itself with "re-shffling" of the gene deck. The magic and mystery of life portrayed through range plants.

Morgan County, Colorado. Late June- late vernal aspect; soft grain stage in needle-and-thread.

85. Stand of needle-and-thread- Consociation of Stipa comata on an Excellent condition class range in a more western part of the Central Great Plains. The genus Stipa, including all those split-out, cladistically invented genera in Barkworth et al. (2007), is one of the dominant and defining taxon of the once-great grasslands of the interior of North America. Clements (1920, p. 114) interpreted the climax vegetation of continental interior at the most extensive scale of a plant community as the Grassland Climax (Stipa-Bouteloua Fomation) which included six Associations, one of these being the subject of this chapter which is Mixed Prairie (Stipa-Bouteloua Association). S. comata was the Stipa species that defined (and furnished the first name for) the association of the mixed prairie in the Clementsian model (Clements, 1920, ps.135-139). Green needlegrass (S viridula) was also important and had its own consociation (Clements, 1920, p. 137) as was porcupinegrass (S. spartea), which was the equivalent dominant species of the True Prairie (Stipa-Koeleria Association). Yet it was S. comata that "headed the ticket" of the Mixed Prairie (proper name) as interpreted by Clements (1920, p. 122): "Stipa spartea is the most typical domiant of the true prairies, while S. comata belongs primarily to the mixed prairies". Nonetheless even on True Prairie one of the major consociations of the association was that of S. comata (Clements, 1929, p. 122).

Dodd (in Gould and Shaw, 1983, ps. 349-351) adopted and preserved in the basic Agrostology text the climax (association) interpretation of Clements, 1920). In addition, Dodd was more specific as to which species were dominants and associates on the general kinds of range sites. Weaver and Clements (1938, p. 523) listed needle-and-thread first as "major dominants of the widest distribution" of midgrass species in the mixed prairie.

Needle-and-thread is the plant, the number one--most major and first dominant--species (ie. the defining plant species) of the mixed prairie in the successional sense, "the alpha plant" of the mixed prairie climax; even though blue grama likely furnishes more feed for range animals as the mixed prairie currently exist.

Ecological sidebar: this same relationship also held for the pre-Spanish Pacific Prairie on which S. pulchra, purple needlegrass, was the one dominant of the association "which far overshadows all the others" (Weaver and Clements, 1938, p. 526). Stipa is one damn important genus in defining major units of North Amereican grasslands.

Laramie County, Wyoming. Late June; peak standing crop.

86. Whole plants (shoot portions) of needle-and-thread- Thye cespitose (bunched or clumped) habit of needle-and-thread was conspicuous in this photograph which also introduced the prominent panicles with ripening caryopses inside the long-awned lemmas. These latter features were shown immediately below. The individual plants shown here were relatively small for this species. These particular plants had established on a road cut made a few years earlier and these appeared to be young individuals (genotypes) of needle-and-thread. This seeding-in ability is another testament to the survuval and dominance qualities of this outstanding native species.

A good general and practical reference fo needle-and-thread was the Natural Resources Conservation Service Plant Guide (Ogle, 2006).

Niobrara County, Wyoming. Late June; peak standing crop.

88. Florets of needle-and-thread- The long-awned lemmas surrounding caryopses (grains) is a hallmark feature of needle-and-thread, the number one and major defining dominant of the mixed prairie. This is also a morphological characteristic that can inflict mechanical injury to grazing animals. This drawback does not override the forage value--both yield and nutritive content--of this climax species.

Laramie County, Wyoming. Late June; hard-dough stage.

89. Another important needlegrass- Stand of green needlegrass (Stipa viridula) on a postclimax tallgrass prairie in Nebraska.Sandhills. Green needlegrass is a midgrass species that is more typical of the mixed than of the tallgrass prairie. For that reason some photographs of S. viridula were included here even though the examples were, strictly speaking, growing on tallgrass prairie range. Clements (1920, p.137 ) recognized a green needlegrass consociation for his Mixed Prairie (Stipa-Bouteloua Association). Even though green needlegrass is a dominant on some mixed prairie range sites, it is needle-and-thread that is the defining overall dominant of the mixed prairie.

Fort Niobrara National Wildlife Refuge, Cherry County, Nebraska. Late June; grain-ripe phenological stage.

90. Representative of green needlegrass- A single plant of green needlegrass in the stand introduced in the immediately preceding slide was used to show habit and general features of this cespitose species.

The Natural Resources Conservation Service Plant Guide for green needlegrass (Knudson, 2005) was recommended as a semi-technical reference.

Fort Niobrara National Wildlife Refuge, Cherry County, Nebraska. Late June; grain-ripe phenological stage.

91. nflorescence of green needlegrass- Panicle on one of the plants growing in the stand on postclimax tallgrass prairie that was presented above.

Fort Niobrara National Wildlife Refuge, Cherry County, Nebraska. Late June; grain-ripe phenological stage.

92. Floral reminiscence of an arachnid resemblance- Western or plains spiderwort (Tradescantha occidentalis), Commelinaceae (dayflower family), on Great Plains mixed praririe. This monocotyledon is often the most common and locally dominant forb on mixed prairie ranges in higher condition classes. The specimen in the first of these slides was on a range featured below that represented the needle-and-thread--western wheatgrass cover type (SRM 607) whereas the specimen in the second slide was on a range described below that was as an example of mixed prairie of the western wheatgrass--blue grama--needle-and-thread type (SRM 608).

First photograph from Sioux County, Nebraska; second photograph from Washington County, Colorado. Late June, full-bloom stage.

93. About done for this year-A few plants of western or plains spiderwort that were "winding down" for this year's growing season. Fruit was ripening and shoots were senescing and about to enter dormancy. These plants were on climax western wheatgrass--ble grama--needle-and-thread-dominated mixed prairie where they were only one of several range forbs included in this section.

Niobrara County, Nebraska. Late June.

94. In Excellent company- A prime specimen of crested tongue penstemon (Penstemon eriantherus) on Excellent condition class mixed prairie of needle-and-thread, western wheatgrass, blue grama, Indian ricegrass, and threadleaf sedge. The range that this beauty was growing on was presented and described above. Some of the other range plant species growing on this same "mint condition" range (eg. threadleaf sedge) were shown below with other dominant or otherwise major range plants.

Niobrara County, Wyoming. Late June; full-bloom stage.

95. A crested tongue: what more could anybody want?- Up close views of the flowers of crested tongue penstemon growing on the Excellent condition mixed prairie range described above.

Niobrara County, Wyoming. Late June; full-bloom stage..

96. Narrowleaf (narrow-leafed) or narrow beardtongue (Penstemon angustifolius ssp. angustifolius)- This Penstemon species does not typically grow as large (or as showy) as beard tongue penstemon just shown, but it is another species of forb on the western part of mixed prairie. This one was also growing on a range described previously (and also in Excellent range condition class).

Sioux County, Nebraska. Late June; full-bloom stage.

97. Mixed prairie on the Central Great Plains- Diversity in several forms (species composition, cool-season vs. warm-season species, plant community structure, microrelief of land surface) was present on this mixed prairie range in the central Great Plains. This pasture had historically been subjected to heavier grazing than the one presented in the preceding three-slide example. (This one was on a different research station.) The range shown here had substantially greater relative cover of buffalograss and conspicuously less ralative cover of needle-and-thread and sand dropseed. There was also somewhat greater cover of plains pricklypear though much of this effect was due to greater visibility of the soil surface on the shortgrass form. The most conspicuous difference in species makeup on this shortgrass variant of mixed prairie was absence (or nearly so) of sand sagebrush. Genus Artemisia was instead represented by fringed sagewort (A. frigida).

This shortgrass, sod prairie was "tight land" (more clay) versus somewhat of a "sandy land" range in the previous example that was more of a bunchgrass and sagebrush prairie. Thus differences in species composition and vegetational structure between this example and the one presented immediately above were due to different range sites as well as degrees of use (grazing intensity). Both pastures were grazed by beef cattle.

Major grasses were blue grama, western wheatgrass, buffalograss, and needle-and-thread with relative cover (= % species composition) varying depending on microsite. Overall, blue grama was dominant. Sixweeks fescue and little barley (Hordeum pusillum) were two native annual grasses that were locally common to dominant: Major forbs included wild alfalfa or slim scurfpea (Psoralea tenuifolia), fringed sagewort, western spiderwort, and wavyleaf thistle. Scurfpea was represented by several light-green, bushy plants in the fore- and midgroundbush. Shrubs were limited mostly to plains pricklypear with some soapweed yucca.

A composite "sample" of this range vegetation was presented in the first of these two slides. The second slide featured a shallow drainage (across the foreground narrowing down going to background) dominated by western wheatgrass.

.Central Plains Experiment Station, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)

98. Only neophytes and the unappreciative see monotony in mixed prairie (even if it is short)- A shortgrass varaint of the needle-and-thread--blue grama--western wheatgrass cover type on the Central High Plains. These were two more views of the same range subjected to long-term heavy grazing that was introduced in the preceding (immediately above) two-slide set. In spite of the short stature of range plants (partly a consequence of heavy grazing)

The second of these two photographs presented details of the sward of the sodgrass (= shortgrass) community form of mixed prairie. Species in this second 'photo-quadrant" included included blue grama (the circular patch in foreground), buffalograss (yellowish-green "carpet" in left background and right midground), western wheatgrass (most of foreground around circle of blue grama and extending back to buffalograss), pricklypear (center background), and sand dropseed (background behind pricklypear). Western or prairie spiderwort was preent at sparse density and not distinguishable from grass at these distances.

The next (immediately below) two-slide set presented greater detail of composition and structure of the shortgrass component at closer camera range.

Central Plains Experiment Station, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)

99. But it can be short- Two successively closer-in views of sward of a predominately shortgrass form of mixed prairie in Central High Plains in this photograph and the one following it. Sward in this photograph was dominated in background by western wheatagrass and by blue grama and buffalograss in foreground. Sand dropseed, needle-and-thread, and sixweeks fescue were present in background along with plains pricklypear.

Central Plains Experiment Station, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)

100. Short up close- Plot of sward of the Central High Plains blue grama--western wheatgrass--needle-and-thread mixed prairie described immediately above and presented here at closer camera distance. This photograph showed the relative cover and sod features of the shortgrass component of this mixed-grass (both short-and midgrass species) prairie range. Note the proportion of land surface that was bare ground even in the sodgrass (vs. bunchgrass) form of mixed prairie. This can be compared back to the first (and at greater-camera-distance) photographs of this range vegetation to reveal that the foliar plant cover of even the sodgrass form of mixed praire includes a lot of bare soil surface. This illustrated the potential for soil erosion even with range of this type in proportionately high successional status. This range was in Good to Excellent range condition class even though it had been heavily grazed (fairly high degree of use). Students should not confuse utilization (degree of use; extent of defoliation) with successional status relative to climax (range condition class).

Vegetation in this "photo-quadrant" was dominated by blue grama and buffalograss with a few larger plants of fringed sagewort. Even in the ungrazed state these two co-dominant shortgrass species are never very tall although sexual shoots of blue grama sometimes approach a midgrass height (say, two feet under ideal growth conditions). This was especially the case for this vegetation in early summer before blue grama has much flowering and grain production.

Central Plains Experiment Station, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)

101. Closer still, and confusing- Dead sexual shoots (amber-colored with large, full panicles) of sixweeks fescue were still rooted within live and growing shoots of western wheatgrass. At first flush a range examiner unfamilar with this vegetation could be easily confused by "what was what" in this local stand. Sixweeks fescue (like other species bearing the "sixweeks" adjective) is an ephemerial grass, an annual that completes its life cycle extra fast (as short as five to nine weeks perhaps) even by annual standards. Sixweeks fescue is a cool-season annual.

Benefits--hence, evolutionary adaptation--of this pattern of resource allocation on the harsh habitat of the drought-prone, semiarid Great Plains are obvious. A different strategy (Grime, 1979) for adaptation to stress and survival to reproduce in this severe environment was evolved by the cool-season perennial, western wheatgrass. Evolution of different strategies (Grime, 1979) permits these two native range grasses to exploit different resources and conditions so as to occupy different ecological niche even while living side-by-side (and for all rangemen know even to root graft).

These seemingly drab and otherwise unspectacular species provided examples of Darwinian fitness, the degree to which a species, ecotype, or genotype is adapted to its environment so as to leave ecologically optimum numbers and quality of progeny (offspring). This is natural selection or "survival of the fittest", the phenomenon by which those organisms that are best adapted (as determined by their genes or gene action) to their habitat leave the greatest number of competitive offspring (and their genes) to perpetuate their kind (species, ecotype, genotype) in the eternal "struggle for esistence". This is the theory of evolution as first introduced formally by Charles Darwin and Alfred Wallace on 1 July, 1858 and continually refined by generations of biologists. For those with lesser minds (and the Creator whose grand design it is) it is another kind of joy just to revel in the beauty of these species and their own little world.

Central Plains Experiment Station, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)

102. Sixweeks fescue (Festuca octoflora= Vulpia octoflora)- Plants of sixweeks fescue growing on a climax--and heavily grazed--mixed prairie range dominated by needle-and-thread and western wheatgrass in the Central Great Plains. Sixweeks fescue is a native cool-season annual grass that is frequently associated with dominant perennial grasses, especially under disturbance and greater degrees of use.

Sioux County, Nebraska. Late June; hard-dough phenological stage with plants progressing to senescence.

103. Panicles of sixweeks fescue- Two panicles on sixweeks fescue plants that were presented in the preceding two photographs. Sioux County, Nebraska. Late June; hard-dough phenological stage.

104. At its zenith- Two ranges of climax mixed prairie dominated by needle-and-thread and western wheatgrass in Central Great Plains. One range (first of these two photograhs) had been lightly grazed during the current growing season (grazed only in spring). Dominance of the vernal to early estival aspects (societies) by needle-and-thread, in a year of nearly perfect growing conditions for that species, was conspicuous. Other species present in this "mint" condition mixed prairie range included blue grama (the associate species), Junegrass, sixweeks fescue, Sandberg's bluegrass, plains bluegrass (Poa arida), and threadleaf sedge among the graminoids. It reiterated that a wet and cold spring had not been conducive to growth and productivity typical of western wheatgrass so that this co-dominant was underrepresented realtive to needle-and-thread in this photographs (and, as was explained in introduction to this section, other photographs taken during June, 2008). Forbs were very sparse on this Excellent condition class range. The most common forb was fringed sagewort followed by western or prairie spiderwort in number two spot. Other notable forbs included broadbeard beardtongue or broadbeard penstemon (Penstemon angustifolius) and scarlet globemallow.

The other range (second photograph) was also climax (Excellent range condition class) needle-and-thread--western wheatgrass mixed prairie. This pasture was on the other side of a state highway (Nebraska 20) from the range just described. Both pastures were the same range site. Grassland communities on both ranges had--for all intents and purposes was-- the species composition and structure. The only difference was that the first range described had been managed under light grazing whereas the second range was being utilized under heavy grazing. It seemed likely that both grzing intensities had been used in recent grazing seasons. If this was the situation differences in grazing intensity had not resulted in readily observable differences in species composition and range condition class (both pastures were in Excellent range condition class).

In some local areas on both of these ranges--though especially the second--the native annual grass, sixweeks fescue, was the associate species to needle-and-threan and western wheatgrass. This species combination was consistent with the observation that sixweeks fescue increased going into drought on eastern prairies (Weaver, 1954, p. 231) and following drought as the second weed stage of secondary succession on mixed prairie (Weaver and Albertson, 1956, ps. 143, 146).

Key feature of this range type- the physiogonomy of this cover type (ie. the general appearance or overall aspect of this range vegetation) that distinguished it as mixed prairie was dominance by midgrass species (needle-and-thread and western wheatgrass) with some associate species that were of low enough stature at maturity to be interpreted as shortgrasses, at least in these range environments (eg. blue grama, plains bluegrass, sixweeks grama). Blue grama has been interpreted as either a shortgrass species (on habitats where it reaches smaller adult size--including shorter height--and is co-dominant with buffalograss) or a midgrass (on habitats where its sexual shoots grow to heights of, say, two feet or even taller). The relevant physiogonomic feature on this rangeland cover type is that tallgrass species--at least as major components of range vegetation--were not present. The key or distinguishing features that defined this range type as mixed praire were 1) dominance by several species of midgrasses 2) along with shortgrass species and 3) conspicuous absence of tallgrass species. This latter characteristic was in contrast to some other rangeland cover types that were also mixed prairie yet with a prominent tallgrass component (eg. the Wheatgrass-Bluestem-Needlegrass [SRM 606] rangeland cover type covered below). Another key feature of the western wheatgrass--needle-and-thread type was absence of a warm-season dominant. This contrasted with the Wheatgrass-Bluestem-Needlegrass (SRM 606), covered below, and the Wheatgrass-Grama-Needlegrass (SRM 608) that was treated above.

Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).

105. Heavy use but not necessarily overuse- Two views of a mixed prairie range with potential natural vegetation co-dominated by needle-and-thread and western wheatgrass. Photographs presented and described in the immediately preceding two-slide set showed this climax vegetation under light grazing (first photograph) and heavy grazing (second photograph). The two photographs of this current caption presented another part of the heavily grazed range introduced immediately above. These two current photographs--the first at longer and the second at shorter or closer camera distance--presented range vegetation at outer perimeter of a sacrifice area (watering facility) where this zone of overgrazing contacted that part of the same pasture that was being heavily grazed but not necessarily being overused, yet alone overgrazed. On this most heavily grazed part of the range that was NOT in the obvious sacrifice area, cover of western wheatgrass was proportionately much greater than cover of needle-and-thread as well as on the range across the road that had been lightly grazed. Cover and density of six weeks fescue was noticeably greater under heavier grazing. Relative species composition of the other range plants was essentially the same.

Did heavier defoliation (degree of use; utilization) adjacent to the sacrifice area constitute overuse? Did it amount to overgrazing resulting from longtern overuse? Obviously there had been a shift between the two climax--two decreaser species--co-dominants. Given that western wheatgrass and needle-and-thread were of the same successional status (climax) a rational case could be made that was no change relevant to range condition class so that this criterion had not changed (ie. the heavy grazed zone outside the sacrifice area was still Excellent range conditin class). Logically this conclusion could be justified as long as needle-and-thread was still present at some realistic density, cover, general abundance, herbage yield, etc.

The morals of this lesson are: 1) there is unavoidably some degree of subjectivity and some room for value judgments, 2) management goals and conclusions are not absolute, 3) conclusions can differ rationally among rangemen, and 4) which is one of the first facts given in the first lecture in Principles of Range Management (typically the introductory course), range management is an art as well as a science.

Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).

106. Differences in use- Paired plots of threadleaf sedge (Carex filifolia) under light grazing (first--vertical-- of these photographs) and heavy grazing (second--horizontal-- of these photograaphs). The lightly grazed sedge plant was on the range that presented in the first of two photographs in the two-slide set just before before the immediately preceding two-slide (first photograph above the caption that read "At its zenith"). The heavily grazed threadleaf sedge was on the range shown in the second slide in that first set and in both photographs of the immediatley preceding set. The heavily grazed sedge cn be seen in the right midground of the first photograph of the heavily grazed range.

Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).

107. Oppostie sides of the fence- Two views of a fenceline contrast between the mixed prairie range having heavy grazing that was shown above and outside this pasture where there was no livestock grazing (and probably little if any grazing by anything else). The first photograph presented ungrazed mixed prairie to the right and heavily grazed mixed prairie on the left. The second photograph showed ungrazed grassland on the left and heavily grazed mixed prairie to the right.

Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).

108. Pocketed disturbance- Local range degradation (range retrogression) caused by plains pocket gopher (Geomys bursarius), a native fossorial (burrowing) rodent. A combination of burrowing and feeding on range forage by the plains pocket gopher was responsible for conversion of a climax needle-and-thread and western wheatgrass mixed prairie in the Central Great Plains into a weed patch, and alien (Eurasian) weeds at that. This gopher-degraded local patch (microhabitat of approximately 30-45 square yards) was on highway right of way (Nebraska 20) in contact with the first of two Excellent condition class ranges presented above having the caption, "At its zenith". Plants of needle-and-thread and western wheatgrass had been killed out and their place was now taken by cheatgrass and tumble mustard.

The first of these two slides showed the climax needle-and-thread--western wheatgrass sward in the background (posterior one-third to a short one-half of photograph) and the weed patch that replaced the Excellent condition vegetation in foreground (front half to two-thirds of photograph). The second slide featured exclusively the weed patch (climax mixed prairie degraded to a local community of Eurasian annual weeds). In this second slide most plants of tumble mustard were in full bloom while cheatgrass was in the soft-dough stage (ie. most plants were at maximum adult size; vegetation at peak standing crop). For whatever reason(s), plants of tumble mustard showed in the first photograph were much less mature (only in prebloom stage) than those in the second slide even though all of these plants where growing within a few feet of each other. Cheatgrass was at same phenological stage (soft-dough) in both of these photographs. Sixweeks fescue, the native annual grass that obviously had greater density and cover on heavier grazed portions of adjoining and proximate mixed prairie ranges (see above), was almost nonexistant on gopher-impacted habitats.

Soil churned up by pocket gophers was visible in both photographs though more so in the second. Such soil moverment was an example of pedoturbation, "mixing within a soil or sediment profile by various processes, such as animal burrowing, tree throw, frreeze-thaw cycles, etc. (Soil Science Society of America, 2001). Pedoturbation is one of many soil forming processes or, perhaps more precisely, one aspect of such a pedogenic process. Vaughan (1972, p. 154) stated that members of the pocket gopher family "are the most highly fossorial North American rodents".

Plains pocket gophers feed on both roots and shoots of range plants. Shoot material is eaten both aboveground as well as pulled from above down into the burrow (Internet Center for Wildlife Camage Management: http://icwdm.org/handbook/rodents/PocketGophers.asp). Also, pocket gopher herbovory includes consumption of and impact on range plants by covering with soil and/or dislodging from the soil. This is the same net result as mechanical cultivation of weeds (ie. smothering so as to prevent photosyntheesis and/or physical removal from soil). In this instance, gophers "cultivated" weeds instead of the climax grass crop. In this context, gophers themselves could be interpreted as "animal weeds" (= a pest or noxious species).

An objective appraisal of this pocket gopher impact would have to allow for the possiblity that disturbance to range vegetation as shown here was beneficial or neutral to the range and not automatically an adverse impact. When viewed in an ecosystem or landscape context and over ecological, especially successional, time scale it is certainly plausible that herbivory (including burrowing) by the native plains pocket gopher played important--perhaps essential--roles in structure and function of the range plant community. Clearly, this species and native range plants co-evolved. It would be naive, if not irresponsible, to assume that there is no natural and well-adapted interaction among them.

It must be underscored that plants which invaded the gopher-disturbed microsite were nonnative species brought onto North America by nonindigenous European man. Thus this zootic disturbance was by definition human- as well as rodent-induced. This local zootic disclimax was partially anthorpogenic in origin (caused to some extent by post-Columbian man). The relevant question would have to be, What would gopher-affected areas be like (what plants would populate the gopher-impacted rangeland) if white man had not carelessly introduced cheatgrass and tumble mustard? Perhaps the native annual sixweeks fescue would have vegetated gopher-denuded spots if Eurasian annual grasses and forbs were not present. Appearance of sixweeks fescue as a member of the second weed stage was described by Weaver and Albertson (1956, ps. 143, 146). Given the small size of gopher-disturbed patches it might be possible that grains of needle-and-thread or rhizomes of western wheatgrass, the dominant decreasers, would quickly repopulate such spots if these climax species did not have to compete with aggressive exotic weeds. It could be speculated as to this or that, but the answer cannot be known without controlled experimentation (ie. gopher-disturbed areas with Eurasian weeds compared to gopher-disturbed areas without these weeds, and with all other variables the same on both of these treatments).

Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).

109. "Mustard and custard"- Three mature plants of tumble mustard at peak blooom (first photograph) and two sexually immature (prebloom stage) plants of tumble mustard (foreground or in front of barb wire in second photograph). Tumble mustard is one of the worst weeds on some western ranges in the vast space from the Great Plains through parts of the Great Basin.

Tumble mustard got its common name from the fact that it is one of several annual forbs that breaks off near the soil surface and blows across the land scattering next year's generation as it "tumbles" with the almost always present wind (Whitson et al., 1992, 237) ). It is also one of several exotic weeds that has this unfortunate (from perspective of the undesirable spread of noxious alien plants) adaptation.

Pat Brady, sidekick to Roy Rodgers, had his share of colorful expressions. "Mustard and custard" was one he employed when things did not quite work out the way they should have. Even without Nelly Belle (Brady's jeep) his words transported the idea that there would be "happier trails" across the range withoug this annual invader and ts especially noxious (aggressively weedy) features like taking soil moisture that could have been used by valuable native forage grasses. Ya reckon Trigger and Buttermilk would take a nip or two off tumble mustard? No, Bullet wouldn't, but you can bet he'd hike his leg on it (off camera of course).

Sioux County, Nebraska. Late June.

110. Alien flowers- Inflorescence of tumble mustard. The cross-resembling arrangement of petals was basis of the traditional family name Cruciferae (crux, meaning cross and ferre, to bear). There are numerous crucifers across the Western Range some of which closely resemble each other (at least to the untrained eye). There are fewer of these "sorta look-alike" mustards in the Central Great Plains where these specimens were photographed.

Sioux County, Nebraska. Late June.

The Wheatgrass-Bluestem-Needlegrass (SRM 606) rangeland cover type is about driest form of Nebraska Sandhills grassland. It is a mixed prairie range type that is a transition between the more xeric wheatgrass mostly Agropyron smithii)-needlegrass (primarily Stipa comata) cover type (SRM 607), that is generally west of the Sandhills, and the mesic bluestem (especially Andropogon hallii)-prairie sandreed (Calamovilfa longifolia) cover type (SRM 602), perhaps the most common rangeland cover type of the Nebraska Sandhills, and that is best developed farther to the east. In this transition range type the dominants were (in relative order) western wheatgrass and needle-and-thread from SRM 607 and sand bluestem from SRM 602.

Key feature of this range type- This form, this range type, of mixed prairie included a dominant tallgrass species. The tallgrass growth form, represented primarily by sand bluestem, was not only a prominent but also a dominant component of this range plant community. This was in contrast to other rangeland cover types of mixed prairie that included only midgrass and shortgrass species such as the Wheatgrass-Needlegrass type ( SRM 607) and the Wheatgrass-Grama-Needlegrass type (SRM 608) covered above. Likewise, sand bluestem also added a dominant warm-season species, a dominant component that was lacking in the western wheatgrass--needle-and-thread type.

Two examples of the Wheatgrass-Bluestem-Needlegrass type (SRM 606) were presented below using two ranges separated by Nebraska Highway 20. Both were degraded to some degree. They were photographed in the first growing season after a prolonged drought (four to five year depending on interpretation of precipitation data). The first range was in high Fair range condition class; the second, in low Good condition. In the late vernal aspect of range vegetation shown invasion by Kentucky bluegrass and the annual bromes (mostly cheatgrass, but also Japanese chess) was conspicuous. Beneath canopy cover of these Eurasian invaders and needle-and-thread there was a relatively dense component of western wheatgrass, the foliar cover of which was atypically sparse due to a late spring (abnormally wet but cold) which resulted in unfavorable growing conditions for this species.

It was still early in the growing season for the warm-season dominant, sand bluestem, so that it had relatively low foliar cover being in earlier stages of phonological development. The same situation obtained for blue grama, the most important warm-season midgrass species. The range plant communities on these two ranges would be considerably different (with a corresponding difference in composition and structure, especially dominance) later in the warm-season phase of plant growth/development (ie. if the estival or autumnal aspects were shown versus the vernal aspect that was presented here).

The co-dominants of these two sample ranges were western wheatgrass and needle-and-thread with the latter having aspect dominance in this spring for reasons described immediately above. Sand bluestem was the obvious associate species. Other principal native species included blue grama, Junegrass, and sand dropseed. Forbs were limited with the most common species being smooth scouring rush or horsetail (Equisteum laevigatum). Widely scattered plants of prickly poppy (Argemone polyanthemos) presented a strinking appearance that far exceeded this species' contribution to plant cover in the range community.

111. Western edge of Nebraska Sandhills- Degraded form (Fair range condition class) of Sandhills mixed prairie of the western wheatgrass-sand bluestem-needle--and--thread type. The range cover type represented by this range is characterized by dominance of the two major cool-season midgrass species of this Central Great Plains region and one of the two major warm-season tallgrass species of this region. In addition to these domiants other major species on this range included the native perennial grass species of blue grama and Junegrass, the naturalized perennial Kentucky bluegrass, and the three annaul grass species of cheatgrass or downy brome, Japanese chess or brome, and sixweeks fescue. There were some plants of threadleaf sedge. The main forb was western ragweed, but it was not common. There were some other forb species, but these weer of little consquence.

Cherry County, Nebraska Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-60 (Wheatgrass-Bluestem-Needlegrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Nebraska Sand Hills- Sand Hills Ecoregion, 44a (Chapman et al., 2001).

112. Not the best; not the worst- Sward of the western wheatgrass-sand bluestem-needle--and--thread Sandhills mixed prairie range (Fair range condition class) presented in the immediately preceding slide. Species present in this "photo-quadrant" included western wheatgrass, needle-and-thread, blue grama, Junegrass, Kentucky bluegrass, downy brome or cheatgrass, Japanese chess or Japanese brome, and western ragweed.

Cherry County, Nebraska Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-60 (Wheatgrass-Bluestem-Needlegrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Nebraska Sand Hills- Sand Hills Ecoregion, 44a (Chapman et al., 2001).

113. Not perfect, but better- Example of Nebraska Sandhills mixed prairie of the western wheatgrass-sand bluestem-needle--and--thread range type. These two land-sweeping photographs presented physiogonomy and strucure of this grassland at a stage approaching climax stage (Good range condition class). The range presented hee was on the opposite side of Nebraska Highway 20 straight across from the Fair condition range described in the two immediately preceding photographs. This range had considerably greater species diversity than the Fair condition range. Cover of sand bluestem, the only tallgrass species with much cover or density (little bluestem was represented by a few, widely scattered individuals) was conspicuously greater than on the Fair condition range. (Sand bluestem was prominent in center foreground of both photographs, especially the second one.) Likewise, cover and density of needle-and-thread and Junegrass were considerably greater on the Good condition class range, but general and relative abundances of western wheatgrass and blue grama were about the same on both pastures. There was very little cover of Kentucky bluegrass, an alien though naturalized invader, on this Good condition range. There was much less cover of the naturalized exotic bromes on the Good condition range, but general abundance of sixweeks fescue was about the same on both of these pastures.

This Good condition range had more forbs but less forb cover than the Fair condition range. The major range forb on this Good pasture was common horsetail (Equisteum arvense). Western ragweed was the second most common forb, but it had less cover than on the Fair condition range. Prickly poppy (Argemone polyanthemos) was more common on the higher condition class range, but this biennial was far from common.

Details of the sward of this Good condition range was presented in the next photograph.

Cherry County, Nebraska Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-60 (Wheatgrass-Bluestem-Needlegrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Nebraska Sand Hills- Sand Hills Ecoregion, 44a (Chapman et al., 2001).

114. More like it- Sward of Nebraska Sandhills mixed prairie of the western wheatgrass-sand bluestem-needle--and--thread range type. This was a "photo-plot" of the Good condition class range featured in the two immediately preceding photographs. Sand bluestem (the largest, tallest grass in center foreground) was conspicuous. Needle-and-thread, one of the regional cool-season dominants, was the most abundant species in the sample of range vegetation presented here. Other species visible in this slide included western wheatgrass, blue grama, cheatgrass (very limited) and the two forbs, common horsetail and western ragweed.

Cherry County, Nebraska Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-60 (Wheatgrass-Bluestem-Needlegrass). SRM 607 (Wheatgrass-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Nebraska Sand Hills- Sand Hills Ecoregion, 44a (Chapman et al., 2001).

115. Mark of a good sandhills steward- Sandhills in the Great Plains are one of the wind-sensitive of all range ecosystems in North America. The beauty and productivity of these marvelous grassland ranges belies their fragility to wind-caused soil erosion. A commonsense and ideal practice to prevent wind erosion on ranges in the Nebraska Sandhills is the lashing together of discarded automotive tires (often with the universal standby of used baling wire) around utility poles within cattle-rubbing distance. Range animals, especially bovids like cattle and buffalo, love to rub on poles and tree trunks (both of which are scarce on this rangeland). This rubbing or bovine form of scratching is more common in spring when animals are shedding their winter coats or when they are heavily infested with lice. The though yet vulnerable range plants would be trampled out around posts, power poles, cottonwood snags, etc. where animals habitually rub. Loss of plant cover causes a "break" in the sward and a resulting "opening" on the land awaiting soil removal by eolian forces.

Some faithful stewards like power company linesmen responsible for this power corridor or the owner of this range took the appropriate preventive action to protect this valuable yet sensitive grazing land from what could quickly become severe wind erosion. A well-earned tip of the hat to the hard workers who did their part in the wise use management of this grassland.

Cherry County, Nebraska Late June (early estival aspect).

Foothills Bluegrass Mixed Prairie: an ambiguous range type- Developing in the foothills of the Sourhern Rocky Mountains (Laramie Mountains) and situated at margins of needle & thread-blue grama-western wheatgrass mixed prairie (Kuchler 57), blue grama-buffalograss mixed prairie (Kuchler 58), and ponderosa pine-Douglas-fir montane forest (Kuchler 17) are relatively small, isolated grasslands of mid-height grasses, especially the larger species most notably Canby's bluegrass (Poa canbyi) and big bluegrass (P. ampla). Presented in this section was an example of these foothill grasslands some of which were dominated by larger bluegrasses and that appeared as a form of mixed prairie. These granitic (generally igneous parent material)-based range sites (Igneous and Shallow Igneous, Foothills and Mountains Southeast) were described by the Natural Resources Conservation Service (1998) as having bluebunch wheatgrass (Agropyron spicatum) as the most abundant, if not the dominant, range plant species. Percent composition of bluebunch wheatgrass was shown for different soil series (Natural Resources Conservation Service, 1998, ps. 280-309 passim) at values from 35% down to 15%. Slimstem muhly (Muhlenbergia filiculmis) and threetip sagebrush (Artemisia tripartita= A. trifida) were listed as major species of the potential plant community (Natural Resources Conservation Service, 1998). There was no reference to Canby's or big bluegrass, period.

This description differed drastically from the units of potential natural vegetation mapped and described by Kuchler (1964, 1966) as given in the preceding paragraph (see especially Kuchler, 1964, units 64 and 66). Mapping and describing a bluebunch wheatgrass-dominated grassland (more like an eastern island of the Palouse Prairie) was also inconsistent with Society for Range Management (SRM) rangeland types described in Shiflet (1994), specifically SRM 606, 607, 609 that represented range vegetation on this region. Instead the NRCS (1998) categorizations were essentially those of SRM rangeland cover types (SRM 302, 303, 304, or some combinations thereof) given for the Northern Rocky Mountains province (Shiflet, 1994, ps. 27-29). This was true in particular with regard to range plant species dominating deteriorated ranges described as dominated by bluebunch wheatgrass.

The range vegetation shown and described in this section (a Rogert-Rock outcrop; Shallow Igneous range site) did not fit the range plant community descriptions of the Natural Resources Conservation Service (1998), for either climax or stages of range degradation. Nor did ecological site descriptions (Natural Resources Conservation Service, 2006) match this vegetation. Neither did this bluegrass-dominated e featured range plant communities described in published rangeland cover types (Shiflet, 1994). Rather, this range vegetation was dominated overwhelmingly by various bluegrassees, especially Canby's bluegrass (P. canbyi), the dominant species, and the similar big bluegrass (P. ampla). Grass species from other conterminous mixed prairie types (notably blue grama;, to lesser extent, western wheatgrass; and with less cover yet, needle-and-thread, for example) were present but quite limited. Other bluegrass species included (and in relative order based on general abundance, cover, etc.) Sandberg bluegrass (P. secunda), nodding bluegrass (P. reflexa), and-though restricted to small and more mesic depression-a Poa species with an immature panicle that suggested--but could not be positively identified as-- fowl bluegrass (P. palustris). Mutton bluegerass (Poa fendleriana) was present growing on an adjacent area, but was not found on the range that was photographed and presented here.

Almost all green grass plants were Poa species with mature (or nearly so) spikelets. The range vegetation presented here was composed in overwhelmingly quantity (based on general cover, density, aspect abundance) of bluegrasses, especially Canby bluegrass, the single dominant species. Again, blue grama, western wheatgrass, and needle-thread (the zonal climax dominants) were present, but ranking well behind Canby, big, and Sandberg bluegrasses. Junegrass was present at relative abundance approaching that of trace quantity. Also present at edges of the gravely environment of this foothill bluegrass range was sheep fescue (Festuca ovina var. rybergii) and a trace of what appeared to be King's spikefescue (Leucopoa kingii). Also present (and at typically high densities) were threetip sagebrush (A. tripartita subsp. rupicola) and fringed sagewort (Artemisia frigida) as well as the conspicuous forbs, miner's candle (Cryptantha virgata= Oreocarya virgata) of the Boraganaceae and tufted fleabane (Erigerion caespitosus). Another common forb on this range was the umbel, whidkbroom parsley (Harbouria trachypleura).

The range site descriptions provided in the Soil Survey for the Albany County, Wyoming area (Natural Resources Conservation Service, 1998) simply put were not appropriate for--they did not fit--this range vegetation in any successional stage. Ecological site descriptions (Natural Resources Conservation Service, 2006) did not even list Canby's bluegrass. It was possible that Sandberg's bluegrass was used as a generic name that included Canby's and big bluegrasses. The NRCS Plant Guide for Sandberg bluegrass interpreted this as a Sandberg bluegrass complex that included big bluegrass, Canby's bluegrass, and several recognized Poa species. This was consistent with the treatment in Barkworth et al. (2007, ps. 586-688) wherein the former P. canbyi was reintepreted as a "smooth, larger" ecotype of P. secunda subsp. secunda. The continent-wide treatment by Barkworth et al. (2997) contrasted with the manual for Wyoming (Skinner et al., 1999, ps. 78-82) in which the species P. canbyi was retained and distinguished clearly from P. secunda subsp. secunda. Mr. Bob Mountain, U.S. Forest Service, explained (personal communication) to this author that throughout this plains and mountains complex of range types and sites there were many Poa species yet Forest Service range workers on the Medicine Bow National Forest, which neighbored with the range described below, generally tried to distinguish among these species. For example, in doing range vegetation inventories Forest Service rangemen listed separately, to the extent practicable, such species as P. canbyi, P. ampla, P. fendleriana, P. secunda (= P. sandbergii), P. nervosa, P. palustris, and P. reflexa. Lumping several bluegrass species under a generic Sandberg's bluegrass --if indeed such was the case for Natural Resources Conservation Service (1998, 2006) range site descriptions--could be overly simplistic and lead to extreme confusion. Even if Canby's bluegrass is an ecotype of P. secunda subsp. secunda it is different from the ecotype of P. secunda subsp. secunda that is Sandberg's bluegrass. Both of these species, forms, ecotypes, etc. were present on the rangeland shown and presented below. If Sandberg's bluegrass is is an obvious increaser on this range site, it is still possible (erhaps even highly probable) that the larger species, ecotypes, or whatever like Canby's and big bluegrass are likely to be decreasers.

Whatever the explanation, neither climax or any of the published states of range retrogression (Natural Resources Conservation Service, 1998, p. 113; Natural Resources Conservation Service, 2006) described, at least not adequately, the foothills bluegrass mixed prairie that was shown and described in the following section.

Contrary to published range site descriptions and rangeland productivity tables (Natural Resources Conservation Service, 1998) the bluegrass-foothills grassland was not an island of the Palouse Prairie. Nor again (as explained above) was this range vegetation, which was most likely at some higher successional state (at least subclimax) covered in any of the Kuchler (1964, 1966) units of potential natural vegetation or in rangeland cover types (Shiflet, 1994). In fact, the most telling evidence that something was wrong or incomplete in published descriptions of this climax.or potential natural vegetation was the glaring contraction between Kuchler (1964, 1966) and Natural Resources Conservation Service (1998) designations. The Natural Resources Conservation Service (1998, p. 113) described this range vegetation as, in effect, an eastern extension of Palouse Prairie (bluebunch wheatgrass-dominated with various other wheatgrasses and Idaho dfescue) whereas Kuchler (1964, 1966) mapped it as shortgrass mixed prairie (grama-buffalograss). by were in extreme conflict. In the Kuchler (1966) map version provided in Garrison et al. (1977) this potential natural vegetation was mapped as unit 58 (Grama-Buffalograss; Bouteloua-Buchloe), but based on the Natural Resources Conservation Service (1998) range site description it would be Kuchler (1966) unit 43 (Fescue-Wheatgrass; Festuca-Agropyron) or unit 44 (Wheatgrass-Bluegrass; Agropyron-Poa). Obviously this was an extreme conflict where both cannot be correct. In this author's view, neither was correct.

Prof. J. Daniel Rodgers, University of Wyoming, explained to this author (personal communiction) that Canby's bluegrass was a common dominant species, especially above the foothills and up to the pine forests, along the Rocky Mountain Front Range and neighboring areas. Caby's bluegrass is especially common and dominant on gravelly, granitic soils such as those derived from Sherman granite. On such range sites Canby's bluegrass is frequently to typically associated with threetip sagebrush. Dr. Rodgers further explained that, as of that time, there was not a published, readily available description of range vegetation for this area. In essence there is not a published description of the foothill bluegrass or Canby bluegrass range type, at least there is not a readily accessible description at time of this writing.

Irrespective of whether Canby's bluegrass is a distinct species or an ecotype of Sandberg's bluegrass or is a decreaser or an increaser, and thus the foothills bluegrass mixed prairie be climax (potential natural) vegetation or a higher seral stage, the indisputable fact remained that the Canby bluegrass-threetip sagebrush range plant community described below was representative of typical ranges throughout this area.

Photographs were taken in early summer (late June) following an abnormal year (an unusually moist to wet yet cold spring. In this general locality grasses like western wheatgrass and bluebunch wheatgrass took several weeks longer to reach advanced phenological stages. In fact, western wheatgrass generally did not advance to maturity as in typical years. Hence, the photographed range vegetation was atypical with some species such as bluebunch wheatgrass under-represented (if present it was in earlier stages of phenology). That noted, it was emphasized that this photographer did not observe bluebunch wheatgrass even at earlier stages of growth. If this species was present--as seemed plausable given its documented occurrence in this area (Skinner et al., 1999, p. 155)-- it was as a minor component based on cover, density, and general abundance. Even western wheatgrass growing on this range was more common on low-lying, more mesic microsites (see below) than on other local habitats of this gravelly, shallow edaphic environment.

Relatively high cover of threetip sagebrush and fringed sagewort in the range plant community presented below was consistent with brief range site descriptions by the Natural Resource Conservation Service (1998). Occurrence of fringed sagewort fit descriptions of all the above cited SRM rangeland cover types (SRM 302, 303, 304, 606, 607, 609) so as to be of limited value for distinguishing among several range types including those of contiguous cover types. Rather it was presence of threetip sagebrush that was of telling importance for this range type.

This range vegetation was clearly dominated by Canby bluegrass with others like big and Sandberg's bluegrass as associate species. Given the conditions and general situation described above it seemed likely that the range vegetation featured here was in some stage of retrogression. The extent of range deteioration (departure ferom whatever the climax was) could not be determined though it likely was not lower on the sere than subclimax. As stressed above, these species were not listed as being component species in any of the published range site or rangeland cover type descriptions in any state of range degradation. Thorough description of range sites and types would require inclusion of large species of native bluegrasses which made up most of the range vegetation at a stage in development of the natural plant community.

This foothill mixed prairie vegetation was featured immediately below. It was presented because it was it is a widespread range plant community in what appeared as a broad ecotone between Great Plains grassland and Rocky Mountains forests, scrublands, and parks. Detailed discussion, including that of the relevant literature, was provided to point out emphatically that this range vegetation was not described in readily available material (if at all) and certainly not to the extent of most other units of range vegetation. Furthermore, much of the existing descriptions are contradictory, conflicting, and confusing. This was due to such things as inconsistency among authorities and ambiguity in plant names. Hopefully somebody will recognize this glaring omission and write descriptions of this and associated rangeland cover types as well as more precise reports of range sites.

116. Foothills range in the Laramie Range- Canby's (Canby) bluegrass-dominated mixed prairie with Wyoming threetip sagebrush (Artemisia tripartita subsp. rupicola = A. trifida) the associate plant species on the Front Range of the Rocky Mountains. Other important range plants included blue grama, Sandberg bluegrass (readily distinguishable from other bluegrasses by smaller size and more advanced maturity or phenological development); fringed or plains sagewort (A. frigida); and small, isolated colonies of western wheatgrass in local depressions. Junegrass was present as sparsely scattered individuals. There were also some scattered plants of what appeared to be big bluegrass (Poa ampla). These plants were partly distinguishable from P. canbyi by their wider leaf blades, but identification was not completely positive because plants that were thought to be big bluegrass had not yet produced panicles. There were some plants that may have been King's spikefescue (Leucopoa kingii), but these were not in flower and could not be identified either. There were a few forb species present including tufted fleabane (Erigeron caespitosus), whiskbroom parsley (Harbouria trachypleura), and miner's candle (Cryptantha virgata= Oreocarya virgata). Individual plants of these species were conspicuous in a "sea of grass shoots", but none of them contributed substantial cover (relative or absolute) or were of notable density or herbage production.

Needle-and-thread, which was the "super-abundant"dominant of other rangeland cover types in the mixed prairie of adjoining and lower elevation landscapes, was "conspicuous by its absence" in the foothill range vegetation described in this section. Likewise, bluebunch wheatgrass, reportedly the climax dominant of this range site, appeared to be absent ("totally missing") from this range. Unusually cold and wet conditions in late winter throughout spring could have delayed development of any bluebunch wheatgrass that was present, but this worker did not observe any plant material--either dead, decaying tissue from the preceding year (eg. naked spikes, weathered leaves or culms) or young, energing shoots of the current year--that evenly faintly resembled this species. Likewise, this observer did not notice any slimstem muhly, the other reported (Natural Rsesouces Conservation Service, 1998) major decreaser grass for this range site. Slimstem muhly is especially well-adapted to shallow granitic soils (Skinner et al., 1999, p. 202) like those on this range. It was hihgly likely that both bluebunch wheatgrass and slimstem muhly were on this range at trace to slight amounts and that past overgrazing had eliminated both of these perennial decreasers. Since earliest days of occupation by whiteman this area was heavily grazed by livestock--as beasts of transport for all sorts of travelers and commerical ventures (including the first transcontentintal railroad) as well as commodities produced by sheepmen and cattlemen, alike.

The unique geologic features on this rangeland combined with the "ambiguous" range plant community as detailed above resulted in an intriguing and unusually romatic "rangescape" The geologic formation featured here was the Sherman Mountains (composed of Sherman Granite), remnants of the Sherman batholith, in the larger Laramie Range (Laramie Uplift). The Laramie Range is one of two prongs or forks of the Front Range in this area, the Medicine Bow Range being the other prong. Both of these geologic prongs or forks are in turn part of the eastern slope (the front edge) of the Rocky Mountains known as the Front Range (Lageson and Spearing, 1988, ps. 23-26; Edwards and Frost, 2000). The mountain building, the process of orogeny, by which the Rocky Mountains were formed takes its name from the Laramie Range: Laramide Orogeny. This geologic event took place during the Late Creatceous Epoch rougly 80 to 70 million up to 55 to 35 million years before present. Northern and southern portions of Laramie Range are comprised of two kinds or forms of bedrock. The bedrock of the southern part (the parent material of soils in this area) is Sherman Granite formed in the Late Precambrian Geologic Time and that crystalized to its present state about 1.4 billion years before present during the early Mesoproterozoic Geologic Eon (Lageson and Spearing, 1988, ps. 25-26; Edwards and Frost, 2000).

The landscape shown here was on the so-called Gangplank, a large alluvian fan out of the Laramie Range which, being an uplifted gradual slope, served as an easier overland route (including for the transcontentintal railroaad) across this northern part of the Front Range. Use as a trade route unavoidably resulted in heavy grazing by livestock which could have resulted in range degradation and replacement of species like bluebunch wheatgrass and slimstem muhly by species like Cnby's bluegrass and blue grama. In current times knowledgable local folks make reference to bluegrass, blue grama, and "short sagebrush" but not to other species. Whatever was or might be, this widespread range vegetation was clearly 1) bluegrass-dominated mixed prairie that was 2) not included in readily accessible descriptions of range types and range sites.

Albany County, Wyoming. Late June; late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). Range site: Shallow Igneous, 15-19 inch precipitation, Foothills and Mountains Southeast (Natural Resources Conservation Service, 1998, 2006). Southern Rockies- Foothill Shrublands Ecoregion, 21d ( Chapman et al., 2003).

117. Sherman Mountains mixed prairie- On the "rangescape" of the Sherman Mountains a bluegrass-dominated mixed prairie of bunchgrass form (phusiogonomy) had developed (perhaps it had retrogressed from a higher successional stage). Canby bluegrass was the overwhelming dominant (based on cover--both foliar and basal--as well as density and, especially, biomass) with Wyoming threetip sagebrush the associate species. The other major (common) range species were blue grama, Sandberg's bluegrass, western wheatgrass (limited to local depressions), fringed or plains sagewort, Junegrass, and big bluegrass. The latter two species were present as individual plants or in small, isolated patches. Big bluegrass was tentatively distinguished from plants of Canby's bluegrass that was at peak inflorescence (grain in hard-dough stage). Plants that were thought to be big bluegrass had conspicuously wider leaves and a deeper-green color than Canby's bluegrass. Sandberg's bluegrass had already fully matured and was entering dormancy. Forbs were incidental and included tufted fleabane, whiskbroom parsley, and miner's candle.

Needle-and-thread, the regional dominant of Central Great Plains grasslands (and extremely abundant in this year), was absent--completely missing--from this range type. Such was also the case for bluebunch wheatgrass, the reported (Natural Resources Conservation Service, 1998, 2006)) climax, decreaser, dominant for this range site. This observer doubted that either of these grasses was a major species on the shallow, droughty soil of this fairly widespread range type. Slimstem muhly was the other dominant decreaser grass on this range site according to descriptions by the Natural Resources Conservation Service (1998, 2006) and this species also was not a major component of the range plant community on this range. Overgrazing as far back as the frontier era may have contributed to elimination of these two designated decreasers from this range. Local grass-growing conditions preceding these photographs of current-season vegetative growth was another partial explanation for the obvious species composition of this range plant community. An ususually cold and wet spring had hampered development of late-season species like bluebunch wheatgrass throughout the Laramie Range prior to time of these photographs (Mr. Bob Mountain, M edicine Bow National Forest, personal communication). This situation could not have explained absence of previous year's plant material of bluebunch wheatgrss or slimstem muhly that should have been present if these species grew on this range. Lack of such herbaceous reside (at least in any meaningful amounts) substantiated absence of these species in the vegetation of this range.

The rock outcrops of smaller boulders on this range were of Sherman Granite, a coarse-grained igneous rock of the early Mesoproterozoic Geologic Eon (about 1.4 billion years before present), that make up much of the Sherman Batholith. A batholith is a large geologic mass of igneous intrusive (plutonic) rock derived from magma that cools and ascends to the land surface. Frost et al.(2000) concluded that the Sherman Batholith was most likely caused by partial melting of rocks derived from Earth's mantle.

Albany County, Wyoming. Late June; late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). Range site: Shallow Igneous, 15-19 inch precipitation, Foothills and Mountains Southeast (Natural Resources Conservation Service, 1998, 2006). Southern Rockies- Foothill Shrublands Ecoregion, 21d ( Chapman et al., 2003).

118. Physiogonomy and structure of foothill mixed prairie- A bunchgrass form of mixed prairie dominated by Canby's bluegrass (with Wyoming threetip sagebrush as associate) on the Sherman Mountains of the Laramie Range. This "photo-plot" was taken at camera focal length to feature the physiogonomy and architecture (structure as to layers of vegetation). Other abundant (based on apparent density, cover, and standing crop) plant species included blue grama, western wheatgrass (localized dense colonies limited to small depressions), Sandberg bluegrass, fringed or plains sagewort, Junegrass, and big bluegrass. Forbs were incidental (at least in the spring society) though conspicuous. These included tufted fleabane, miner's candle, and whiskbroom parsley.

This range plant community was that of late spring-early summer in a year of atypically wet and cold conditions commencing in late winter. Mr. Bob Mountain, Medicine Bow National Forest, explained to this author (personal commjnication) that weather conditions earlier in the plant-growing season had delayed development of range plants, especially at higher elevations. This was particularily pronounced in certain species of grasses including bluebunch wheatgrass. It was plausible that bluebunch wheatgrass and slimstem muhly, the two species listed as decreaser dominants in descriptions of this (and similar) range sites (Natural Resources Conservation Service, 1998, 2006), had much lower cover and biomaass in this area so as to be under-represented in this range vegetation. That would not, however, explain the lack of dead and weathered plant material of bluebunch wheatgrass and slimstem muhly that would have persisted from the previous year if these two species grew on this range. The only logical concluisions were that 1) this range was in some state of departure from a bluebunch wheatgrass-dominated climax or 2) bluebunch wheatgrass is not the potential dominant of this range site represented by the existing vegetation.

The range plant community shown here was that of the later vernal society. If other major species such as bluebunch wheatgrass were present on this range--and this rangeman certainly did not find them--they would have formed a later-season society (ie. they would not likely have been at sexually reproductive stages at this point even in a year of more typical rowing conditions). Grassland dominated by bluegrass (especially Canby's and big bluegrass) and "short sagebrush" was the range vegetation that local people in the coffee shops described for this locality to the aurthor. That was the range plant community presented in this slide.

Sherman Granite, a distinctive coarse-grained hornblende granite, comprises a major part of the Sherman batholith of the Laramie Range. Gravel derived in large part from Sherman Granite can cover up to approximately half of the surface of certain soils such as on the Rogert-rock Outcrop unit of this rangeland (Natural Resources Conservtion Service, 1998). This gravel was visible on the land surface in this photograph as well as several other slides of this range vegetation presented below. Composition of Sherman Granite was provided by Edwards and Frost (2000) and Frost et al. (2000).

Albany County, Wyoming. Late June; late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). Range site: Shallow Igneous, 15-19 inch precipitation, Foothills and Mountains Southeast (Natural Resources Conservation Service, 1998, 2006). Southern Rockies- Foothill Shrublands Ecoregion, 21d ( Chapman et al., 2003).

119. Species composition of a foothill mixed prairie- Canby's bluegrass-dominated a bluegrass mixed prairie at edge of the Front Range and Central Great Plains. Wyoming threetip sagebrush was the associate species. Other important range plants included Wyoming threetip sagebrush, blue grama, western wheatgrass (in slight depressions that afforded a more mesic microhabitat), Sandberg bluegrass, fringed or plains sagewort, and big bluegrass. The latter was tentatively identified only, because plants that appeared to be big bluegrass had not yet produced inflorescences and this author being "a stranger to these parts" could not identify them from vegetative characteristics. A wider leaf and deeper green-color separated them from plants of Canby's bluegrass, this latter of which was unquestionably identified from spikelet features (shown below).

Successional status of this range vegetation was not known. The range site description (Natural Resources Conservation Service, 1998; 2006) described the climax vegetation as being dominated by bluebunch wheatgrass slimstem muhly, and threetip sagebrush with Sandberg bluegrass and threestem sagebrush increasing under range retrogression. This author did not find any bluebunch wheatgrass on this range, but it had been a belated spring with cold,wet conditions from late winter until the present early summer so that some species like bluebunch wheatgrass were "far behind schedule" while residual herbage was highly weathered making identification of dead plant material difficult to impossible for all but local folks familar with the species at all stages of phenology and decomposition. It was also possible that Canby's bluegrass comprises most of the vernal society of this mixead prairie and later-maturing species would make up estival or autumnal societies. Nonetheless, Canby's bluegrass was dominant, even based on examination of decayed-weathered herbage. Bluebunch wheatgrass was a minor component of this range plant community at best.

The question with regard to successional state--hence, range condition class--of this range vegetation hinged on the grazong response of Canby's bluegrass. If it is an increaser like Sandberg's bluegrass this range was at substantial departure from climax (probably in Fair range condition class). If, on the other hand, Canby's bluegrass is a natural dominant (decreaser) this range plant community would rate substantially higher, perhaps being at subclimax stage. Wyoming threetip sagebrush is an increaser and its presence at high levels of abundance (relative cover) strongly suggested some degree of range degradation, again possibly Fair to low Good condition class.

Regardless of the ecological condition of this range it was representative of much of the rangeland in this area, and was presented as such.

Albany County, Wyoming. Late June; late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). Range site: Shallow Igneous, 15-19 inch precipitation, Foothills and Mountains Southeast (Natural Resources Conservation Service, 1998, 2006). Southern Rockies- Foothill Shrublands Ecoregion, 21d ( Chapman et al., 2003).

120. Stand of Canby's bluegrass- Local "photo-sample" of the population of Canby's bluegrass that dominated a bunchgrass mixed prairie in the foothills of the Laramie Range. Wyoming threetip sagebrush was the associate range plant on this rangeland.

Sherman Granite, especially conspicuous in this photograph, was the primary parent material of this soil (Rogert-Rock Outcrop). Readers wishing more details regarding Sherman Granite were referred to the report by Frost et al. (1999).

Albany County, Wyoming. Late June; late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). Range site: Shallow Igneous, 15-19 inch precipitation, Foothills and Mountains Southeast (Natural Resources Conservation Service, 1998, 2006). Southern Rockies- Foothill Shrublands Ecoregion, 21d ( Chapman et al., 2003).

121. Laramie Range mixed prairie- A bunchgrass form of mixed prairie dominated by Canby's bluegrass and Wyoming threetip sagebrush had developed on s shallow soil (Rogert-Rock Outcrop) adorned by large rocks (small boulders) of Sherman Granite. Sandberg's bluegrass was the secon most abundant grass. It was readily distinguished from Canby's bluegrass by smaller size and phenological stage approaching senescence. Tufted fleabane and miner's candle were two forb species present in the "photo-quadrants" shown here. There were also some plants of fringed or plains sagewort. Sherman Granite provides a harsh habitat for various speecies of lichen that decorate the already colorful rocks of this range type. Lichen are part of the range vegetation even though this mutualistic relationship between fungus and algae does not constitute a vascular plant.

General absence of shortgrass species other than the notable blue grama denoted this as a midgrass mixed prairie. This grassland had the physiogonomy, general height, and a species composition with an obvious affinity of regional Great Plains grassland such that this was mixed prairie. It was not, however, mixed prairie in the structural feature of having prominent layers of shortgrass and/or tallgrass species along with that of the midgrass.

Albany County, Wyoming. Late June; late vernal to early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). Range site: Shallow Igneous, 15-19 inch precipitation, Foothills and Mountains Southeast (Natural Resources Conservation Service, 1998, 2006). Southern Rockies- Foothill Shrublands Ecoregion, 21d ( Chapman et al., 2003).

122. Mixed prairie at the farthest reaches of its domain- Sward of a mixed prairie of the predominant bunchgrass form at the extreme western margin of the Great Plains just below the foothills of the Front Range. This local species-rich stand was dominated by Canby's bluegrass "assisted" with an array of other rmajor grasses including big bluegrass, Sandberg's bluegrass, sheep fescue, sixweek's fescue, western wheatgrass, and blue grama.. Cheatgrass or downy brome and crested wheatgrass were minor grass species, but their presence was evidence of the naturalization of these two introduced Eurasian species. There were no forbs or shrubs in this range plant community.

This range vegetation was lower in elevation though in close proximity to the foothill form of mixed prairie dominated by Canby's bluegrass and Wyoming threetip sagebrush described immediately above. The range environment of this exclusively grass-comprised plant community with deeper, more mesic soil was much less harsh than that of the bluegrass-threetip sagebrush community on the foothill range in the Sherman Mountains. Dominance of both range plant communities by Canby's bluegrass and presence of other grass species "shared in common" was evidence of the vegetational affinity of these two forms of midgrass mixed prairie.

Laramie County, Wyoming. Late June; early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). High Plains- Moderate Relief Plains Ecoregion, 25c ( Chapman et al., 2003).

123. Cool-season mixed prairie- At the western boundary of the Great Plains just below the foothills of the Front Range a mixed prairie had developed that was made up almost exclusively of cool-season grasses. Sheep fescue (Festuca ovina var. rydbergii or, perhaps, F. brachyphylla subsp. saximontana=F. saximontana= F. brachyphylla) was the overwhelming dominant, but Canby's bluegrass, Sandberg's bluegrass, and western wheatgrass were also well-represented in this local stand from which forbs and shrubs were absent. Also more or less absent were naturalized introduced species like cheatgrass and crested wheatgrass. This range vegetation--the range ecosystem generally--had a remarkable rate of herbage (biomass) productivity, but species richness was noticably less than of most other range plant communities in this general area.

This was a more mesic form of mixed prairie than the mixed prairie at higher elevtions in the foothills of the Front Range to which a close affinity obviously existed in both close proximity and the commonality of Canby's bluegrass. This was predominately a midgrass mixed prairie with no tallgrass species while the shortgrass element was limited to such species as Sandberg's bluegrass and blue grama, of which no plants representing these two species were in this local stand.

Laramie County, Wyoming. Late June; early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). High Plains- Moderate Relief Plains Ecoregion, 25c ( Chapman et al., 2003).

124. Standing tall- Local stand of foothills mixed prairie consisting of Canby's bluegrass (overall dominant), sheep fescue, and western wheatgrass. The lattter of these species was abnormally under-developed for this time of year due to a prolongued cold yet wet late winter through to present. An example of a stunted western wheatgrass plant was in lower left corner. On much of the habitat of this foothills form of mixed prairie western wheatgrass forms plants that are much smaller than typical and which appear almost cespitose in spite of the usual creeping rhizomes of this species. These upland, often gravelly, environments are marginal for this more mesic of the major midgrasses.

Festucoid grasses clearly predominate at latitudes this far north.

Laramie County, Wyoming. Late June; early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). No appropriate units given in Kuchler (1964, 1966) or Society for Range Management (Shiflet, 1994). High Plains- Moderate Relief Plains Ecoregion, 25c ( Chapman et al., 2003).

125. Canby's bluegrass (Poa canbyi)- The taxon represented by these specimens is either distinct species (Poa canbyi) or a larger-growing ecotype of P. secunda subsp. secunda.The latter interpretation was used in the official, authoritative Flora of North America (Barkworth, 2007, ps. 586-588) whereas recognition of P. canbyi is the traditional treatment that was still used in Grasses of Wyoming, the state grass manual, (Skinner et al., 1999, p.78-81, 82) and, which according to Hitchcock and Chase (1951, p. 938), traced back to 1906.

On initial sighting of this plant on the range one's first impression is something like , "Schzam! Sandberg's bluegrass grown under irrigation, fertilization, and on auxins". In other words, individuals of this taxon appear as "giant Sandberg's bluegrass" or "Sandberg's bluegrass except its too big". Canby bluegrass reaches heights roughly twice those of Sandberg bluegrass (Skinner et al., 1999, ps. 78, 97). Whatever the most precise name and taxonomic interpretation, Canby's bluegrass is both widespread in the northern Front Range and different morphologically from anything else. The larger size of Canby's bluegrass led to selection and release by the Soil Conservation Service Plant Materials Center and Washington and Idaho Agricultural Experiment Stations of the cultivar, Canbar.

Albany County, Wyoming. Late June; grain in hard-dough stage.

.

126. Panicle of Canby's bluegrass- Panicles of Canby's bluegrass vary from narrow to relatively wide and from compact to open (Hitchcock and Chase, 1951, p. 134; Skinner et al., 1999, p. 81). They are generally heavy grain-bearing inflorescences. These examples were typical, at least the most commonly morphological form in those found growing on this range.

Albany County, Wyoming. Late June; grain in hard-dough stage.

127. Spikelets of Canby's bluegrass- Two closer-in views of parts of Canby's bluegrass panicles showing greater detail of spikelets. Areas of darker coloration (pigmentation) on glumes and, especially, lemmas and paleas is a common feature of this species (Skinner et al., 1999, p. 82). These spikelets were somewhat weathered so that such pigmentation had faded and was less prominent than on younger spikelets.

Albany County, Wyoming. Late June; grain in grain-ripe stage.

128. Stand of sheep fescue (Festuca ovina var. rydbergii= F. saximontana=F. brachyphylla subsp. saximontana)- One of the larger, ranker-growing grasses on the mixed prairie of the Front Range of the Central Rocky Mountains was sheep fescue for which the scientific name Festuca ovina var. rydbergii was used in Grasses of Wyoming (Skinner et al., 1999, p. 66, 68). This author-photographer did not encounter this species as other than a local dominant. It was not a widespread dominant species like Canby's bluegrass though it was a more abundant than Junegrass. Clements (1936, p. 258) interpreted Festuca ovina as oe of eight perdominants, widespread dominants that bind associations together into climaxes or, the synonym, formations) (Clements, 1936, ps. 258, 271). Some of the other perdominants that bound the five grassland associations into the were needle-and-thread, western wheatgrass, blue grama, sand dropseed, and Junegrasss (Clements, 1936, p. 258). However, Clements (1920) used F. ovina as an "umbrella species" to include the widespread F. idahoensis. This usage was consistent with the taxonomy and nomenclature of that time as, for example, in Coulter and Nelson (1909, p. 75) and as explained in Barkworth et al. (2007, p. 422).

The most recent and presumedly most authoritative (though not necessarily synonymous with most taxonomically correct) treatment of F.ovina was that in Barkworth et al. (2007, ps. 428-432) in which F. ovina was was restricted to a species introduced into North America from Eurasia so that it was necessary to "transplant" all native forms, variants, etc. previously included with F. ovina into other Festuca species and subspecies. Into which of these one or more species and/or subspecies F. ovina var. rydbergii belongs was not explained in Barkworth et al. (2007, p. 422). If F. ovina var. rydbergii was "transplanted" according to the taxonomic organization in Flora of North America it seemed that F. saximontana or F. brachyphylla were the most likely candidates. Or perhaps the older taxon of F. brachyphylla subsp. saximontana was more likely to be the correct taxon for F. ovina var. rydbergii. Hitchcock and Chase (1951, p. 74) showed F. saximontana as an earlier binominal for F. ovina. Kaul et al. (2006, p.676) used F. saximontana for specimens in the far western Nebraska Panhandle that had previously been identified as (Festuca ovina var. rydbergi, but Skinner et al. (1999, p. 67-68) retained (Festuca ovina var. rydbergi for specimens and plants on Wyoming range up to subalpine elevations.

Whatever the most nearly scientifically correct scientific name, this is a large fescue of one kind or another that was locally dominant over foothills mixed prairie.

Laramie County, Wyoming. Late June; grain-shatter stage.

129. Sheep fescue or, less commonly, Rocky Mountain fescue (Festuca ovina var rydbergii=F. brachyphylla subsp. saximontana=F. saximontana or F. brachyphylla, ?, or whatever)-Examples of the robust fescue (whatever the species, subspecies) that was a local dominant on mixed prairie in the foothills of the Front Range, a transition zone between Great Plains grassland and Rocky Mountain forests and parks.

Laramie County, Wyoming. Late June; hard-dough to grain-ripe phenological stages.

130. Panicle and spikelets of sheep fescue- Flower cluster and its fundamental units, spikelets, of some large and robust, Festuca taxon that was an important local dominant on mixed prairie in the foothills that functioned as an ectone between Central Great Plains grassland and Rocky Mountain forests, shrublands, and meadows. Based on the grass manual for Wyoming (and published by that state's land grant university) this plant was Festuca ovina var rydbergii. It was not clear (at least to this author) to which taxon this fescue fit in Barkworth et al. (2007, ps. 428-432), but most likely F. saximontana or F. brachyphylla.

Laramie County, Wyoming. Late June; hard-dough to grain-ripe stages of phenology.

Something to ponder (or, maybe, an imponderable): In addition to the infinite scientific phenomena there is the phenomenon of science itself, especially the scientific method. Disussions above (and elsewhere in this publication) made it clear that the matter of nomenclature and systematic arrangement of taxa is a matter that remains far from settled. This author suspects that such will never be settled--and certainly not ever to the satisfaction of all concerned. Sciencies is, afterall, a human affair and therefore subject to features of human nature including an array from admiration through envy, jealousy, and contempt as well as independent thought and defense of such thought. The nature of science is that mere mortals cannot know absolute truth, though in theory that ultimate goal becomes asyomptic. The author of Range Types suspects that in addition to, if not trumping, these aspects there is the matter of earning a livelihood (at least enough of one) so as to be permitted to continue a career in science.

As long as a sizeable part of that livelihood is contingent upon publication, especially numbers of peer-reviewed publications, it is seemingly impossible that the matter of scientific names for various taxa will ever be scientifically decided. At least not to the degree that matters of science are ultimately solved and a point of inquiry closed as is the case in "pure sciences" like Physics or Mathematics. Based on a reading of the history of Agrostology (all fields of Systematic Botany for that matter), numerous examples of which were noted herein, it seemed certain to the current author that the matter of scientific names of taxa will never be resolved. There is simply too much money (relatively speaking; by academic standards of living) to be made garnering another publication by simply pointing out that such and such a binominal was in error and "my latest research" (ie. my for-promotion-publication) showed that the more-nearly correct (better in some way) scientific name was thus and such (ie. Poa canbyi is really just an ecotype of P. secunda subsp. secunda).

Even certain areas of the Life Sciences can resolve a question in the science of Life. Biochemists elucidate and settle permanently the details of metabolic pathways. Eventually, after adequate experimentation and related forms of scientific inquiry the last enzyme or the final cofactor is fitted into the pathway puzzle and we move on to other uncharted biochemical seas. Not so taxonomists. They hash and rehash and then go back to the original hash never to settle the matter. Anatomy eventually becomes a "dead field for further research". There are professors of anatomy (at least professors who teach Anatomy), but they conduct research in related though different fields. Not taxonomists. They contemplate the femur, rationalize why the name of femure was in in error, should not have been named femur, and finally conclude (show scientifically as it were) that femur it is just the skeletal equivalent of an ecotype of the pelvis. Presto, another publication (for tenure, promotion, or at least a little bump up in salary).

As long as no more species are being discovered and written up (the typical situation, especially for vascular plants, in well-studied, thoroughly explored country) the only to get more publications is to rename and/or phylogenetically rearrange the know species. The alternative is to "close the herd book" on research in Plant Taxonomy, and provide much less employment for taxonomists (as is now the the situation for anatomists). Instead, agrostologists discover and map clades, which ties Plant Systematics to Molecular Biology (so it is bound to be more scientific, right?), and requirements for survival (Publish or Perish) are met.

That explains the winners in the taxonomy racket as it is currently practiced by some of its steller practitioners. The losers are just about everybody else. Ecologists, range and forest scientists, agronomists, even botanists besides taxonomists have to become fluent in both the old and new languages for which one traslation is incongruent with the preceding translations. What actually did this ecologist mean when he used the binominal Festuca ovina?. Some nomenclatural changes are essential and actually reduce confusion, but others gain little if anything except to create more confusion. The first (and maybe the last) description of some unit of vegetation was made when this taller, bigger-clumped bluegrass was Poa canbyi and this littlier bluegrass was Poa sandbergii. Now decades later, how can another vegetation scientist know whether P. secunda subsp. secunda was the P. canbyi or P. sandbergii or just plain P. secunda used by the earlier describing scientist?

Finally, ponder this. How can so many outstanding (supposedly) agrostologists look at the same plant (same taxonomic entity), even the same type specimen, and interpret it in so many different ways. How can one agrostologist or group of agrostologists conclude that the same plant (or specimen) is a different species, in a different species, or even in another genus than the one chosen by preceding agrostologists? They even construct dichotomous keys based on readily observed and key morphological features that lump and split and relump in as many different arrangements as there are taxonomists doing the arranging. Hitchcock and Chase (1951) saw this plant as this, Gould (1975) saw it as that, and Barkworth et al. (2007) saw it a third way. Is Taxonomy mostly in the eye of the beholder? If so, is this really science? How can instructors present Plant Systematics as solid science to undergraduates when there are four names for Canby's bluegrass in four different manuals all written by agrostologists? Do agrostologists ever ponder this? Do they care?

131. Tufted fleabane (Erigeron caespitosus)- This specimen of a widely distributed DWC (Damn White Composite) was growing on the Canby bluegrass-Wyoming threetip sagebrush-dominated, foothill mixed prairie range presented above. The head of this species is typically disproportionately large for the rest of the shoot which makes it a conspicuously showy forb though one of relatively restricted species range.

Erion is Greek for wool which was obviouly in reference to pubescence of s

Albany County, Wyoming. Late June; peak bloom stage of phenology.

132. Whiskbroom parsley (Harbouria trachypleura)- This member of the Umbelliferae was one of the more common forbs in the foothills of the Front Range. It was frequent on Canby's bluegrass-dominated mixed prairie and true mountain mahogany (Cercocarpus montanus) shrubland like those in the Laramie Range extension of the Front Range as well as at lower elevtion in the western part of Great Plains grasslands. This is not a particularly large member of the carrot or parsley family, but it is a native forb (unlike many other species of the Umbelligerae that naturalized in North America). This specimen was growing on a droughty environment at edge of a stand of true mountain mahogany in the Sherman Mountains of the Laramie Range.

Laramie County, Wyoming. Late June; full-bloom stage.

133. Umbel of whiskbroom parsley- An example of the rather sparse inflorescence on the specimen introduced immediately above. This is a native umbelliferous forb found in the Front Range and adjoining parts of western Great Plains.

Laramie County, Wyoming. Late June; full-bloom stage.

134. More light on a bluegrass prairie (as if it was needed)- Miner's candle (Cryptantha virgata= Oreocarya virgata) growing on a bluegrass-dominated mixed prairie in the Laramie Mountains. This species is a member of the Boraginaceae (borage family). It was one of a very few forbs on this mixed prairie range in the Sherman Mountains of the Laramie Range.

Albany County, Wyoming. Late June; full-bloom phenological stage.

135. Mixed prairie with maximum diversity- Classic mixed prairie in Southern High Plains on a level local plain with soil ranging from sandy to deep sand. This range vegetation was a textbook example of mixed prairie having major components from all three grass height groups including: tallgrass species of sand bluestem, little bluestem, and Indiangrass; midgrass species of sideoats grama, silver bluestem, plains lovergrass, red threeawn, and sand dropseed; and shortgrass species that were limited to buffalograss and blue grama. There were widely scattered plants of cheatgrass or downy brome. This naturalized Eurasian annual was the only cool-season grass this photographer found. (Soil was too sandy, well-drained, to support western wheatgrass.) Forbs were almost nonexistent except for some of the standard tumbleweed, Russian thistle, and a few widely scattered plants of wild alfalfa or slimleaf scurfpea and broom snakeweed. Shrub species included sand sagebrush, soapweed yucca, and plains pricklypear. This was an isolated example of bluestem-grama prairie that is far more typical to the east in areas of greater precipitation. The deep sand of this rangeland permitted development of a climax range plant community that occurs only locally in this region where isolated communities generally come into contact with the more widespread and xeric blue grama-buffalo shortgrass country (description of SRM 604 in Shiflet, 1994, p. 73). In this area of High Plains and on sandy soils sand bluestem replaces big bluestem, this latter of which is the ecologically equivalent species in the typically higher precipitation belts in the greater zone of this rangeland cover type (description for SRM 709 in Shiflet, 1994, ps. 89-90).

Range condition was obviously--even, glaringly--in the Excellent class.All plants were in drought-induced dormancy in this eighth straight year of drought which was classified in the category of Extraordinary Drought. This particlar range had been destocked, apparently due to high cattle losses from a blizzard the previous winter. There was abundant dead (and only slightly weathered) herbage for cattle feed on this range. This can be compared to a range that was almost exclusively buffaograss which was being grazed just about five or six miles right down the road from this destocked pasture. Some of the standing brass biomass on this range was perhaps two or more years old. Only time would tell how many of the plants seen here had survived or could live through another growing season of drought. The species composition as estimated from a general mental calculation of biomass, cover, density, and relative abundance of herbage certainly was tht of climax mised prairie in, as stated above, in Excellent condition class.

A beautiful mixed prairie range even in Extraordinary Drought. Although this range vegetation would have been prettier if green in a wet year its appearance at its worst displayed the species make-up, botanical diversity, and herbage yield of which High Plains grassland is capable when proprly managed. For impressionable students that phenomenon was even more extraordinary than the devestation wrought by the worst of drought conditions.

Baca County, Colorado. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 604 (Bluestem-Grama Prairie) and/or SRM 709 (Bluestem-Grama). Brown et al. (1998, p. 40) did not provide a series for this climax vegetation under Plains Grassland biotic community, 142.1. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al.l, 2006).

136. Two more examples of maximum diversity mixed prairie- Two other pastures of mixed prairie on the Southern High Plains in which tallgrass, midgrass, and shortgrass species were all major components. Both pastures had plants of the following grass species: sand bluestem,. little bluestem, silver bluestem, sideoats grama, red threeawn, sand dropseed, plains lovergrassblue grama, and buffalograss. Wild alfalfa or slimleaf scurfpea was the main forb. Broom snakeweed was an infrequent subshrub. Shrub species included plains prickly, walkingstick cholla and soapweed yucca. On these two ranges prairie sagewort or fringed sagebrush (Artemisia frigida) replaced sand sagebrush as a representative of that genus.

Both of these pastures were approximately 20-25 miles west of the range presented in the immediately preceding photographs. All ranges were photographed during the same morning. This area had been in eight years of prlonged drought culminating in a rating of Extraordinary Drought.The obviously greater quantity of green plant tissue on the second of these two ranges was due to a fortituous shower a few weeks prior to photograph. This was much greater sod coverage (sod-forming grasses like buffalograss) on this "tight land" (higher clay content) as opposed to greater patchiness of bare ground on the deep sand to sandy soil of the previous range.

Las Animas County, Colorado. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 604 (Bluestem-Grama Prairie). Brown et al. (1998, p. 40) did not provide a series for this climax vegetation under Plains Grassland biotic community, 142.1. Southwestern Tablelands- Piedmont Plains & Tablelands Ecoregion, 26e (Chapman et al.l, 2006).

137. More typical--though still diverse--mixed prairie- Another range of mixed prairie in the Southern High Plains, but of another rangeland cover type from those shown previously in this drought-stressing section. Range vegetation in this example included some local depressions with enough finner (lighter)-textured soils to support western wheatgrass. This added a major coll-season native perennial grass to the overall plant community of this mixed prairie range. However, the tallgrass component (sand and little bluestems) was absent from this range vegetation. There was also considerably more ground cover by the sod-forming buffalograss. Other important grasses included silver bluestem, sideoats grama, blue grama, and sand dropseed. In contrast to the other examples (and other range types) presented in this "dual purpose" section this climax range plant community was defined by both warm- and cool-season dominants (ie. grama grasses along with buffalograss and western wheatgrass, respectively). There was also some cheatgrass or downy brome, but this was limited on this range that was in Good range condition class. It was also likely that the absence of adequate soil moisture due to conditions of Extraordinary Drought in full force prevented germination of grains.

Wild alfalfa or slimleaf scurpea was also more common (more cover and more widespread in occurrence). Shrubs included plains pricklypear, walkingstick cholla, and soapweed yucca. Prairie sagewort or fringed sagebrush was locally common while plants of broom snakeweed were more sparse, but being larger and bushier plants each one of these individuals comprised more cover than a plant of Artemisia frigida. These two species have usually been described as subshrubs that could be regarded as either shrubs or forbs.

Las Animas, County, Colorado. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-61 (Wheatgrass-Grama-Buffalograss). SRM 704 (Blue Grama-Western Wheatgrass). Mixed "Short-Grass" Series, 142.13 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Southwestern Tablelands- Piedmont Plains & Tablelands Ecoregion, 26e (Chapman et al., 2006).

138. Drought-stricken but still Excellent- In its eighth straight year of drought this mixed prairie range still showed the physiogonomy, species composition, foliar cover, plant density and so forth of climax or potential natural vegetatio. At time of these photographs this area was experiencing Exceptional Drought (Category D4; Palmer Drought Index of -5.0), the highest (worst) rating on the Drought Severity Classification. These two photographs and the following two were different views of the same pasture. These four "photo=quadrants" showed the diversity in range plant species and plant growth forms that frequently varied at local scale. Patchiness of blue grama and buffalograss, the two main shortgrasses, along with a few small plants of rubber rabbitbrush (Chrysothamnus nauseosus) was shown in the second of the two slides presented here. Predominant range plant species in the first of these photographs and in areas of taller herbage in the second photographs included western wheatgrass, silver bluestem, sideoats grama, galleta, red threeawn, and sand dropseed. Indian ricegrass was also present, but not as a major species. Cheatgrass or downy brome was almost nonexistent. This may have been partly due to inadequate soil moisture.

Broom shakeweed occurred as scattered individuals (ie. there were not groups or locally dominated spots of this species). Plains pricklypear, an ever-present species on ranges in this area, was also well-represented though at cover and density of climax vegetation (= Excellent range condition class, as this range plant community certainly was). Walkingstick cholla was also represented. Yucca glauca is also found on almost every range in this area, including the range featured here. Wild alfalfa or slimleaf scurfpea was the major forb. It was not common on the more lowland land form.

Las Animas, County, Colorado. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-61 (Wheatgrass-Grama-Buffalograss). SRM 704 (Blue Grama-Western Wheatgrass). Mixed "Short-Grass" Series, 142.13 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Southwestern Tablelands- Piedmont Plains & Tablelands Ecoregion, 26e (Chapman et al., 2006).

139. How to stock for drought- Two other "photo-plots" of the Excellent condition class western wheatgrass-gramagrass-buffalograss mixed prairie range introduced immediately above. Blue and sideoats grama, galleta, sand dropseed, red threeawn, and silver bluestem were also important species. Indian ricegrass was present, but more as an indicator plant (decreaser species). Forbs were very infrequent and were limited mostly to wild alfalfa or slimleaf scurfpea. Shrubs were uncommon, but woody and semi-woody species included broom snakeweed, rubber rabbitbrush, soapweed or pale yucca, plains pricklypear, and a few walkingstick cholla.

Students' attention was directed to the amount or quantity of standing crop or herbage remaining on this range that was currently being grazed by cows and calves. One of the main reasons why these photographs were included--in spite of ugly, dead foliage in early summer--was to present outstanding stewardship of the rangeland and superb husbandry of the beef cattle grazing it. The rancher managing this range knew how important it was to stock conservatively and have as light a degree of use as possible under a long-lasting drought with "no end in sight". Extraordinary Drought calls for extraordinary management of all resources including those of rangelands and other pastures. The owner ( manager) of this range and these cattle exemplified wise (proper) use of that under his charge.

Las Animas, County, Colorado. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-61 (Wheatgrass-Grama-Buffalograss). SRM 704 (Blue Grama-Western Wheatgrass). Mixed "Short-Grass" Series, 142.13 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Southwestern Tablelands- Piedmont Plains & Tablelands Ecoregion, 26e (Chapman et al., 2006).

140. Drought-smitten shortgrass plains- Southern High Plains grassland on which potential natural (climax) vegetation is domination by blue grama and buffalograss with substantial cover of sideoats grama, sand dropseed, and even some silver bluestem. This deteriorated range had been degraded to a nearly "solid" or "pure" stand of buffalograss, a grazing disturbance climax. Some cover of blue grama occurred in isolated patches. There were enough, even more widely isolated individual plants of sideoats grama (all of them had received heavy to extreme degree of use) to indicate that this midgrass was an associate species and, therefore, that the potential natural vegetation of this range was a mixed prairie with a clear predominance of shortgrass species.

This author had periodically observed this particular cattle range over a period of 40 years. It was consistently managed under (with) heavy grazing during that span of time. It remained a buffalograss disclimax with almost no change of any sort in species composition, physiogonomy, etc. Even under this heavy defoliation buffalograss had maintained the cover and density of shoots shown here. A few plants of wild alfalfa or slimleaf scurfpea comprised the forb component of this disturbance climax. There were some Yucca glauca plants (at the general size, cover, and density shown in the second photograph) so that this was the major shrub species. Plains pricklypear was the second most common shrub. There were also a few plants of the subshrub, broom snakeweed.

This range was destocked (and had been for some time) when these photographs were taken. A cattle range adjacent to (conterminous with) the range shown here was current stocked with beef cattle that were being maintained with survival feeding (shown and explained below). Question: what, if any, affect would presence of cattle on this range under these feed and plant-growing conditions (survival feeding, drought-induced dormancy) have on this range vegetation?

At time of these photographs the impacts of eight straight years of drought, culminating in Exceptional Drought (the condition shown in slides) was being manifest. Exceptional is the highest or worst category of Drought Severity Classification (Palmer Drought Index of -5.0) used by the US Drought Monitor program. These photographs bespoke of the grazing resistance and drought tolerance of buffalograss.

Cimarron County, Oklahoma. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss) and/or SRM 611 (Blue Grama-Buffalo Grass): both of these rangeland cover types (Shiflet, 1994, ps. 93-94, 79-80, respectively) included the High Plains region of Oklahoma, Texas, and New Mexico in their descriptions. Grama "Short-Grass" Series, 142.12 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Deep Hardland range site. High Plains- Moderate Relief Plains Ecoregion, 25c (Woods et al., 2005).

141. Two range sites in High Plains drought- Two range sites in the Southern High Plains: Deep Hardland (foreground) and a Breaks (background) range site in the background under conditions of Exceptional Drought. This range and its vegetation was in the same cattle pasture described in the immediately slides and caption. The Deep Hardland site is a simple shortgrss (plains) prairie, the climax vegetation of which is blue grma-buffalograss as con-dominants with sideoats grama as associate species. Plants of sideoats grama had been grazed to down to the height as that of buffalograss. This range plant community had been been depleted to a single species stand (a population) of buffalograss. Such range vegetation would probably be most accurately described as a anthropogenic (man-induced) disclimax, a zootic disclimax in which cattle-grazing caused almost complete replacement of blue grama, the potential dominant, and sideoats grama, the natural associate, by buffalograss, the lesser co-dominant in the climax range vegetation.

The Breaks range site was dominated by skunkbush sumac (Rhus trilobata= R. aromatica) odorata). Otherwise, plant species present were the same as on the Deep Hardland site though with noticeable more sideoats grama. Cattle had grazed the range vegetation of this low Breaks site. Currently no cattle were on this range under the conditions of Exceptional Drought that were explained in the preceding caption.

Cimarron County, Oklahoma. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss) and/or SRM 611 (Blue Grama-Buffalo Grass): both of these rangeland cover types (Shiflet, 1994, ps. 93-94, 79-80, respectively) included the High Plains region of Oklahoma, Texas, and New Mexico in their descriptions. Grama "Short-Grass" Series, 142.12 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). High Plains- Moderate Relief Plains Ecoregion, 25c (Woods et al., 2005).

142. About as bad as it gets- Degraded shortgrass plains range that is essentially a single-species stand of buffalograss in a drought ranked as Exceptional, the worst or highest rating on the Drought Severity Classification scale (Palmer Drought Index of -5.0). Beef cattle were being fed emergency. This cattle range was adjacent to the destocked cattle range described in the preceding two photo-captions.

This herd was being kept alive by maintenance feeding, the practice of providing a balanced ration (complete diet) to livestock for prolonged periods as in extended drought. Cattle were essentially getting "next to nothing" from the remaining range herbage (it was too short for them to be able to eat much of it). Under this situation what, if any, impact would continued cattle stocking have on this range? Cattle were in effect being kept on this rangeland rather than paying out additional expense of moving (as by shipping or trailing) them to a dry lot. Or said another way, cattle were being dry lotted on the range where they were fed a maintenance diet rather than either paying to rent a lot or paying to have them fed (or, alternatively, to sell the herd). Given that range plants were in drought-dormancy and there was no feed left for cattle on the range (they could not remove anymore plant material by eating) did range-retention of cattle induce damage--and if so, how much--to the land and/or plant life? Other than damage by trampling or dunging, which could have been slight to considerable, the answer is that continuing to keep non-grazing cattle on the range most likely had limited adverse impact. Once buffalograss, about the only plant species present, started to green up "if and when it rained again", continuing to stock cattle could have a detrimental influence if grazing exceeded feeding (immediate grazing) capacity of the range (ie. stocking during plant recovery resulted in overuse of regrowing buffalograss).

Management of ranch resources (range, livestock, financial, internal structures, labor, equipment, etc.) under adverse situations is an art form based on rational financial, scientific, cultural, etc. factors. This is risk management in ranching. Drought is the great risk in in sermiarid regions such as the Great Plains.

Cimarron County, Oklahoma. Late June; early summer with plants in drought-dormancy. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss) and/or SRM 611 (Blue Grama-Buffalo Grass): both of these rangeland cover types (Shiflet, 1994, ps. 93-94, 79-80, respectively) included the High Plains region of Oklahoma, Texas, and New Mexico in their descriptions. Grama "Short-Grass" Series, 142.12 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). High Plains- Moderate Relief Plains Ecoregion, 25c (Woods et al., 2005).

143. Shortgrass plains- This was an example of the shortgrass phase or shortgrass community form of mixed prairie. Blue grama and buffalograss were the two dominants of this climax grassland, but western wheatgrass, sideoats grama, and sand dropseed (the classic mid-grasses) were also common while silver bluestem formed distinct colonies (eg. the light tan area in left mid-ground) and individual plants of the cespitose little bluestem were also present. Dominant forb was wild alfalfa. This combination of sod-forming grasses and bunchgrasses is characteristic of mixed prairie, but the predominant sod-grasses were responsible for the shortgrass physiogonomy of this Southern High Plains grassland. The community more typical of mixed prairie (more species-rich) was featured in the foreground to show the biological diversity of plains grassland, but the less diverse blue grama-buffalograss community of the background was the more common community on this cattle range.

Commanche National Grassland, Baca County, Colorado. Estival aspect, July. FRES No. 38 (Plains Grassland Ecosystem). K- 61 (Wheatgrass-Grama-Buffalograss) in foreground; K-58 (Grama-Buffalograss) in background. SRM 715 (Grama-Buffalograss). Grama "Short-Grass" Series of Brown et al. (1998). Hardland range site. Hardland range site. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2005).

144. High Plains grassland- This was another example of the shortgrass physiogonomy form of mixed prairie. Blue grama, buffalograss, and galleta (in that order) were dominant species though mid-grass species were common (western wheatgrss, sideoats grama, sand dropseed, and Indian ricegrass were well-represented while prairie junegrass was present but infrequent in this sward). Common plains yucca or soapweed yucca was present as the major forb, but it was more conspicuous than it was common. Widely scattered (barely present) shrubs were cholla and four-wing saltbush.

Crowley County, Colorado. July. Estival aspect, July. FRES No. 38 (Plains Grassland Ecosystem). K- 58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss). Grama "Short-Grass" Series of Brown et al. (1998). Loamy Plains range site. Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

145. Shortgrass plains- This landscape was included to show viewers the classic blue grama-buffalograss community interpreted by many prairiemen as a shortgrass disclimax (a grazing or zootic disturbance climax). Beginning range students are referred to Weaver and Albertson (1954, ps. 19-25). The two shortgrass species "have a monopoly" on the plant-growing resources of this ecosystem. As with the grassland communities seen in preceding slides such species as western wheatgrass, sideoats grama, and galleta were also present. Threeawns (Aristida species) were very rare while shrubs and even forbs were non-existant for all practical purposes. Textbook example of shortgrass plains grassland.

From the collection of examples presented here the most ardent plainsmen and fans of the "shortgrass country" can understand why plains-weary travelers (and some "foreigners" not so travel-weary) find this landscape so monotonous and boring. To the true plainsman, however, it is "God's Country" and the finest place on Earth.

Elbert County, Colorado. Estival aspect, July. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 715 (Grama-Buffalograss). Grama "Short-Grass" Series of Brown et al. (1998). Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).

146. Mature sand dropseed (Sporobolus cryptandrus)- Appearance of adult sand dropseed plants complete with the cryptic infloresences still enclosed within the boot. West Texas Cross Timbers. Erath County; Texas. Late August.

147. Sand dropseed (Sporobolus cryptandrus)- This mid-grass is one of the most widely distributed grasses in North America. The biological range of this species is literally from Atlantic to Pacific and from northeastern North America into the deserts of the Southwest. It is generally an increaser that is most common on grasslands in various mid-sere communities, but sand dropseed is a climax or at least higher seral stage species on certain range sites of mixed prairie, Palouse Prairie, and semidesert grasslands (Dodd, in Gould, 1968, ps. 331, 334, 336). As suggested by the common name of sand dropseed the most favorable edaphic habitat for this widespread grass is that containing higher proportions of sand (or, sometimes, gravel).

Sand dropseed is not as palatable as some of the grasses with which it is associated but it does furnish moderate to high quantities of forage that is of good down to fair nutritive value with increasing stages of maturity. (The individual shown here was past seed-shatter stage and approaching the dormant stage when forage value is lowest.). Although sand dropseed is a bunchgrass it does have fair to good sand-binding potential due to it's preference for coarse-textured soils.This common range grass was one of the 200 range plants on the Master List of the International Range Plant Identification Contest sponsored by the Society for Range Management.

Taylor County, Texas. October.

148. Sand dropseed at peak bloom- This plant had been mowed frequently during the summer growing season on Texas' Rolling Red Plains such that it was stunted and blooming at end of autumn (less than a month before first frost). The entire aboveground portions of this cespitose species were obvious in this depauperate individual. (Runt specimens formed by stresses such as over-utilization frequently make some of the best examples for overall or composite shots of a plant because their short stature provides greater depth-of-field.)

Soil chroma shown here was representative of soils on the Rolling Red Plains, Rolling Redlands, or simply Redhills section of the Great Plains physiographic province that extends fromn Texas to southcentral and southwest Kansas. The smaller (and mowed) bunchgrass in the right background was Texas wintergrass which is commonly co-dominant with sand dropseed on deteriorated mixed prairie ranges throughout this general area.

Taylor County, Texas. October.

149. Panicles of sand dropseed- These inflorescences of S. cryptandrus exhibited the two basic forms or patterns of this species: 1) fully exerted pyramidal-shaped and 2) partially or entirely included (= enclosed) within the sheath (ie. still largely inside the boot). The latter is basis of the specific epithet, cryptandrus, meaning crypt-like or hidden as in a crypt.

Taylor County, Texas. October (flowering delayed by repeated defoliation).

150. Stand of maturing sand dropseed- Local population of sand dropseed nearing senescence and dormancy in mid-autumn in the West Cross Timbers of northcentral Texas. Besides nearing end of their annual growing cycle these perennial plants were suffering from the stress of moderate to severe drought. Furthermore, plants of sand dropseed that are growing in sand typically reach larger size (height, number of tillers, area covered) and exhibit more vigor than those growing on 'tighter" soil.

Erath County, Texas. October; grain-shatter stage.

151. Just to make sure there's enough- Three examples of panicles in sand dropseed. Sand dropseed is one of the most widely distributed grasses in the mixed prairie and adjoining range types. It is often stated among Texas rangemen that there are probably more plants of sand dropseed than of any other grass species in the state. Given such commonness and widespread distribution, plenty of examples of sand dropseed were included herein. Incidentally, sand dropseed is one of the more difficult species of grass to present photographically to good advantage (and of course few, if any of the Gramineae are photogenic to the degree of the more colorful forbs).

Identifying details of the sand dropseed inflorescence were presented in the next set of slides and their caption.

Erath County, Texas. October; grain-shatter stage.

152. Hidden up close- Two views of the incompletely expressed or extended panicle of sand dropseed. In this species the mature panicle typically remains partially to almost completed enveloped within the sheath rather than becoming emergent (ie. the inflorescence stays in the boot even upon maturity) This results in panicle branches remaining pressed (appresed) against against the central axis of the inflorescence and the sheath having a "swollen" appearance. The specific epithet cryptandrus means "with hidden flowers". Thus the scientific name of this species is based on the morphological feature of an incompletely exposed or extended inflorescence.

Diggs et al. (1999, p. 1327) cited work that reported the tiny grains of this species being eaten by American Indians. As if dietary use of Indian ricegrass (Oryzopsis hymenoides) was not "hard scrample" enough.

Erath County, Texas. October; grain-shatter stage.

153. A key characateristic- Rings of straight, relatively long, white pubescence surrounding the collar on a shoot of sand dropseed. This morphological trait and retention of portions of the lower panicle within the sheath (boot) have long been regarded as the key identifying features of sand dropseed, especially in the field. Hatch and Pluhar (1993, p.109) stated that "the most distinguishing feature of this grass are [sic] the long dense hairs at the collar".

Erath County, Texas. October; grain-shatter stage.

155.  Sideoats grama (Bouteloua curtipendula)- The State Grass of Texas is the textbook example of a midgrass species. It is the dominant grass over much of the Mixed Prairie and is often co-dominant at larger spatial scales (regions) with other midgrasses like western wheatgrass. Central and western portions of the Mixed Prairie support a higher cover of midgrass than of tallgrass species and some of the more mesic sites of the western zone of Mixed Prairie have a greater proportion of midgrass than of shortgrass species. As such, Mixed Prairie is sometimes known also as Midgrass Prairie even though some species of the three general grass groups are common. Sideoats grama includes both rhizomatous (B. curtipendula var. curtipendula) and non-rhizomatous or bunchgrass (B. curtipendula var. caespitosa) forms. These two varieties are sometimes co-existent as on ranges in the Cross Timbers, Edwards Plateau, Rio Grande Plains, and Trans Pecos Basin and Range Regions of Texas. While the specimen seen here appears to have the bunchgrass or cespitose growth form it is actually the rhizomatous variety which is growing in isolated strips or patches of soil between slabs of limestone which is the parent material of the Grand Prairie supporting this lovely grass.

Like other Bouteloua species and such short grasses as buffalograss, and curly mesquite sideoats grama “cures on the vine”(ie. the dormant, dried leaves and even stems retain a fairly high proportion of the nutritive value of the growing plant). This phenomenon, which is due to a combination of several factors such as the nature of eragrostoid vs. panicoid grasses and dry winters in which nutrients are less leached from herbage, was described as “self-curing” and was seen as the basis of “winter grazing” on the Great Plains. This was recorded in the prescient report by Dr. Hiram Latham (1871): Trans-Missouri Stock Raising. The Pasture Lands of North America: Winter Grazing. This is one of the rarest of all materials dealing with the Western Range. It was re-published by The Old West Publishing Company in Denver, Colorado with an introduction by J.C. Dykes (1962). Well worth the effort to borrow or buy and read this seminal view of early North American ranching. It is just another example of the rich recorded history of Range Management.

This is an example of a range microsite. It is a Brackett soil that is too small for a mapping unit in the soil survey. The Brackett is situated between the general Purves Dugout soil association. This narrow strip of Brackett is a “postage stamp-size” of the Limestone Hills range site within the larger, surrounding Rolling Prairie range site. The limestone outcroppings spread water to the intervening Brackett soil to create a mesic microhabitat. On both of these range sites sideoats grama is an increaser while the predominant decreasers are Indiangrass and little bluestem.

Even in a “rockpile” on plate-thin soil and four years into the worst drought in a half-century this prairie beauty is blooming profusely to assure the perpetuation of its genetic heritage. Erath County, Texas. October.

157. Texas grama (Bouteloua rigidiseta)- Hitchcock and Chase (1951) divided Bouteloua into two sections: 1) those with spikelets arranged in a pectinate (like the teeth of a comb) pattern and 2) those with spikelets not arranged in a pectinate pattern. Texas and sideoats grama are in 2) or not pectinate. Unfortunately this taxonomic relatedness did not result in Texas grama sharing the forage value or ecological status of it’s section mate. Texas grama is not only a species of low forage value (due primarily to low productivity), but it is also invariably an ecological invader and indicative of disturbances like overgrazing. The generally low palatability and small size of this grass coupled with high rates of reproduction allow this invader to survive abuse and persist on depleted ranges. 

Texas grama is an indictor plant, a species either: 1) indicating presence of certain environmental conditions, seral stages, or previous management and/or 2) chosen to indicate a certain degree of grazing use (Kothmann, 1974). In theory, all species are indicators of some environmental factor or condition. The concept of plants as ecological indicators was the basis of the second epic ecological monograph,  Plant Indicators, by F.E Clements (1920) which was the sister volume and the more practical companion to his earlier and more famous Plant Succession (Clements, 1916). It was from the concepts explained in Plant Indicators that students in the plant ecology school of thought centered at the University of Nebraska developed many key applications such as use of quantitative ecology to determine range condition and trend based on climax or potential natural vegetation and the categories of decreaser, increaser, and invader.

159.   Racemes of hairy grama- This is an example of the pectinate form of racemes in Bouteloua species. Erath County, Texas. October.

162. Blue grama- Bouteloua gracilis is viewed by many range scientists as the single most important range plant in North America from the standpoint of its wide geographic distribution, dominance of total land area, impact on range ecosystems within its range, and forage contribution to range animal diets. Quite likely the only other range plant to offer any opposition to this distinction would be little bluestem, depending on whether certain taxa are interpreted as separate species or varieties of little bluestem. Of course any of the tallgrass species have the deck stacked against them now that so much of the land in their former species ranges was claimed by the plow. That matter clarified, students should remember that this is a widely distributed species (from the Atlanic states and provinces to the southwestern deserts and the western side of the Rocky Mountains). Blue grama occurs on some sites of every major grassland except the Pacific bunchgrass prairie. While the Great Plains is the center of it's range blue grama is locally common even in the shade of tallgrass species as in this example where it grew on a big bluestem- dominated prairie in the Dissected Till Plains of the Central Lowlands. The Central Lowlands is the general physiographic province of the Prairie Plains region and it's grassland vegetation.

Homestead National Monument, Gage County, Nebraska. August.

163. "King Grass of the Mixed Prairie"- Blue grama is the unquestionable overall dominant and the single most important range plant species of the mixed (and perhaps of the shortgrass) prairie. This is so in particular for the unit of potential natural vegetation designated as "Grama-Buffalo Grass" (K-65 in Kuchler, 1964; K-58 in Kuchler, 1966) extending from the Southern High Plains of Texas, Oklahoma, New Mexico, Kansas, and Colorado through to the Central High Plains of northeastern Colordo and southeastern Wyoming. This is probably the single largest unit of climax grassland vegetation in the Great Plains province. It would be rivaled only by the "Grama-Needlegrass-Wheatgrass" unit to its north (K-64 in Kuchler, 1964; K-57 in Kuchler, 1966). another climax grassland community in which blue grama is a dominant.

It would be difficult indeed to exaggerate the extent, economic and ecological importance, and role of blue grama in North American grasslands, and the drama of human occupation of this vast region. The noble Indian tribes of the Great Plains with their existence intricately tied to the buffalo depended on blue grama, a mainstay of the buffalo ranges, for their 10,000 to 12,000 years of occupation.

Blue grama frequently (perhaps even typically) grows in association with other range plant species, but it also forms natural and extensive single-species stands. These almost exclusive populations of blue grama or range plant communities in which blue grama is the sole dominant constitute what Clements termed a consociation. In the classic Grassland of the Great Plains Weaver and Albertson (1956, 149-150, 253-254) described co-dominance and close affilitation of blue grama and buffalograss. When blue grama is co-dominant with buffalograss it is--contrary to popular opinion and perception--blue grama that is the more drought-tolerant species (Weaver and Albertson, 1956, ps 33, 104). Clearly, "... buffalo grass is less drought resistant than blue grama" and, also, "[B]lue grama is much more drought resistant than buffalo grass... (Weaver and Albertson, 1956, p.79, 133, respective quotes). The stoloniferous buffalograss did spread faster and more effectively than the cespitose blue grama in revcovering from the Great Drought of the 1930s from which the preceding experimental findings were derived.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and anthesis stages of phenology.

164. Blue grama in early morning sun- An individual plant of blue grama at anthesis with early morning sunlight catching features of this bunchgrass just right. All blue grama shoots are tillers (upright, intravaginated) so this species is strictly cespitose. At end of an extremely wet growing season that extended from the preceding winter through until early autumn the blue grama plants featured in this section had a high proportion of their shoots progress to the sexual reproduction stage. This individual plant was at peak bloom-- and beauty.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and anthesis stages of phenology.

165. A study in shoots- A single blue grama plant most of the shoots of which developed to the stage of sexual reproduction. A wet growing season preceded by a wet pre-growth (dormant) season were the major plant growing conditions responsible for such a high proportion of sexually reproductive shoots rather than the typical condition in which substantially fewer tillers progress to stages of inflorescence development and anthesis. Even under drier conditions, however, short-shoot grasses like blue grama have a higher percentage of their shoots that advance to flowering.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and anthesis stages of phenology.

166. Racemes of blue grama- The inflorescence type in Bouteloua has traditionally been regarded as a raceme, but in more recent times it was often described as an inflorescence consistinf of "short, spicate branches" (Gould and Shaw, 1983, p. 298). The racemes of the Chondrosium section of Bouteloua the racemes (spicate branches of the inflorescence) have numerous pectinate (an adjective referring to packed, downward-oriented floral units like teeth on a comb) spikelets (Gould and Shaw, 1983, ps. 299, 380).

The anthers in these racemes were fully exerted and conspicuous.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; anthesis.

168. Racemes of blue grama- Even after a wet winter and almost midway into a Texas spring a few spikelets persisted on this blue grama raceme. Young County, Texas. April.

169. Galleta (Hilaria jamesii)- Galleta is one of two major Hilaria species on the Great Plains (H. belangeri being the other). This eragrostoid grass is either decreaser or increaser depending on range site. It is one of the more productive grasses on the "tight land" (high clay) ranges of the High Plains. It is also fairly palatable and overall one of the more desirable grasses on certain range sites and range types. For comparative purposes it is considerably more productive than buffalograss though it does not "cure" as well (retain nutrients in states of dormancy or semi-dormancy). For this reason galleta--as is typical of most Hilaria species--is quite unpalatable during late autumn through winter and into early spring.

The specimen(s) shown here was probably one (or two) clones of a large plant on an overgrazed and severely degraded range in the Rolling Red Plains of the southern Texas Panhandle. This provided a good example of the habit of this highly rhizomatous member of the Chlorideae tribe.

Scurry County, Texas. October. Phenology: entering dormancy, immediately following grain-shatter.

172. Curly mesquite (Hilaria belangeri)- Sward of curly mesquite. This is one of seven Hilaria species in North America, four of which are important range grasses. According to Gould (1951, p. 159) H. belangeri is the most palatable of these species, all of which are sod-forming (rhizomatous and/or stoloniferous). Curly mesquite has been the Hilaria species typically regarded by rangemen as a dominant of the "shortgrass country" (both shortgrass plains and overgrazed mixed prairie) and a species associated with such other shortgrass species as buffalograss and blue grama. Other vegetation specialists, particularly vegetation classifiers and mappers, in more recent works interpreted galleta (H. jamesii) as the dominant Hilaria on the Great Plains grasslands. For example, the Kuchler (1964, 1966) unit K-58 (Gramagrass-Buffalograss) did not list curly mesquite (Kuchler, 1964, p. 65). The Society for Range Management (Shiflet, 1994) did not even mention curly mesquite in descriptions of rangeland cover types SRM 705 (Blue Grama-Galleta) and SRM 715 (Grama-Buffalograss) of the Southern Great Plains Region. Dick-Peddie (1993, p. 104) gave galleta and not curly mesquite as the associate of the codominants, blue grama and buffalograss, of plains-mesa grassland. Curly mesquite does not grow in the central and northern Great Plains, but galleta occurs as far north as Wyoming so it is the Hilaria species sometimes found in rangeland cover type SRM 611 (Blue Grama-Buffalograss) of the Northern Great Plains Region.

In the experience of the current author omission of curly mesquite was somewhat erroneous, misleading to say the least. From his observations this author felt that Thomas (in Correll and Johnston, 1979, p. 11) was much "closer to the mark" when he listed curly mesquite immediately following buffalograss as a major increaser species on the Texas Rolling Red Plains portion of the Great Plains. Perhaps this was the reason why other (and more recent) authors did not list curly mesquite: it is an increaser and not a decreaser on most range sites (ie. it is not a climax species or a major species of the potential natural vegetation).

[By the way, this was still more evidence that SRM rangeland cover types typically resemble quite closely the climax or potential natural vegetation in spite of statements that explained SRM cover type "classification is based on existing vegetation" such that of these types "...most do not..." coincide with those of Kuchler (Shiflet, 1994, p. xi-xii). In fact the SRM rangeland cover types of the Great Plains province included essentiallly all of the Kuchler units of potential natural vegetation, and most of the other Great Plains rangeland cover types that did not correspond exactly with Kuchler units were smaller spatial subunits of these. One thing was certain: if qualifying statements given in Shiflet (1994, ps. xi-xii) were taken literally there would definitely have been far more reference to curly mesquite as well as a curly mesquite rangeland cover type. There are thousands of acres in the Texas Great Plains on which the dominant herbaceous species is curly mesquite, typically with honey mesquite as a scattered overstorey. This plains vegetation is a widespread form of depleted range: a seral stage on rangeland damaged by various combinations of former cultivation or "go-back land", severe overgrazing, oil and gas activity, and perhaps unique meteorological sequences of events or even climatic changes.]

The indespensible Pasture and Range Plants (Phillips Petroleum, 1963, p. 43) explained that curly mesquite had "increased and invaded ranges where better grasses were killed out by abusive grazing". Furthermore, curly mesquite is less palatable than buffalograss and blue grama and goes dormant earlier in drought all of which enable curly mesquite to survive "when better grasses die or thin out". While curly mesquite forms a dense sward such as the one shown here it's "forage production is very low when compared to the better grasses it replaced." (Phillips Petroleum Company, 1963, p. 43).

Regardless of successional status, forage value, soil cover, or usefulness as an indicator species, curly mesquite is-- for better or worse-- a nonclimax dominant on many ranges throughout much of southern Great Plains, a vast range region. In something of an overstatement when applied to the Rolling and High Plains Hitchcock and Chase (1950, p. 485) got the essence of the situation in regards curly mesquite: "Curly mesquite is the dominant 'short grass' of the Texas plains". (When the Rio Grande Plains are included this statement was "right on target".) Silveus (1933, p. 361) wrote that curly mesquite "is one of the most important grazing grasses on the Great Plains of Texas and New Mexico, extending into Mexico". Curly mesquite is commonly about the only perennial grass providing forage and soil protection over a large portion of Great Plains grasslands.

The examples in this section were from the Texas West Cross Timbers (Shally Hills range site) which is about the eastern limit of this species that is more typical of the semiarid zone. Erath County, Texas. Estival aspect in moderate drought,Late August.

175. Crawling across the rocks- Asexual (= vegetative) reproduction and the clonal structure of curly mesquite was obvious in this specimen as it sent out stolons and daughter plants over this sandstone. Note also however sexual reproduction by production of grain: "seed stalk" (culm with the fascicle arrangement of spikelets) in right foreground.

Erath County, Texas. Estival aspect in moderate drought, late August.

176. Curly mesquite runner- This stolon of curly mesquite had four daughter plants developing at nodes of the shoot. Curly mesquite is a clonal organism in which the genetic individual (the plant of an individual genotype) is the genet (= ortet) and the new daughter or sister plants are ramets (= modules) of the genet. Essentially all perennial plants are clonal organisms, but the new clones (modules or rametas) are very obvious-- hence the concept of clonal organization readily understood-- in sod-forming shortgrass species like curly mesquite and buffalograss.

Stolons are extravaginal shoots. They are secondary shoots arising out of the parent shoot (itself a secondary shoot-- as distinguished from the primary shoot that originated from the embryo asexual generations previously). In extravaginal shoots (which also include rhizomes) the new secondary shoots pierce or come up through the sheath, an organ of invaginated tissue (hence these piercing shoots are extravaginated). Intravaginated shoots are those which grow upward inside of (rather than piercing) the sheath. Intravaginal shoots are labeled tillers. Grasses whose secondary shoots are intravaginated (ie. tillers) have a tufted or cespitose growth form and are called "bunchgrasses". This is in contrast to "sod-forming grasses" like curly mesquite. (Some grasses like Indiangrass and many of the bluestems have both tillers and extravaginal shoots, especially rhizomes.)

Stolons and rhizomes are more effective than tillers in invasion of new ground by the genet (genetic mother plant). Said another way, extravaginal shoots are more efficient propagules for populating a plant's "resource frontier".

Erath County, Texas (Western Cross Timbers), Texas. Late August.

178. Curly mesquite spikes- Various portions of curly mesquite inflorescences were displayed for today's lecture. The infloresecence of curly mesquite (all Hilaria species for that matter) is a spike, an unbranched flower cluster-- the inflorescence-- in which the spikelets are sessile--without a pedicel or not pedicellate-- on the rachis. The rachis of curly mesquite is one of the most distinctive of any species of North American grass. It forms a right angle zig-zag pattern known to rangemen as the "crankshaft rachis".

Hilaria spikelets are arranged in fascicles, clusters or bunches, each of which (and each spikelet within which) is sessile. There are characteristically three spikelets per fascicle (two lateral spikelets, both of which have several florets that are each staminate, and a single central spikelet which is one-flowered and perfect).

Inflorescences in the second photograph were in various stages of maturity, including one that was immature (green).

Erath County, Texas. Late August, and after recent rains.

179. A midgrass amid shortgrasses- Some plants of Arizona cottontop (Trichachne californica= Digitaria california) growing among plants of blue grama (dominant) and buffalograss (associate) on the Southern High Plains (Staked Plaind= Llano Estacado). This bunchgrass is a midgrass species along with sideoats grama and western wheatgrass, Adult height of this midgrass was presented with shortgrasses, with which it is most frequently associated on the High Plains, for comparative purposes.

Arizona cottontop--the specific epithet is a commenrative name for Baja California (Barkworth et al., 2003, p. 368)-- is a decreaser that is frequently a major forage species on the mixed prairie. It is especially abundant and valuable in direr parts of the semiarid zone. It is also an important (locally dominant) climax grass on some ranges in the Chihuhuan Desert and, especially, the Sonoran Desert. In addition to standard treatments in the general literature both old as, for example, the Range Plant Handbook (Forest Service, 1940, ps. G122-123) and new as in Flora of North America- Poacaeae, part 2 (Barkworth et al., 2003) some of the most thorough descriptions have been those by Cable (1971, 1979), especially the former that was nearly monographic in coverage.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and grain-ripe phenological stage(s).

180. Cottontop is tops- Examples of the habit of striking features of Arizona cottontop at phenology of grain-ripe and peak standing crop. Specimens presented here were at end of one of the wettest growing seasons in years on the Llano Estacado and demonstrated the remarkable production of native grasses that occurs under such ideal conditions. Although Arizona cottontop is highly productive (in reference to its niche and production therein) it is most palatable when growing and does not "cure on the vine" (retain nutritive value in dead herbage) to the degree that associated grasses like buffalograss and blue grama do. As a deed- rooted perennial this midgrass member of the Paniceae (panicgrass tribe) is one of the most rapidly growing grass species in the spring.

This is not what most plainsmen mean when they speak of "tall cotton" in that part of the Southern High Plains which is one of the greatest cotton-growing areas on Earth. In a bowdlerized version of one of their colorful expressions, stockmen and other admirers of Great Plains grasslands are defecating "in tall cotton" when their stewartship permits Arizona cottontop like this to flourish on their ranges.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; peak standing crop and grain-ripe phenological stage(s).

181. Emphasis on inflorescence- Two views of the inflorescence and the pubescent spikelets of Arizona cottontop to feature the general appearance and morphology of this panicoid species. With secondary branches coming off of the central axis of the flower cluster this overall inflorescence type (likemost others of the Paniceae) is a panicle, but the panicle branches were described by Hitchcock and Chase (1950, p. 570) as "slender erect or ascending racemes". Such a panicle of racemes is an unusual arrangement.

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; grain-ripe phenological stage.

182. Cotton in the tops- Basis of the common name "cottontop" is derived from the silky or cottony (and usually whitish) pubescence on the florets of the paired spikelets. Arizona cottontop generally produces modest to abundant crops of viable grain that are useful for reseeding. Natural Resources [Soil} Conservation Service Plant Materials (often in cooperation with other agencies and universities) have several releases of Arizona cottontop including PMT-389, LaSalle Germplasm, and Loetta. In such matters as reseeding, including selection of adapted species and accessions, the expertise of local authorities (eg. range conservationists, county agricultural agents and area Extension specialists, reclamation workers).

Texas Tech University High Plains mixed prairie unit, Lubbock County, Texas. October; grain-ripe phenological stage.

183. Squirreltail bottlebrush (Sitanion hystrix)- This member of the wheat or barley tribe is generally viewed as an invader or, at best, increaser on most range sites but it grows throughout a vast part of the Western Range including most of the Intermountain Region, Rocky Mountains, and Great Plains. Squirreltail is often common in the sagebrush shrub steppe, semiarid plains grasslands, and mountain grasslands and subalpine meadows. The range of bottlebrush extends from the Pacific slope to east of the Rocky Mountain chain and from British Columbia far down into the western states of Mexico, including Baja California. As might be expected from this great species range several varieties or subspecies of this species have been recognized. The awns of squirreltail have sometimes proved to mechanically injurious to animals, but generally this has been more nusiance than anything.

184.   Silver bluestem (Andropogon saccharoides= Bothriochloa sacharoides= B. laguroides subsp. torreyana) at anthesis - This midgrass is typically an increaser on most mixed prairie range sites and an invader on tallgrass prairie range sites, but it is a decreaser on some range sites in drier parts of mixed prairie, the arid semidesert grassland, or shallower sites in the western Edwards Plateau adjoining the Chihuhuan Desert.

The conflicting interpretation of seral versus climax status of silver bluestem as well as varying descriptions of role and dominance this species in mixed paririe was presented below under Staked Plains mixed prairie. Stated summarily for general, across-the-board purposes and especially for lay audiences, silver bluestem (silver beardgrass) is an increaser when viewed "on average" over the extent of its biological (species) range, but for precise pruposes and in more scientific contexts successional (disturbance) status of silver bluestem is range site-specific such that this species is alterntively decreaser, increaser, or invader depending on the particular range habitat on which it is growing. While silver bluestem has often been regarded as a mid-seral species (Nofal et al., 2004), which equates to increaser in response to overgrazing, Clements (1920, ps. 132, 133, 134, ) and Allred (in Weaver and Albertson, 1956, ps. 270-272) interpreted silver bluestem as a decreaser and local climax dominant on certain grassland environments in the Great Plains, especially southern parts of the High Plains. In the semidesert grasslands Desert Plains) Clements (1920, ps.144, 146) interpreted (in his monoclimax model) little bluestem, silver bluestem, and sideoats grama as subclimax dominants" in the climax Aristida-Bouteloua Association. Later he (Clements, 1920, p. 323) cited results where other workers in the Sonoran Desert had obtained satisfactory results in range restoration by reseeding moist sites in which silver bluestem (the common names were silver-top or feather bluestem) was sowed along with blue, hairy, and sideoats gramas. Clearly silver bluestem cannot be sowngraded to increaser rank on more xeric range types and site.

In the encyclopedic Flora of North America (Allred in Barkewoth et al., 2003, p. silver bluestem was specified as B. laguroides whereas B. saccharoides has a species biological range farther south. By this latest treatment there is no B. saccharoides in the United States of America. It is all B. laguroides. Erath County, Texas. July.

185. Silver bluestem at peak biomass- Large individual of silver bluestem was at soft dough stage on an Edwards Plateau live oak-juniper mixed prairie savanna at (or near) climax. Another though smaller individual was at left foreground (lower left corner). This is the typical habitat of silver bluestem on mixed prairie.

Texas A&M University System Sonora Experiment Station, Edwards County, Texas. October.

187. Partly in and out of the boot- The four apices of silver bluestem shoots in these two photographs presented four degrees of emergence of the inflorescence (panicle) from the boot. Panicle atop the left shoot in second photograph was fully emerged or exerted. Details of fully expressed panicles were shown in the next set of two slides. West Cross Timbers near end of a summer of severe drought.

Erath County, Texas. September, emergence of inflorescence from boot.

188. Silvery spectacle- No, not necessarily spectacular but a conspicuous spectacle nonetheless was this appearance of showy inflorescences of silver bluestem in the Western Cross Timbers. Terminology applied to inflorescences of Andropogon, Bothriochloa, Schizachyrium, and Dichanthium species has about as many interpretations as does taxonomy of these taxa. Contemorary description of this inflorescence type is panicle with primary racemose branches (Gould 1975, p. 591; Hignight et al., 1988, ps. 8, 23; Hatch and Pluhar, 1993, p.43). These specimens were growing in the West Cross Timbers near end of a long, hot sumer of severe drought and following two mowings. This species is survivor if given half a chance (come to think of, even if not given half a chance).

Erath County, Texas.September, fully emerged inflorescence, at 1) pre-anthesis stage (first photograph) and 2) early dough stage (second photograph).

189. Buffalograss- The quintessential shortgrass species in full bloom (staminate inflorescences)- Buffalograss is the co-dominant with blue grama over much of the Great Plains region, especially the potential natural vegetation of the semiarid central grassland domain identified as "Grama-Buffalo Grass" (K-65 in Kuchler, 1964; K-58 in Kuchler, 1966).

It was described above when introducing blue grama that this cespitose (bunchgrass) species and buffalograss are co-dominants yet blue grama is considerably more drought tolerant than buffalograss. During recovery from drought the stoloniferous buffalograss restores its cover faster than the strictly tiller-producing blue grama. The affilitation, interaction, and response to drought of buffalograss and blue grama were chronicled by Weaver and Albertson (1956, ps. 33, 79, 104,133, 149-150, 253-254.

As with blue grama, buffalograss has received treatment in all of the major taxonomic and ecological works, both scientific and lay publications (and those in between).

Erath County, Texas, May.

190. Shooting up shoots- A plant of male buffalograss with numerous sexual shoots (staminate shoots in case of this male plant). This dioecious species reproduces both sexually and asexually, this latter mode mostly via stolons although rhizomes are produced infrequently. The clonal characteristic of buffalograss is pronounced with sizeable areas (often measured in hundreds of square yards) of the soil surface covered by a single plant. Adventituous rooting at nodes along stolons gives rise to many "daughter" or "sister" plants (modules, ramets, or clones) of the original parent or "mother" plant (the unique geontype). Each of these modules in turn gives rise vegetatively (asexually) to still more modules or clones (=modular or clonal plants) each of which can send up sexual shoots of the same same sex as the genotype (ie. many staminate or pistillate shoots per module) of each individual of this dioecious species.

Erarth County, Texas. May; anthesis.

191. Male buffalograss- Buffalograss is regarded as being either monecious or dioecious. If the latter is the case then the specimen in this slide is a staminate plant, but either way the inflorescences are staminate. A stolon or runner was presented in the lower left foreground to illustrate asexual reproduction along with the sexual mode. Buffalograss is one of the best examples with which to illustrate the phenomenon of a clonal organism. Each of the nodes along the stolon can produce a new daughter plant thus making the older clonal unit the mother or parent plant.

Tarleton State University Hunewell Ranch, Erath County, Texas. May.

192. Study of a buffalograss ramet (and of photographic light)- Paired photographs of a vegetatively reproduced unit (a ramet or clone) of a genetic individual (genotype) of buffalograss. This pair of photographs (one on left was in full-sun; one on the right was under overcast sky) presented certain features with more clarity in either full-light or some degree of shade. This paired comparison was study of lighting conditions for revealing photography as well as the primary objective of showing a dominant shortgrass species.

Erath County, Texas. October; anthesis.

193. Clonal unit of buffalograss- Sexual shoots fully emerged on one vegetative unit (a clone) of male buffalograss. Sexual and asexual reproduction were both presented in these two photographs. Buffalograss typically blooms in both mid-spring and mid-autumn, but it is opportunistic and reproduces sexually when growting conditions (especially soil moisture) permit. (Note the various months of blooming represented by various photographs in this section.)

Erath County, Texas. October; anthesis.

194. Staminate flower clusters of buffalograss- Views of male inflorescences of buffalograss that developed in late summer in response to the blessings of good rains that fell in late summer and with above average temperatures.

Tarleton State University College Farm, Erath County, Texas. September, late summer.

195. Bull buffalograss in rut- Anthesis in staminate flowers of buffalograss. Like most of the native grasses of the semiarid plains buffalograss has to be opportunistic, especially with regard to sexual reproduction. The male inflorescences presented here and in the preceding slides were blooming in late summer following recent rains.

First photograph: Erath County, Texas, May. Second photograph: Tarleton State University College Farm, Erath County, Texas, September, late summer.

200. Springing forth-Young spring stolons of buffalograss with typical coloration of early growth and arrangement of leaf axils on shoots.Stolons are aboveground intervaginal (piercing of leaf sheath) shoots. All intervaginal shoots, of which there are two types in grasses (rhizomes being the other), are horizontal. This is in contrast to intravaginal shoots (= tillers) that grow vertically and up through (rather than peircing) the leaf sheath.

Tarleton State University College Farm, Erath County, Texas. Late Apri; vigerous spring-growth (shoot elongation stage).

201. Surviving drought on the Great Plains- Several plants (or modules,clones of the same genetic individual) of buffalograss undergoing drought stress in early spring. It is usually assumed that nonwoody grasses (ie. all but bamboo) do not have aboveground perenniating parts; that is, all shoots are only annual organs that die at end of the annual growth cycle. This is mostly true, however some species like buffalograss have shoots that sometimes live for two or even three years with periodic bouts of dormancy. Drought and temperatures below the critical temperatue are two dormancy inducers.

The shoots (culms and leaves) of the buffalograss presented here had some parts that were apparently dead and others that were obviously alive. It provided a good example of the "Is it alive or dead?" state of this eragrostoid species. Clearly this is a survival adaptation for grass life on the plains. A dramatic lesson if life, especially for such a short plant.

Central Plains Experiment Station, Washington County, Colorado. Late June: drought-stressed.

202. "Cured on the vine"- A combination of small, fine leaves tht tend to retain the nutritive content, dry winters in the semiarid zone with limited moisture to leach out nutrients in plant tissues, and stolons that can live for more than one growing season (or year) result in dry, brown, and apparently "dead" (or nearly so) buffalograss shoots (stolons) that are remarkably nutritious and palatable in winter (or whenever dormant). This phenomenon of self-cured, dried herbage of remarkable high nutritive value on the Great Plains (even in winter) was recorded (with reliance on written correspondence) in one of the enduring classics of the Western Range livestock industry: Trans-Missouri Stock Raising The Pasture Lands of North America: Winter Grazing (Latham, 1871; reprinted with an introduction by J.C. Dykes, 1962, ps. 15-21, 78, 80,81, 86). A few excerpts included: "... the grasses cure on the ground without losing any of their nutriment..." (p. 18), "... subsisting upon the natural grasses of the country, in the winter as well as summer; no preparation of hay or other food is necessary" (p. 78), and "[t]he grasses are highly nutritious, cure on the ground, remain as permanent food during the entire winter..." (p.80).

Of course the Great Blizzard of 1886 ended the "no hay-era" when snow and ice covered the shortgrasses (made shorter still by overstocking) terminating in the great "die-ups", but that disaster bred out of ignorance, glib optimism, and greed did not negate the fact that when herbage of range grasses, like buffalograss, was available it retained its nutritional quality even in winter.

Las Animas County, Colorado. Late June: atypical stage of growth due to drought dormancy.

205. Wolftail (Lycurus phleoides)- Wolftail (literal translation from the Greek base, Lycurus) is in the Aveneae (oat or, sometimes, timothy) tribe. In fact, wolftail has the less-used common name of Texas timothy. The infloresence is a contracted panicle. This perennial bunchgrass has shoots that have been described as "semiperennial" (Forest Service, 1940, G77), the phenomenon in which the tillers frequently proceed only to partial dormancy and death during winter therby allowing rapid spring green-up with onset of rains and warmer temperatures. Similar phenological responses occur in buffalograss and blue gramma, two associated species on the plains grassland and southwest pine forests in which these species occur. All three species possess the desired forage feature of curing at a relatively high state of nutritive value (ie. the capacity to "cure on the vine" discussed above). (Of course gramagrasses and buffalograss are eragrostoid while wolftail is a festucoid grass.)

The specimen photographed here was part of the understorey of a juniper woodland in the Mogollon Rim country of central Arizona (Yavapai County). Mid-June of a dry spring and before onset of summer rainy season, but in worst drought in Arizona history (exceptional drought). The "semiperennial" condition of wolftail tillers (bluish gray color) was visible in both slides.

Examples of purple threeawn (Aristida purpurea) from disturbed ranges of tallgrass prairie were presented here as examples of plants in this widespread taxonomic complex (explained in the next photo-caption). Following samples of purple threeawn from the tallgrass region examples from the mixed prairie and shortgrass plains were introduced.

Successional ranks (statuses in response to range distrubance, especially overgrazing) of Aristida species, and in particular the various taxonomic forms (varieties or whatever) of A. purpurea, remain incompletely understood and a topic of continuing controversy. It is "textbook knowledge" that threeawns are invaders on most North American grasslands and, except in rare instances, of other biomes (presence of Aristida species on desert and southern pine forest ranges are notable exceptions) Threeawns are "textbook examples" of plant indicators of severe range disturbance and deterioration (improper grazing management, tillage and subsequent abandonment of cropland, "cut-and-run" logging) such that various species of threeawns or wiregrass are abundant and widespread on overgrazed ranges, old fields ("go-back land"), and cutover forests.

This generalization is adequate for basic textbooks (at least some of them), Agricultural Extension fact sheets, conservation agency brochures, and ranchers' guides. Beyond these, however, the successional meaning and even practical importance of threeawns on grassland ranges is far from clear or straightforward. One of the common observations in plant succession and development of range vegetation is that species that tend to increase on or invade disturbed plant communities (=abused or degraded ranges) in humid and subhumid regions frequently dominate ranges in climax or high seral stages (and decrease or even disappear from these same ranges when they are severely disturbed) in semiarid and arid regions. In other words, range plant species that are decreasers in more xeric (and otherwise harse) range environments are increasers or invaders on range habitats found under more mesic (less severe or more moderate or amenable) conditions. A number of the Aristida species appear to show such responses.

Clements (1920, ps. 115, 119, 121) interpreted A. purpurea (or equivalent Aristiada species) as potential natural dominant species along with little bluestem, sideoats grama, and certain needlegrasses in the general or regional Stipa-Bouteloua Formation, including the portion of tallgrass prairie (the Andropogon associes in context of monoclimax theory) therein. While he noted that Aristida species were some of colonizers or early invaders on overgrazed grasslands and abandoned fields he also explained that A. purpurea was an associate of buffalograss, galleta, and tobosagrass in the Staked Plains of Texas and a species associated with blue and black gramas in the Chihuhuan and Sonoran Deserts of New Mexico and Arizona (Clements, 1920, ps. 142, 144). Clements' Desert Plains climax grassland (known currently as semidesert grassland) was the Aristida-Bouteloua Association in which there was a consociation (a climax unit comprised of a single species-dominant) each for A. purpurea, A. californica, A. arizonica, and A divaricata as well as consociations of bush muhly along with those of black, blue, sideoats, Rothrock, and hairy gramas.(Clements, 1920, p. 145 and still more on 146-148).

Conversely, Clements (1920, ps. 95, 140) also recognized that Aristida species did invade overgrazed grassland and abandoned cropland. Perhaps the observations and descriptions of Clements (1920, above cited pages) are consistent with and even serve as an exampe of patch dynamics. If this was the situation, certain Aristida species such as purple threeawn would serve as early invaders of disturbed patches (overgrazed spots for example) with presence of this species reflecting (indicating) disturbance gaps in the grassland sward. Even if that explanation is correct it remains only a partial explanation. Given that Clementsian consociations were units of climax vegetation (vegetational components of an association, an association comprised of a single dominant species), species that formed consociations had--by definition--to be climax and therefore correspond to decreasers and certainly not invaders.

Organization Note: Viewers can read in Literature Review (Range Type section or heading, Historical Note: "Founding Fathers" of Range Management subheading thereunder) where the Dykersterhuis (1949) decreaser-increaser-invader model was derived in large measure from the plant indicators concept of Clements(1920, especially Section VI. Grazing Indicators, ps. 270-335). Therein it was noted that it was Plant Indicators that provided the germ of the Dyksterhuis (1949) categories of decreasers, increasers, and invaders in the concept of seral types as grazing indicators.

206. Perennial threeawn (Aristida purpurea) on deteriorated tallgrass prairie range - What is most likely "purple threeawn" was thriving and adding spring color to an area heavily impacted by motor vehicle traffic.This was typical "prime habitat" for threeawns which are some of the most abundant perennial grasses on the most abused areas (eg. sacrifice areas, "stomp lots", ranch roads). The other most common species on this deteriorated site was the naturalized alien, rescue bromegrass. The threeawns or "wiregrasses", as they referred to in the southeastern pine forests, are typically classified successionally as invaders. As a general rule Aristida species are characteristic of vegetation at some stage of retrogression and therefore indicator plants of deteriorated ranges (or regenerating pine forests in less advanced seral stages). One of the general features of species responding as ecological invaders is low feed value. This is most pronounced in annual species, but some perennial species (in fact, entire genera) have this feature. Aristida is one of these (with some rare exceptions). In fact, there is a high proportion of Aristida species that are annuals, even short-lived annuals known as ephemerals.

As if all this were not enough, Aristida includes several taxa that are a taxonomist's worst nightmare. Some of these integrade or hybridize (or whatever grass plants do "to make life harder for agrostologists") with the result that various authorities have interpreted such taxa as species, subspecies, and varieties in different ways which has led to confusion and frustration (especially because the taxonomic arrangements seem to change with every new treatment of Aristida). The term that has often been invoked in describing and arranging these taxa into groups is "complex". An example of such includes such closely related and intergrading threeawns as red threeawn (A. longiseta), purple threeawn (A. purpurea), wright threeawn (A. wrightii), roemer threeawn (A. roemeriana), and a few others depending on which of these species grow in association in any given geographic location. In Texas the complex is often known simply as "perennial threeawn" or, sometimes, "purple threeawn" after A. purpurea which is viewed as the species, with what have previously been interpreted as separate species ranked as varieties therein. Thus "perennial or purple threeawn" includes A. purpurea var. longiseta, A. purpurea var. purpurea, and A. purpurea var. wrightii. Other agrostologists still designate these threeawns known by the various common names as separate species. There was bound to be some sort of lesson in this example of "where the experts cannot agree".

208. More sun-faded than red (but alive)- Two plants of red threeawn (Aristida longiseta) on mixed prairie during a bad drought. Almost miraclously these two individuals were still alive and growing albeit it slowly. A. longiseta is the dominant threeawn or wiregrass over most of the mid- and shortgrass range of the Great Plains (Weaver and Albertson, 195.p, 41-43). What has traditionally been regarded as red threeawn has a biological range extending throughout the Great Plains and parts of the western Central Lowlands physiographic provinces as far north as the Canadian Prairie Provinces. This species also grows throughout much of Arizona and southeastern California, including the Sonoran Desert. (An example of red threeawn in the ponderosa pine forest range above the Sonoran Desert was presented in the chapter, Southern and Central Rocky Mountain Forests). Red threeawn has an amazing species range and degree of adaptation.

The Aristida species are a taxonomist's nightmare. The genus have been reinterpreted at various times. The most recent--and probably the official treatment for decades-- was that of Barkworth (et al., (2007, ps. 330-334) in which red threeawn was regarded as merely a variety of purple threeawn (Aristida purpurea): Aristida purpurea var. longiseta. What do you bet that this is not the final word either? Iin this new taxonomic treatment the traditional purple threeawn became A. purpurea var. purpurea. Other varieties in what was now termed the "A. purpurea complex" (Barkworth et al., 2007, ps. 330-334) included Fendler's threeawn ( A. fendleriana) which became A. purpurea var. fendleriana. Fendler's threeawn was presented and covered below.

Rnge Plant Handbook (Forest Service, 1940, p. G20) provided its typical concise yet thorough discussion, including practical considerations, of red threeawn.

Las Animas County, Colorado. Late June.

209. Reflecting sunlight to the namesake color- Specimens of red threeawn (A. longiseta) on a disturbed postclimax tallgrass prairie. On former tallgrass prairie in the Nebraska Sandhills herbiverous activity of black-tailed prairie dog (Cynomys ludovicianus) degraded the range into a patch of Eurasian weeds with red threeawn about the only perennial grass species still present. Some of those specimens, including the pretty individuals shown here, served as good examples of their species. (The case of prairie dog degradaation of tallgrass prairie was included in the chapter entitled, Tallgrass Prairie [Interior].)

Traditionally all of the Aristida species, including A. purpurea and A. longiseta, have been classed as invaders throughout the tallgrass through to shortgrass prairies. This is probably--perhaps definitely--an oversimplification that is frequently in error. Certainly these are relatively unpalatable species such that under heavy use, and even more so under overgrazing, persist after palatable species (hence, decreasers and increasers) have declined or disappeared. So far, so good. However, on mixed prairie these Aristida species recover from disturbances such as drought much like palatable short-and midgrass species (Weaver and Albertson, 1956, ps.143, 150). Likewise, Weaver and Albertson (1956, p. 213) reported that purple threeawn was less resistant to drought, a characteristic shared with tallgrass species (and not a feature characteristic of invaders). They also reported that A. longiseta was abundant on mixed prairie on the Colorado Piedmont where blue grama was dominant, in the blue grama-buffalograss shortgrass type, as a dominant midgrass species in the intermediate wiregrass type, and as an important species with the tallgrasses (including sand bluestem and prairie sandreed) in the bunchgrass type all in Colorado (Weaver and Albertson, 1956, p. 233, p. 241, p. 244, p. 246, respectively). Also in Colorado, red threeawn was associated with western wheatgrass and needle-and-thread on excellent shortgrass range dominated by blue grama and buffalograss (Weaver and Albertson, 1956, p. 255). All-in-all this is not the response or "friendships kept" by invaders, at least not on mixed prairie. It is quite another thing on tallgrass prairie as shown here on a prairie dog town on depleted postclimax tallgrass range.

Fort Niobrara National Wildlife Refuge, Cherry County, Nebraska. Late June; peak standing crop, soft dough phenological stage.

210. Fendler's threeawn (Aristida fendleriana= A. purpurea var. fendleriana)- A local stand of Fendler's threeawn on go-back land. Most Aristida species are invaders with disturburbances being the conditions under which most threeawn individuals grow. Notwithstanding this situation, Fendler's threeawn is widely distributed and adapted to a variety of conditions ranging from alpine to southwestern desert to old fields of the Great Plains (Silveus, 1933, p. 338; Forest Service, 1940, ps. G19-G20; Hitchcock and Chase, 1950, ps. 476-477; Gould, 1975, p. 400; Barkworth et al., 2003, ps. 332, 334). An example of a stand of this species on an old field in the Staked Plains was shown here.

Fendler's threeawn has been treated variously by various authors (discussed in the next caption) perhaps because it is a variable taxon (whether regarded as species or variety). It is frequentlly distinguished by a pronounced "pin cushion" form of basal leaves, but this is not consistent as Fendler's threeawn is similar (and sometimes confused) with red threeawn (A. longiseta= A. purpurea var. longiseta) or other taxa in the A. purpurea complex (next caption). One of the most obvious features of Fendler's threeawn--in addition to shorter awns (Allred, 1984, p. 393-394; Powell, 2000, p. 252) and solitary spikelets (Silveus, 1933, p. 337--is the overall short stature of individual plants of this species. In the extensive stand presented here there was not one plant over ten inches tall and most individuals were only five to seven inches in height. A. purpurea var. longiseta, which is extremely variable, has some individuals with heights as short as A. purpurea var. fendleriana (Allred, 1984, p. 393-394), but again the relatively shorter awns coupled with basal leaves and generally short stature distinguished plants presented here as Fendler's and not red threeawn.

Lubbock County, Texas. October. Fruit-ripe stage.

211. Sundown on Fendler's threeawn- The right light at the right time for the right species is one of the secrets to plant photography. "Fools luck" in this case was responsible for this photographer capturing Fendler's threeawn near sundown when long shadows luckily caught the distinctive awned appearance and general morphology of this High Plains species of Aristida. Aristida is one of the Gramineae genera that is generally an agrostologist's nightmare. Luckily (again for this author) A. fendleriana, with its short basal leavesand generally short stature, is one of the more easily identified species in a genera filled with contradictions and taxonomic complexes.

This is also one of the Aristida species that has consistently (more-or-less) been recognized by the various agrostologist specializing in this problematic genus. A. fendleriana has been ragarded as a "traditional species" (though "somewhat weak and controbersial") according to Powell (2000, p. 250). Recent work, especially by Allred (1984), resulted in reinterpretation of this taxon as another variety of the A. purpurea complex. This work was retained by the encyclopedic Flora of North America- Poaceae, part 2 (Barkworth et al., 2003, ps. 332, 334) in which the treatment of Aristida was by Allred. Either way, anyhow, etc., the taxon that still bears fenlderiana (somewhere) is interpreted as existing. It was shown here.

In the Range Plant Handbook the Forest Service (1940, ps. G19-G20) noted that this species (as interpreted therein) was also called "small triple-awn" and by stockmen as "no-eat-um-grass". Not only is this species fairly unpalatable but it produces even less forage than other associated three-awns. One of these associated (and closely related) Aristidas is A. longiseta or, in latest treatment, A. purpurea var. longesita from which A. purpurea var. fendleriana is distinguished by the much longer awns in longiseta. Essentially all of the taxonomic treatments cited herein (Silveus, 1933, p. 338; Forest Service, 1940, ps. G19-G20; Hitchcock and Chase, 1950, ps. 476-477; Gould, 1975, p. 400; Allred, 1984, ps. 393-394; Barkworth et al., 2003, ps. 332, 334) to some degree or the other indicated the short stature of this taxon compared to others in the A. purpurea complex with which it is closely related and morphologically similar to.

Lubbock County, Texas. October. Fruit-ripe stage.

212. One of the lowest and the lowliest- Hairy tridens (Tridens pilosus= Erioneuron pilosum) is a one of the few species of native, perennial grass that is almost always an invader no matter what range site it occupies. This low-growing species comes in (sometimes as a local dominant) of some of the most abused ranges and the harshiest of habitats. It is also one of those species for which the agrostologists cannot decide on its one correct (or most nearly correct) scientific name. In fact, they cannot even decide on its standard common name. Several of the various agencies of the United States Department of Agriculture showed the stupidly duplicitous common name of "hairy woollygrass". Why not "wooly woolygrass"? That would be more poetic; at least it it would not confuse two types of pelage. A literal interpretation of erion is Greek for "wool" and, of course, pilosus, pilosum, etc. is Latin in reference to "hair", or "or hair". Hence "hairy woolygrass". This, however, an example where literal translantion from one language to another results in nonsense, awkward, or downright stupid verbage; a logical extension beyond what is rationale, tasteful, or even meaningful. It is an example that the only trully universal scientific language is mathematics.

Hairy tridens is common--under disturbance--on tallgrass, midgrass (mixed), and shortgrass prairies as well as on pinyon-juniper woodland range. The specimen shown here was growing on an overgrazed range of disturbed tallgrass Grand Prairie. This individual was larger than most plants on mixed prairie or the shortgrass plains.

Erath County, Texas. April. Soft-dough stage.

214. Hairy tridens in the shortgrass country- Previous examples of hairy tridens were taken from disturbed areas on tallgrass prairie. This specimen was growing in the heart of "shortgrass country" and was included to present an example from some of its other preferred habitat where it kept company with buffalograss and blue grama. This shortgrass species is usually classified as an invader on most range sites. It is most common on overgrazed range or otherwise disturbed land (eg."go-back land") on tallgrass, mixed, and shortgrass (plains) prairies, but here on the shortgrass plains it was right at home where it can be an increaser depending on the range site.

Palo Duro Canyon State Park, Randall County, Texas. June.

215. Showy interloper on the sea of mixed prairie- Robust plant of the Eurasian, annual bulbous bluegrass (Poa bulbosa) that invaded a locally disturbed patch in the sward of a mixed prairie range in "mint condition" (Excellent range condition class; SRM 608) that was dominated by needle-and-thread, blue grama, and western wheatgrass. Bulbous bluegrass is sometimes a short-lived perennial (on some parts of California having Mediterranean climate), but it is a cool-season annual throughout the Great Plains and Intermountain Region. The competitiveness of this aggressive invader on disturbed sites and microsites was shown by presence of this species on a mixed prairie at climax except for local spots of disturbance the cause of which was unknown..

Niobrara County, Wyoming. Late June: peak standing crop at grain-shatter stage of phenology (and death of plant= completion of life cycle in an annual species).

217. Eye-catching panicle of a noxious species- Details of panicle of the Eurasian bulbous bluegrass. This was a close-up view showing spikelets in one of the panicles on the plant above the caption before last (two slide-set).

Niobrara County, Wyoming. Late June: grain shatter stage.phenology

218. Threadleaf sedge (Carex filifolia)- Threadleaf sedge is probably the single most abundant and important Carex species on North American ranges, at least in the continental interior. It is also one of the most widely distributed with a species range from the Yukon Territories to Texas and from the Pacific Slope east to Labrador (Forest Service, 1940, GL5; Fernald, 1950). Not only is threadleaf sedge valuable for grazing (Fair to Good forage value), it is also invaluable for prevention of soil erosion in the windy, semiarid Great Plains and in northern portions of the Central Lowlands. A good general reference for C. filifolia is (Hurd et al., 2998, ps. 112-113).

The plants presented in these and the next two photographs were taken on the "mint condition" (Excellent condition class) needle-and-thread, blue grama, and western wheatgrass-dominated range in the Central Great Plains that was featured earlier in this chapter (above). Threadleaf sedge and Indian riecgrass were associate range plant species on this range. Niobrara County, Wyoming. Late June; peak standing crop at mature fruit stage.

219. Shoot apices of threadleaf sedge- Sexual shoots (first photograph) and inflorescences, entire and fruit-ripe stage, (second photograph) of threadleaf sedge growing on an Excellent condition class range in Central Great Plains in which this species was an associate (along with Indian ricegrass) to needle-and-thread, blue grama, and western wheatgrass.

Niobrara County, Wyoming. Late June; peak standing crop at mature fruit stage.

220. Scarlet Globemallow (Sphaeralcea coccinea)- This member of the Malvaceae (mallow family) is often the most abundant forb in western portions of the mixed prairie and on into the shortgrass plains. There appears to be some dispute as to the forage value of this forb. It was described by the Society for Range Management Intercollegiate Range Identification Contest committee (Stubbendieck et al., 1982) as having but fair to almost no palatability, but in a later edition the committee (Stubbendieck et al.,1992) described it as excellent for native small ruminants. Hermann (1966) reported forage values ranging from poor or none to good. Observations by New Mexico workers on the blue grama ranges of the Ft. Stanton Experimental Ranch suggested that scarlet globemallow was quite palatable not only to forb-preferring animals like sheep and mule deer but also to cattle (specifically large stocker steers). Either (or any) way it is one of the more common forbs on plains and mesa grasslands.

Guadalupe County, New Mexico. June.

221. Broadleaf milkweed (Asclepias latifolia)- This is one of the more than two dozen species of Asclepias growing on the prairie and plains grasslands of the continental interior. It is one of the more common milkweeds on the Great Plains grasslands. There is amazing variation in the morphological features and preferred habitats of Asclepias species. One of the most obvious differences among milkweed species is in their leaves. Kingsbury (1964, p. 267) used the two divisions of: 1) narrow-leaved milkweeds (having "linear or narrowly lanceolate leaves") and 2) broad-leaved milkweeds ((usually greater than 1.5 inches wide over "much of their length"). Broadleaf milkweed is the accepted or preferred common name for A. latifolia which should not be confused with the general category of "broad-leaved milkweeds". Broadleaf milkweed was listed by Burrows and Tyrl (2001, p. 126) as one of 16 Asclepias species that are "particularly important toxicologically". The "poisonous principle" (ie. the toxin) is a group of organic compounds known as cardenolides which manifest themselves within the gastrointestional tract as well as by bleeding in trachea, lungs and the heart surface (Burrows and Tyrl, 2001, ps. 131-135).

***Note to beginning range students: While livestock losses due to poisonous plants may not be one of the major sources of losses industrywide, the importance to indvidual stockmen can be (often is) staggering. Like damage inflicted by predators, poisonous plant losses capture the attention, imagination, anger, and political action of livestock producers. Range Management professionals who work closely with stock-raisers (eg. Agricultural Extension agents, federal range conservationists, and agro-chemical product salesmen) should thoroughly familarize themselves with the fundamentals of the poisonous range plant problem. In range areas having histories of livestock losses (this includes any number of syndromes of lowered animal performance in addition to outright animal death) the range practitioner should cultivate a sound professional relationship with a veterinarian knowledgable in the field of poisonous plants. The earliest Range Management textbooks (eg. Sampson, 1923) included extensive coverage of the poisonous range plants. Most of the Agricultural Experiment Stations in the Western Range states published bulletins on poisonous range plants early in the history of these organizations which, as mandated by the Morrill and Hatch Acts, kept a close eye out for practical problems impacting ranchmen and farmers. In the context of this aspect of Range Management it is important that those anticipating careers in or closely related to this field learn the poisonous plants in their area. Producers want names (common ones will suffice), and they have great respect for those who can correctly identify the plants causing the stock poisoning.

The milkweed flowers have a unique structure. The petals of the corolla occur beneath a corona that is comprised of five hoods each typically having a beak or crest. Surrounded by the five-part corona is the actual flower or sex organ portion made up of a five-stamen androecium and the compound pistil or gynoecium which adhere to each other. Together the adnated stamens and pistil form a resultant structure called a gynostegium.

Crowley County, Colorado. July.

Man has proved to be one of the most effective plant dispersal agents. For better or worse (often unintentionally for worse) this includes dispersal of diaspores of plants (including bacteria and fungi in the generic sense of plant) that naturalize to become weeds or pathogenic pests. Under certain cropping systems or in some operations certain of these noxious naturalized plants are of value in production agriculture. This is especially the case for Range Management due to the extensive and often opportunistic nature of this ecological-based husbandry. Two common alien weed species of the Chenopodaceae (goosefoot family) that grow on North American range and fall under a general heading of "usually a weed but often a beneficial plant" were included with Great Plains grasslands.

222. Russian thistle or tumbleweed, the "tumblin' tumbleweed" (Salsola kali tenuifolia= S. pestifer= S. tragus= S. iberica)- This plant is not, precisely speaking, a thistle nor is it the only tumbleweed, there being several plant species that blow across the land in a rolling motion following breakage of their basal stem. This species is, however, the tumbleweed unless otherwise specified. Russian thistle is the more commonly used name and the preferred common name. The usual story has it that Russian thistle was introduced into South Dakota from Eurasia in contaminated flaxseed and that after a few decades it had thoroughly naturalized across much of the Western Range (Forest Service, 1940, W. 165). This species is indeed a weed in field crop production, but when young and later when dead and dry (and moistened by frost, snow, etc.) Russian thistle is rated as fair or higher in palatability. Perhaps the greatest value of this tumble weed is reduction of soil erosion by its extensive cover on abandoned farmland ("old fields" in the ecological literature; "go-back land" among rangemen, farmers, stockmen), overgrazed ranges, and oil and gas fields. It also provides cover for smaller species of wildlife such as upland game birds.

Russian thistle may at times be toxic due to either oxalates or nitrate accumulation and when dry it can cause slight mechanical injury by its pointed leaves (see next slide), but overall it is a fairly desirable range forb, especially on severely disturbed lands.

Mitchell County, Texas. October

224. Kochia or summercypress or belvedere (Kochia scoparia)- This is another annual Eurasian chenopod that thoroughly naturalized on the North American Great Plains. Like Russian thistle this development has generally been viewed as somewhat beneficial (perhaps even more so) especially in Range Management, and for the same reasons. The forage value of kochia is good for both livestock and wildlife though it can cause nitate poisoning and other toxicities. The same can be said for most field crops of course. Kochia also provides protection against erosion. Like Russian thistle kochia is a tumbleweed. Shortly after the annual plant dies it breaks near the ground surface and is blown over the land effeciently distributing the gametophytic generation to produce the sporophytic generation in the next growing season. The tumble weeds like kochia and Russian thistle are some of the best examples of wind dispersal (anemochory).

Occasionally kochia has been planted and grown as a forage crop. This was mostly in the Southern High Plains region where kochia was seeded as an annual agronomic crop and managed for high-quality pasture for cattle having high nutrient requirements (eg. developing replacement heifers, lactating beef cows). Sheep and deer also find kochia palatable, often highly palatable at immature phenological stages.As is the case for many otherwise desirable forage species, kochia can be toxic to livestock and wildlife under certain conditions when it accumulates nitrate or by causing secondary (hepatogenic) photosensitization.

The field of kochia shown here was being grown for certified seed to be sold to commercial growers for pasture plantings. Erath County, Texas. May.

228. Why kochia is an effective colonizer- Mature fruit on branches of kochia. The fruits of kochia are utricles, a fruit type characterized as an indehiscent, bladderlike structure having one seed which is loosely enclosed within the fruit wall (Smith, 1977, ps. 66, 311). The utricle is a common fruit type in the goosefoot family (Chenopodiaceae). Even though the fruit of kochia is tiny (as shown by these two photographs taken with a mircrolense), the single dark seed inside the utricle is even smaller. Nonetheless, this is a very effective sexual propagule or germule as this exotic and naturalized species grows to relatively large size (especially for an annual forb) on range, field, and fencerow. More importantly in this context is the effeciency with which this opportunistic, weedy plant pioneers freshly denuded land. Abandoned cropland (old fields or go-back land), overgrazed ranges and pastures, even barnyards and seldom-used corrals are ideal habitat for this colonizing species.

Erath County, Texas. October.

229. Smooth yucca or small soapweed (Yucca glauca)- This is the common species of yucca on the central grasslands from the tallgrass and mixed prairies to the western edge of the shortgrass plains. The sweet flowers are a delicacy to cattle, so much so that presence of flower clusters and seed pods are a giveaway that a range was not grazed when the soapweed was in bloom.

Hamilton County, Texas. May.

230. Prickly poppy (Argemone polyanthemos)- This member of the poppy family is one of the more common forbs on the Southern Great Plains. It grows from the Texas Panhandle to northwestern North Dakota and eastward to the Missouri River in Kansas and Nebraska. Prickly poppy is extremely drought-tolerant as evidenced by this prolific growth during spring-summer of 2002 during the most extreme drought yet recorded for Colorado. It's annual (sometimes, biennial) life cycle enables prickly poppy to take advantage of winter and early spring moisture and avoid the hottest part of summer when evapotranspirtion rates are highest and soil moisture is frequently lowest.

Prickly poppy is an ecological invader and high densities of this species indicate disturbances which can include drought, overgrazing, road construction, and abandoned farmland. Lincoln County, Colorado. June.

232. Canadian or russet buffaloberry (Shepherdia canadensis)- Buffaloberry is one of the more common shrubs in the grasslands of the Northern Great Plains and Columbia Plateau (especially the Interior Northwest portion between the Cascade Range and the nortrern ranges of the Rocky Mountains).It often grows in more protected areas like coulees. Buffaloberry is usually poor to worthless (rarely fair) as browse, but the fruit is valuable in diets of birds. Cardston Municipal District, Alberta. July.

234. Shoot tip of wood wild rose- Here is another detailed view of the famed wild rose of Alberta showing the ripening structures known as "hips". The hip is the tough, round-shaped structure that is surrounding the actual fruits of the rose which are achenes. An achene is a dry, one-seeded indehiscent fruit with pericarp and seed coat separate except where joined at the funiculus. The achenes which at first seem to be "seeds" are inside the hip which at first-flush appears to be the fruit. The hip is not the actual fruit because the seeds are inside the achenes-- making them the fruits-- which are arranged inside the hip. Hips are thus characterized as "false fruits".

Rose hips are often valuable feed for range animals because they contain high concentrations of nutrients. There are numerous Rosa species in North America, including naturalized ornamentals which became noxious pests. Dayton (1931, ps. 46-49) estimated that there were about 55 Rosa species native to "the Western States". He described 16 species of wild rose. The Range Plant Handbook (Forest Service, 1940, B135) described 11 Rosa species. Most of the wild roses provide browse ranked by Forest Service investigators as fair to excellent. Some species, in particular the spineless ones, are subject to severe overuse and eventual overbrowsing. Some wild roses are riparian species and valuable for protection of watersheds and aquatic environments (eg. as regards fish habitat).

Cardston Municipal District, Alberta. July.

237. Sprawlin' in the shortgrass- Plains pricklypear on a locally disturbed microsite on mixed prairie in the Piedmont Plains to the west of the Southern High Plains and east of the Front Range in southeast Colorado. This cactus was growing on a grassland of blue grama, buffalograss, sand dropseed, western wheatgrass, cheatgrass, and silver bluestem. This area was undergoing a relative severe drought and most of the perennial grasses were dormant except for a few stolons on buffalograss and isolated tillers of blue grama. Even plants of plains pricklypear were conspicuously drought-stressed (see next slide).

Las Animas County, Colorado. Late June.

238. Shriveled but still sexy- Two consectuively closer views of parts of the plains pricklypear introduced in the preceding photograph. The first of these two slides featured the extremely shriveled condition of cladophylls (the padlike shoots) of this cactus. This "wrinkled" appearance was due to water loss from the typically succulent, water-storing shoots, one of the most important water-conserving, survival adaptations of this xerophytic species. The extreme condition of water-depravation in this plant was striking.

In spite of this extreme state of water-stress the plains prickly was blooming. It was persistently carrying out sexual reproduction and exchanging gametes to propagate the genes, the funadmental cellular unit of natural selection. Details of sexual reproduction were preented in the second photograph. A ripening berry (the fruit of cactus) produced in the previous year was to the immediate of the newly opened cactus flower (ie. two years and two phenological stages of sexual reproduction were shown in this slide).

Las Animas County, Colorado. Late June.

239 Sex in two kingdoms- Two newly opened flowers on the plant of plains pricklypear that was introduced two captions above. This tough little xerophyte on a mixed prairie range was performing sexual reproduction even under drought-caused water stress so severe that cactus cladophylls were shriveled from water loss As if not to be outdone, two hymenopterans (of a species unknown to this author) were also engaged in sexual reproduction adorned in the simple beauty of a cactus flower. Both plant and animal species were "dutifully" passing on the genes of their respective races to their posterity and to the preservation of biodiversity, structure, and function of this range ecosystem.

Could there be anything in creation that bespeaks better the meaning of life? The Creator Himself must surely have paused to marvel and smile approval on one of the routine miracles in His creation. It also seemed likely that if Charles Darwin had passsed this way he would have penned a note of the survival fitness of these two manifestations of natural selection. Another brief episode on the great grasslands of the continental interior.

Las Animas County, Colorado. Late June.

242. Shootfire, fruits on cholla shoots- The fruit of walkingstick cholla is borne at apex of the fleshy, cylindrical stems of this common (often defining) shrub on the Southern High Plains (Llano Estacado, meaning Staked Plains). In this species of Opuntia the cactus fruits occur in small groups (clusters) in contrast to singularly along shoot tips in pricklypear.

Noland County, Texas. March.

243. A single cholla fruit- One fruit of cholla cactus removed to present details. The cactus fruit is interpreted as a many-seeded berry (Smith, 1977, p. 104). The fruit of walkingstick cholla is armed with short spines and glochids, but these are punty affairs as compared for example to those of many of the pricklypears.

Noland County, Texas. March.

244. Contents of cholla fruit- A fruit of cholla catcus cut open revealing seeds. First photograph was interior of fruit immediately after being cut open (note thichness of the fleshy portion of fruit wall and moist membrane around seeds). Second photograph was interior of fruit 24 hours after cutting open (note shrinkage of fleshy portion of fruit wall and dried membrane surrounding seeds as compared with appearance immedately following opening as shown in first photograph).

Noland County, Texas. March.

250. Just what the grasslands needed: another species of snakeweed (and yellow composite)- Annual or prairie broomweed (G. draculoides). This is one of the most common and widespread composites on both tallgrass and mixed prairies, especially in more southernly locations. The two plants (one entire plant plus half the crown of its range mate) presented here was growing on the Grand Prairie of northcentral Texas, a little bluestem-dominated tallgrass prairie community. Annual broomweed is considerably less widely distributed across the Central Lowlands and Great Plains than is broom snakeweed (McGregor et al.,1977, p. 373), but its species range is more than large enough for rangemen preferring grass over annual, weedy composites. Annual broomweed has a far-flung distribution across Texas which has some of the greatest remaining acreage of mixed prairie range, albeit mostly in Poor and Fair range condition classes.

Annual or prairie broomweed is an early seral stage colonizer (sometimes a pioneer species) of abused land (eg. overgrazed ranges and those recovering from recent drought, go-back land, highway rights-of-way). Thus this annual broomweed is both an indicator plant as well as a protective (as against soil erosion) and facilitative species that enhances plant succession.

Erath County, Texas. October; full-bloom stage.

251. More yeller flowers- Closer-in views revealed an "ocean" of yellow flowers in part of one annual broomweed. Multiply this fraction of one plant times millions of other plants and it takes no imagination to understand why abused ranges--including those just recovering from extreme drought--look more like rape and canola fields than prairies.

G. draculoides is in the Astereae (aster tribe) of the Compositae.

Erath County, Texas. October;

Staked Plains Mixed Prairie- The following series of slides of range vegetation and plants were taken on the Muleshoe National Wildlife Refuge in early October and showed the early autumnal aspect of the general range ecosystem representative of the natural climax grassland (mixed prairie) of the Southern High Plains (Llano Estacado) of the bluestem-grama range type (SRM 714). The examples of range plant communities presented varied in range condition class from local relicts of Excellent to overall low Good down to high Fair. Most of the plant species and individual plants in this range vegetation had recently become dormant (early dormancy stage of phenology), but some of the latest-maturing, late summer/autumn-blooming species were at peak standing crop and full-bloom to fruit-ripe phenology. Cool season species such as western wheatgrass had been normant for several months and were "thinking about" initiation of new growth for their next growing season. The ever-changing range.

The major range site represented below was Mixed Land which according to the Soil Survey of Bailey County, Texas (Soil Conservation Service, 1963, ps. 39-40) was a blue grama-sideoats grama-lLittle bluestem-plains bristlegrass-Arizona cottontop range plant community. Although the SCS (1963) Soil Survey clearly listed little bluestem as the dominant decreaser it is almost 100% certain that it is silver bluestem and/or cane bluestem and not little bluestem that is/are the domianat tallgrass species. This conclusion is based on this authors long-observed tendency of SCS/NRCS range site descriptions to incorrectly extend little bluestem, as the least mesic of the Four Horsemen of thePrairies, as a dominant decreaser far too far westward into the drier portions of the semiarid plains where silver and/or cane bluestems are the ecological equivalent of little bluestem.

This conclusion based on personal observation and experience was inconsistent with conclusions and descriptions in the classic literature. The most specific and crediable example of this was likely that of Allred (in Weaver and Albertson, 1956, ps. 270-272) who in describing Texas grasslands interpreted sideoats grama and silver beardgrass (silver bluestem) as "climax dominants" and grazing-response as decreasers whereas sand dropseed and purplethreeawn sere "dominants that are found throughout but that "are designated as increasers". Allred (in Weaver and Albertson, 1956, p. 272) further concluded: "Cane bluestem is one of the superior bluestems found largely in the southern half of the southern Mixed Prairie. It reseembles silver beardgrass and is often mistaken for it since intergrades of the two species are common". (Incidentially this taxonomic or more precisely, morphological relationship among these bluestems was not recognized by Gould [1975, ps.591-593, 600-601] or Allred, who followed Gould's lead, [in Barkworth et al., 2003, ps. 639-644] when identification was based on length of sessile spikelets.)

Perhaps the most substantiative general interpretation of the successional rank (or status) of silver bluestem on the High Plains was that of Clements (1920, ps. 132, 133, 134). Viewed from Clements' monoclimax model of vegetation bluestem-dominated grasslands were subclimax praire (the Andropogon associes) which in contemporary usage is the tallgrass prairie, that is in or part of the regional Stipa-Bouteloua Formation. This formation, a regional or zonal (climatic) climax, included climax True Prairie and climax Mixed Prairie as well as the subclimax prairie (Clements, 1920, ps. 114, 118-124, 131-134). In the Andropogon associes (association was the Clementsian term reserved to denote the climax unit) Clements (1920, p. 132) recognized a silver bluestem consociation along with consociations for big bluestem, little bluestem, Indiangrass, switchgrass, sideoats grama, and Canada wildrye. Furthermore Clements (1920,p. 133) regarded silver bluestem as intermediate between big bluestem and little bluestem in its water requ;irements. Clearly in this context Clements regarded silver bluestem as of the same or equivalent successional rank as the more commonly regarded tallgrass and midgrass speciesohtkon successional.

Descriptions of rangeland cover types by the Society for Range Management (Shiflet, 1994) that partially described the more xeric forms of mixed prairie included SRM 714 (Grama-Bluestem), SRM 709 (Bluestem-Grama), and SRM 706 (Blue Grama-Sideoats Grama). Each of these three cover type descriptions (by three different authors) listed little bluestem as either a dominant (SRM 714 and SRM 709) or associate (SRM 706) and with big and/or sand bluestem and Indiangrass as associate species (SRM 714 and SRM 709). Silver bluestem was included only in SRM 709 and as a member of "lower seral stages". Both SRM 714 and SRM 709 cover types were described as having physiogonomies of tall and mid-grass aspects. Omission of or relegation of silver bluestem to less than climax decreaser status in SRM descriptions (Shiflet, 1994, ps. 88, 89-90, 93) was inconsistent with the earlier interpretation of successional status of silver bluestem in the High Plains by Allred (in Weaver and Clements, 1956, 270-272). Rangeland cover descriptions were, however, consistent with Nofal et al. (2004) who described silver bluestem as a "a mid-seral, mid-grass". The layman's classic Pasture & Range Plants (Phillips Petroleum Company, 1963; Fort Hays StateUniversity, 2006) specified that in areas of lower precipitation silver bluestem "is often grazed out". This suggested that silver bluestem is more sensitive to abusive grazing and hence of higher successional status in drier range habitats.

Role of and seral or climax rank of purple threeawn in mixed prairie also remains an open question. Perhaps even more so than silver bluestem. Clements (1920, p. 142) included Aristida purpurea as part of the buffalograss-blue grama community in the shortgrass range country of Texas and as part of the blue grama-black grama (Bouteloua eriopoda) vegetation westward into New Mexico and Arizona. Some of the latter included semidesert grasslands, Clements' Desert Plains, in which A. purpurea "in its several forms" was the first named climax dominant of the Aristida-Bouteloua Association complete with an A. purpurea consociation (Clements, 1920, ps.144-146). Clements (1920, p.115, 119) also regarded A. purpurea as a dominant with little bluestem (though, as indicated two paragraphs above, both were interpreted as subclimax) in the Stipa-Bouteloua Formation. Clements (1920, ps. 95, 140) recognized however that Aristida species did invade overgrazed grassland and abandoned cropland. The confused or ambiguous successional ranking of purple threeawn was explained above when that species was introduced.

It is "all well and good" (at least it is acceptable) to generalize sideoats grama and silver bluestem as increasers and members of the purple threeawn (Aristida purpurea) complex as invaders for lay audiences and beginning students as, for example, simplified rules for the Texas Future Farmers of America Range Contest. For more precise purposes in both professional Range Management and research in Range Science species designations as to grazing response (eg. decreaer, increaser, invader), dominance, and influences on the plant community or range ecosystem must be more specific (as in range site-specific). Whereas some range species are always decreasers most species vary as to their responses to disturbance and general succcessional status from range site to range site and from one range region to the next. This is clearly the case with species on mixed prairie. Little bluestem is generally a decreaser, but silver bluestem and sideoats grama are decreaser, increaser, or invader depending on range site or even range microsite (microhabitat). Taxa in the purple threeawn complex are clearly invaders on tallgrass prairie, but they are increasers or even decreasers on some range sites in mixed and shortgrass prairies (and frequently or even typically decreasers on some range habitats in the southwestern deserts).

On the more xeric mixed prairie ranges featured in this section the current author regarded silver bluestem rather than or in addition to little bluestem as the potential natural climax tallgrass dominant of these grasslands in the southern Staked Plains. Other major and, on certain habitats, decreaser grasses included sideoats grama, the dominant midgrass species, blue grama, the dominant shortgrass species, sand dropseed, hairy grama, alkali sacaton, purple (and, perhaps, red) threeawn, buffalograss, and plains bristlegrass.Minor grasses included little bluestem, galleta, vine mesquite, Canada wildrye, and black grama. Major forbs were broom snakeweed (if this is regarded as a subshrub), annual broomweed, western ragwed, mare's-tail or horseweed, Engelmann aster, and kochia. Major shrubs were honey mesquite, sand sagebrush, plains pricklypear, skunkbush sumac, walking stick cholla, southwestern rabbitbrush, and broom snakeweed (if this semiwoody composite was interpreted as a shrub). Along draws and streams (ephemeral and permanent) there was an arboreal element comprised of netleaf hackberry (Celtis reticulata).

252. Mixed Prairie range of the Llano Estacado- Three views of climax mixed prairie comprised of a diversity of mid- and shortgrass species including silver bluestem, "tad bit" of little bluestem, purple threeawn, sideoats grama, blue grama, hairy grama, "smidgen" of black grama, sand dropseed, vine mesquite, alkali sacaton, buffalograss, , western wheatgrass, galleta, plains bristlegrass, Canada wildrye, some curly mesquite, horseweed or mare's-tail, annual broomweed, broom snakeweed, western ragweed, soapweed yucca, kochia, Engelmann aster, plains pricklypear, walkingstick cholla, honey mesquite, skunkbush sumac, sand sagebrush, southwestern rabbitbrush, and netleaf hackberry. All-in-all, amazing species diversity.

Typical physiogonomy of vegetation and topography of land. Rangeland that was basically unaltered since days when the Commanche and Kiowa ruled these Staked Plains. Range condition class varied (almost as much as local range plant communities) from high Fair to low Excellent.

Range vegetation shown in the first of these three photographs showed the phytodiversity of this climax or near-climax plant community including mesquite and netleaf hackberry. Range vegetation in the foreground was a mixture of silver bluestem (left) and various gramas including blue, hairy, and sideoats (center and right; generally the dominant species based on cover and biomass) along with purple threeawn. Forbs were largely absent, but included Fendler's aster and Riddell's groundsel (Senecio riddellii), both of which were visible in foreground vegetation. Soapweed yucca, interpreted by some rangemen as a forb and by others as a shrub, was present as widely scattered individuals.

The second photograph featured a local relict stand dominated by silver bluestem (with some little bluestem) and a diverse mix of mid- and shortgrasses, especially the grama species named above and sand dropseed. Conspicuous in this second (and also the third photograph) were the dead, slender shoots of the annual composite, horseweed or mare's-tail, which is typically a first year-colonizer (invader) of drastically disturbed habitats like abandoned fields (usually the first two to three years after cessation of farming), sacrifice sites on range, and cut-over forests. Presence of horseweed on the relict rangeland site in Excellent range condition class seemed remarkable. The commonness of horseweed in climax (and virgin condition; undisturbed) mixed prairie rangeland may have reflected semiaridity and xericness of this range environment. It was also notworthy that honey mesquite was present at small amounts of cover as was soapweed yucca. Netleaf hackberry grew only in moist draws which ran water ephemerally.

The range plant community presented in the third of these three slides was dominated by silver bluestem which is probably a cecreaser and the natural dominant on this range site in this more xeric portion of the semiarid zone. Sand dropseed was the major associate species to silver bluestem in this third photo-plot.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Autumnal aspect; various phenological stages but mostly early dormancy and secondly flowering and fruit-ripe. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss) and K-62 (Bluestem-Grama Prairie). Several Society for Range Management (Shiflet, 1994) rangeland cover types, but especially SRM 709 (Bluestem-Grama), SRM 714 (Grama-Bluestem), and, locally, partches of SRM 722 (Sand Sagebrush-Mixed Prairie). Mixed "Short-Grass" Series, 142.13, of Plains Grassland biotic community (Brown et al.1998, p. 40). Mixed Land range site. High Plains- Llano Estacado Ecoregion 25i (Griffith et al., 2004).

253. Straightness of the Staked Plains- The Southern High Plains portion of the Great Plains physiographic province has one of the "most nearly level" land surfaces on Earth. This and the "starkness" of the Llano Estacado, the original Spanish name for the Southern High Plains and from which the English Staked Plains was derived, was presented in this landscape-scale view of mixed prairie range.

Walking stick cholla served as a "living stake" while broom snakeweed, a shrub or subshrub, added a tint of yellow-green to a mixed prairie dominated locally by different mixes of various species including silver bluestem, traces of little bluestem, purple threeawn, sideoats grama, blue grama, hairy grama and even small cover of black grama, sand dropseed, western wheatgrass, galleta, plains bristlegrass, vine mesquite, alkali sacaton, buffalograss, curly mesquite. The tall, rank horseweed or mare's-tail, was conspicuous. Less obvious forbs and shrubs included annual broomweed, western ragweed, soapweed yucca, kochia, and plains pricklypear.

Details (close-in views) of this vegetation were presented in the next set of two slides.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Autumnal aspect; various phenological stages but mostly early dormancy and secondly flowering and fruit-ripe. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss) and K-62 (Bluestem-Grama Prairie). Several Society for Range Management (Shiflet, 1994) rangeland cover types, but especially SRM 709 (Bluestem-Grama), SRM 714 (Grama-Bluestem), and, locally, partches of SRM 722 (Sand Sagebrush-Mixed Prairie). Mixed "Short-Grass" Series, 142.13, of Plains Grassland biotic community (Brown et al.1998, p. 40). Mixed Land range site. High Plains- Llano Estacado Ecoregion 25i (Griffith et al., 2004).

254. Vegetational study of the Staked Plains range- Successively closer-in views of the range plant community introduced in the preceding slide. At local, micro-site scale this grassland (mixed prairie) vegetation was composed as (consisted of) various distinct plant communities (ie. plant communities within the larger or overall plant community). Some of these local range plant communities were dominated by silver bluestem while others were made up almost exclusively of gramagrasses (sideoats, blue, hairy gramas) or, alternatively, existed as either stands of purple threeawn or purple threeawn and gramas. Still yet other "micro-communities" (for lack of a more precise term) existed as slightly more species-rich vegetation with broom snakeweed as a shrub or subshrub that sometimes appeared as the aspect dominant.

The second of these two slides presented an example of the latter range plant community in which broom snakeweed was intermixed with a stand of mixed prairie dominated by silver bluestem.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Autumnal aspect; various phenological stages but mostly early dormancy and secondly flowering and fruit-ripe. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss) and K-62 (Bluestem-Grama Prairie). Several Society for Range Management (Shiflet, 1994) rangeland cover types, but especially SRM 709 (Bluestem-Grama), SRM 714 (Grama-Bluestem), and, locally, partches of SRM 722 (Sand Sagebrush-Mixed Prairie). Mixed "Short-Grass" Series, 142.13, of Plains Grassland biotic community (Brown et al.1998, p. 40). Mixed Land range site. High Plains- Llano Estacado Ecoregion 25i (Griffith et al., 2004).

255. Another photographic study of Staked Plains vegetation- The cespitose (bunchgrass) growth form of mid- and shortgrass species produced the open sward physiogonomy of mixed prairie on another part of the same range featured in the two preceding photographs and caption sets. Here silver bluestem along with sideoats, blue, and hairy gramas dominated a clay soil on land that sloped down from a slight rise to a swale. Purple threeawn, like the robust specimen featured in the foreground, occurred sporatically at a relative degree or level that was probably climax for this this range type and range site. Honey mesquite and soapweed yucca were obviously present, but at cover best described as "micro-traces".

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Autumnal aspect; various phenological stages but mostly early dormancy and secondly flowering and fruit-ripe. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss) and K-62 (Bluestem-Grama Prairie). Several Society for Range Management (Shiflet, 1994) rangeland cover types, but especially SRM 709 (Bluestem-Grama), SRM 714 (Grama-Bluestem), and, locally, partches of SRM 722 (Sand Sagebrush-Mixed Prairie). Mixed "Short-Grass" Series, 142.13, of Plains Grassland biotic community (Brown et al.1998, p. 40). Mixed Land range site. High Plains- Llano Estacado Ecoregion 25i (Griffith et al., 2004).

256. A widespread and prickly character- A specimen of plains pricklypear (Opuntia polycantha) growing in the sward presented in preceding photographs of mixed (mostly mid- and shortgrass species) prairie grassland on the Staked Plains. This cactus grows throughout almost the entire latitudinal extent of the Great Plains from the southern most part of the Llano Estacado to the Canadian Prairie Provinces.

Plains pricklypear is of such short stature that all but the shortest grass species (eg. buffalograss) overtop it. As such almost any fire regard less of intensity, rate of spread, etc. will kill high proportions of this cactus.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October.

257. For good measure- Another pair of photographs presented a more mesic habitat in a draw on the Staked Plains (Southern High Plains) on the same range described in the immediately preceding three sets of photographs and their captions. This local range plant community was a "nearly solid stand" of western wheatgrass that could be interpreted as either a population or, alternatively, a Clementsian consociation but with sand sagebrush as a woody component so that this was savannah vegetation.

This western wheatgrass-sand sagebrush savannah had developed on a relatively low north slope above a draw with an ephemeral stream supporting more mesic range vegetation dominated by netleaf hackberry, plains bristlegrass, western wheatgrass, Canada wildrye, and various forbs. This latter range plant community was described below. This savanna was an ecotone among the general plant communities of the more mesic gentle stream channel and draw and the varied range vegetation of the Mixed Land range site described above.

Western wheatgrass is a cool season festicuoid grass that, on this range environment typically completes its annual growth by June or, at latest, early July. Thus this species on this north slope habitat had been dormant for at least three months at time of photograph. Sand sagebrush was nearing fruit-ripe phenological stage.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Autumnal aspect. Phenological stage of western wheatgrass was dormancy while sagebrush approached fruit-ripe. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss) and K-62 (Bluestem-Grama Prairie). Several Society for Range Management (Shiflet, 1994) rangeland cover types, but especially SRM 709 (Bluestem-Grama), SRM 714 (Grama-Bluestem), and, locally, partches of SRM 722 (Sand Sagebrush-Mixed Prairie) which was the local range vegetation featured here. Mixed "Short-Grass" Series, 142.13, of Plains Grassland biotic community (Brown et al.1998, p. 40). Mixed Land range site. High Plains- Llano Estacado Ecoregion 25i (Griffith et al., 2004).

258. A shrub struts its stuff- Sand sagebrush in the western wheatgrass stand (consociation) presented in the two preceding photogrphs. Details of this plant were shown immediately below.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October.

259. Leader of sand sagebrush (Artemisia filifolia)- General (overall) view of major branches of sand sagebrush on a north slope in mixed prairie (within a stand of western wheatgrass) of Texas Llano Estacado (Staked Plains). Leader in woody plants has been defined variously though usually something as to the effect as "the terminal shoot of the main stem" (Munns, 1950) or "the terminal, ie. topmost shoot,charactristic of the growth of certain plants or trees" (Helms, 1998). More generally leader is used by rangemen in reference to woody, especially, major shoots (often including branches) in shrubs and trees.

The vertical shoots of sand sagebrush as shown here emphasized the general morphology and arrangement of organs.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October.

260. A study of sand sagebrush- Details of a major shoot (leader) in sand sagebrush.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October.

261. Some variation (however slight) in Staked Plains physiography- Climax range vegetation in a draw that was the general channel of an ephemeral stream in mixed prairie in the Staked Plains. The much more mesic habitat of this lowland in comparison to the surrounding uplands resulted in this unique strip of range vegetation that was more typical of subhumid climate. This range plant community could be viewed as postclimax in the Clementsian monoclimax model or, alternatively, as a more mesic climax vegetation if viewed from standpoint of Tansian polyclimax theory.

The small trees were netleaf hackberry. Major (dominant) grasses were plains bristlegrass, western wheatgrass, and Canada wildrye. Sideoats grama was the most widely occurring associate grass species. Major forbs included horseweed or mare's-tail, kochia, and Fendler's aster.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Autumnal aspect. This range vegetation was a more mesic range plant community within Staked Plains mixed prairie that developed as a narrow strip (as postclimax) and which was not mapped in major and general treatments like those of Kuchler (1964, 1966). Instead this was a variant of an overall larger unit of natural vegetation with the following designations. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss) and K-62 (Bluestem-Grama Prairie). Several Society for Range Management (Shiflet, 1994) rangeland cover types, but especially SRM 709 (Bluestem-Grama), SRM 714 (Grama-Bluestem), and, locally, partches of SRM 722 (Sand Sagebrush-Mixed Prairie) which was the local range vegetation featured here. Mixed "Short-Grass" Series, 142.13, of Plains Grassland biotic community (Brown et al.1998, p. 40). High Plains- Llano Estacado Ecoregion 25i (Griffith et al., 2004).

262. Another climax dominant of Staked Plains mixed prairie- Plains bristlegrass (Setaria leucopila) on Llanon Estacado mixed prairie. This specimen and those that followed in this section were growing in the draw presented in the immediately preceding photograph and on a slight north slope above the channel of the ephemeral stream in that draw.

Pains bristlegrass comprises a group of morphologically and, presumedly, genetically and taxonomically similar taxa.that have been interpreted variously. Gould (1975, ps. 555-559) explained how S. leucopila, S. macrostachya, S. texana, and S. scheelei were a taxonomic complex with hybridization among them likely. Hitchcock and Chase (1950, ps.721-723, 952-953) applied the species, S. macrostachya, so as to include plants previously designated as S. texana and S. leucopila,an arrangement that they named and described as plains bristlegrass. Gould (1975, ps. 557, 559) explained this noting that S. leucopila "is a highly variable species" He retained S. macrostachya as well as S. texana and S. scheelei (these latter three species without common names). Barkworth et al. (2003, ps. 542, 546-549) retained and described all four of these species using the common names Texas bristlegrass, plains bristlegrass, streambed bristlegrass, and southwestern bristlegrass (S. texana, S. macrostachya, S. leucopila, S. scheelei, respectively). Note the departure from Gould (1975) and the return to the treatment of Hitchcock and Chase (1950) when Barkworth et al. (2003) applied plains bristlegrass to S. macrostachya while using streambed bristlegrass for S. leucopila. The latter common name certainly descaribed the habitat on which specimens presented herein were growing. Incidentially, is it not amazing that in instances like this common names with their lack of (at least, very limited) scientific acceptance have often proved more useful and stable than the scientifiically ordained nomenclature?

Regardless of taxonomy and nomenclature plains bristlegrass is often a dominant, decreaser midgrass throughout much of the mixed prairie and on adjacent range types including transition grasslands that are ecotonal between mixed and shortgrass prairie and semidesert grasslands. This midgrass is both productive and palatable to grazers like cattle, buffalo, elk, and horses.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Hard dought to near grain-ripe stages of phenology.

263. Shoot details of a mixed prairie decreaser- General and distant view of upper portions of shoots of plains bristlegrass in first slide followed in second slide with presentation of panicles and upper internodes (including flag leaf) of two shoots of this species.

Muleshoe National Wildlife Refuge, Bailey County, Texas. October. Hard dought stage of phenology.

264. Spiked panicles on the Staked Plains- Spikelike, contracted panicle of plains bristlegrass, including the flag leaf. The panicle of Setaria species is regarded as contracted (much like those of common grain sorghum (Sorghum bicolor= S. vulgare) though considerable less so than in other panicles such as timothy (Phleum pratense). The branches of the Setaria panicle are appressed against the central stalk of this inflorescence thereby creating this contracted panicle.

Muleshoe National Wildlife Refuge, Bailey Couy, Texas. October. Hard dought stage of phenology.

265. Dueces high- Detailed views of paired spikelets on contracted panicles of plains birstlegrass. In the Paniceae (panicgrass tribe) many members have paired spikelets with these spikelets in turn frequently having paired (two) florets, the upper of which is perfect while the lower floret is reduced (or staminate or neuter). Spikelets in Setaria species are subtened by one to several bristles with disarticulation of spikelets above these bristles (Gould, 1975, p. 21, 24, 542). Spikelets of plains bristlegrass typically have a single birstle. This was shown in these two photographs. This morphological feature, and especially for this taxonomic complex, was also presented to good advantage in Barkworth et al. (2003, p. 549).

Muleshoe National Wildlife Refuge, Bailey Couy, Texas. October. Hard dought stage of phenology.

269.  Indian ricegrass- State Grass of Nevada and Utah. This cespitose grass yields palatable forage that like such shortgrass species as buffalograss, curly mesquite, and blue grama cures well “on the vine”. It is thus especially valuable as winter feed. The nutritious seeds were gathered and pounded into flour by squaws of the various tribes living in the western plains and Intermountain regions. A short and practical reference for this outstanding species is the Natural Resources Conservation Service Plant Guide (Ogle, 2006).

Otero County, Colorado, July.

270. Grain for squaw bread- Spikelets of Indian ricegrass in soft-dough stage. Show here on soil surface in the Central Great Plains was a panicle full of spikelets (florets) featuring the membraneous lemmas surrounding the caryopses of this somewhat rice-resembling member of the Stipeae (needlegrass tribe). The pronounced "hulls" around the small caryopses were thrashed by Indian women to free grain in order that they could make a "bread" (of sorts) from the grass that the white race named commeratively Indian ricegrass (Forest Service, 1940, G88). Awns are typically shed from the lemma long before the grain ripens.

Niobrara County, Wyoming. Late June.

271. Sand bluestem-little bluestem-sand sagebrush- A sand dune cover type. Clements and Weaver (1938) regarded such communities as postclimax, a tallgrass variant type in the mixed prairie region. This cover type is shown in the grassland section because it is a grassland type and is not a sand sagebrush-sand bluestem savanna. This type occurs exclusively on deep sand sites and is interspersed among blue grama-buffalograss, western wheatgrass, and other forms of mixed prairie and shortgrass plains grasslands. 

Chaves County, New Mexico.  June. FRES No. 39 (Prairie Ecosystem). K-63 (Sand Sagebrush-Bluestem Prairie). SRM 720 (Sand Bluestem-Little Bluestem, Dunes). Mescalero Ridge; High Plains- Shinnery Sands Ecoregion. 25j (Omernik and Griffith, 2006)

272. Sand sagebrush (Artemesia filifolia)- This is the major sagebrush species in the mixed prairie grasslands of the Southern Great Plains, both the Rolling Red Prairie (= Rolling Redlands, Redbeds) and High Plains (the Staked Plains or the Llano Estacado). In somewhat greater--though still naturally occurring-- densties or cover sand sagebrush forms a sagebrush mixed prairie savanna or sand sagebrush steppe (SRM 722). On overgrazed ranges and abandoned farmland (ie. "go-back land") sand sagebrush has become a major brush species on par with big sagebrush in the Intermountain West. At densities similar to those of pre-Columbian mixed prairie and sagebrush savanna (the best scientific estimates or "educated guesses") sand sagebrush is a highly desirable component of these ecosystems. It is not only a natural member of the biotic community filling an ecological niche, but it is valuable from such practical standpoints as providing some browse and substantial cover for big game species, furnishing emergency feed sources for livestock during prolongued periods of snow cover, and holding snow (ie. future soil water) that might otherwise blow off the land.

Crowley County, Colorado. July.

278. Standing tall and very thick- Shoots of rhizomatous western whestgrass at peak standing crop. This is a still-yet closer-in-view of the stand shown in the preceding slide. A small (but very sexually repoductive) cheatgrass (Bromus tectorum) plant held its own to clomplete its life cycle in the foreground. This is a good example of sexual vresus asexual reproduction in an annual versus a perennial grass, and of an annual introduced (from Eurasia) invader versus a perennial native decreaeer. Western wheatgrass "hedged its bets" by using both asexual (numerous shoots, modules or ramets, from rhizomes) and sexual (grain production in its many florets as were shown below). Range Management students should familarize themselves with the concept of adaptative "plant strategies" developed by Grime (1979).

Oldham County, Texas. June. Peak standing crop; hard dough stage.

285. Showy milkweed (Asclepias speciosa)- Showy milkweed is one of the more common representatives of Asclepias found on the mixed prairie of the Northern Great Plains. There are at least 16 species of milkweed in North America that have been documented to cause livestock poisoning. Students are referred to the classic text of Kingsbury (1964) and the recent encyclopedic reference by Burrows and Tyrl (2001, ps.125-135 passim). The inflorescences missing from shoots in the lower left foreground were apparently grazed by mule deer based on tracks in the mud adjacent to the plant.

Cardston Municipal District, Alberta. July.

Shown below were three photographs of former fields (row crops and small grains) on highly erodible land that had been successfully reseeded to mixtures of native grasses. These three examples were on the Great Plains physiographic province. The first two slides were from the High Plains (part of the central Great Plains) and the third slide was from the Colorado Piedmont. Both of these are sections or sub-provinces of the Great Plains.

**Note: students in Range Management and Forestry should familarize themselves with the concept of physiographic provinces and study the literature of the provinces in which the ranges and forests with which they work occur. The classic or “bible” for physiography of the “lower 48 states” remains Fenneman (1931, 1938). A more recent, but less detailed, treatment for North America north of Mexico is Hunt (1974). An excellent treatment of the Great Plains specifically is Trimble (1990).

Reseeding range (and replanting forests) is a form of, and a practice within, the category of conservation known as restoration. Conservation is scientific management of natural resources by shifting the rate of resource use to the future. It is a general concept and differs in application and outcome of use between renewable and nonrenewable natural resources. Restoration is that stage of conservation in which there is nonuse combined with some intensity of inputs added back to the natural resource(s) for purposes of replenishing or rebuilding the resoure(s) so that it can again sustain use. Restoration is the lowest rate of resource use in the array of conservation, the lowest stage in the range in rates or levels of resource use. Depletion or exhaustion is the final level or last rate of resource use because the natural resource is either used up, if nonrenewable resources, or exterminated (driven extinct) if a renewable resource such as a species of organism. Exhaustion is nonuse as is restoration, but exhastion is nonuse because the resource formerly received the greatest total use relative to the rates that could sustain use. Using natural resources at rates higher or greater than that (those) which can sustain use (ie. exceeding sustained yield) is the stage known as exploitation. Nonrenewable resources cannot sustain use. That is why they are nonrenewable. Depletion, the result of exploitation, does not have to be total physical or biological elimination (extinction of species most certainly is of course), but it may be economic depletion (ie. the resource becomes so scarce that it cost more to harvest or extract it than it is worth in the prevailing market).

Restoration is that level of scientific management or conservation (= wise use of resources to shift use farther into the future) that attempts to correct the abuses of exploitation which ended in the state of depletion. The goal of restoration is to “bring back”, to replenish, the depleted natural resource(s) so as to be able to use them again at some point in the future. They should then be used at rates that can sustain use (at rates of use consistent with sustained yield). This is the stage in the array of natural resource use known as conservation.

Restoration in this context and strict definition should not be confused with the specific meaning of restoration as that level of reclamation of drastically altered (= drastically disturbed, radically modified, devastated, derelict) lands or ecosystems in which everything is completely returned to the pre-disturbance (prior to the severe perturbation) state. Restoration in that context refers specifically to lands (or waters) disturbed by human actions like mines, quarries, oil fields, abandoned roads, bombing ranges, chanalized rivers, land fills, chemical dumps, etc. The general idea of “land repair” or replenishing of natural resources is consistent with both of these specific uses of restoration.

Restoration is reinvestment in natural resources just as exhaustion was disinvestment in resources (ie. we ate the “seed wheat” and now we must buy more seed to be able to plant wheat if we are to have wheat to eat, and sow, in the future). Examples of natural resource restoration include closed seasons (no open hunting or fishing season) for rare and endangered species, preservation (rates of resource use less than those of conservation) of relict vegetation, and park management for irreplaceable or priceless natural wonders like unique scenery. 

Restoration management or inputs in Range Management and Forestry include reseeding grasses and forbs, replanting woody plants, noxious plant control (reduction in cover, density, etc. of weeds and brush which are ecological invaders of the climax or desired plant community), soil and water conservation structures, fertilization, etc. These are known generally as improvement practices. Range improvement generally and usually means restoration of ranges depleted by overgrazing, under- or overburning, farming, commercial activities, and so forth. Improvement practices such as those just listed aid or increase the rate of range recovery by facilitating the processes of secondary succession. Man gives a boost to Mother Nature to help make amends for his past abuse of natural resources (such as mismanagement of range or forest). Improvement practices differ from developments or development practices such as road and trail construction, water development, fencing, etc. The latter are not restoration practices, but rather management and physical things that facilitate the overall effective use and improve the efficiency— especially the economic efficiency —of use of the resources (including human, financial, and knowledge resources as well as natural resources).

Range reseeding is one of the major categories of range improvement practices (restoration management). The next three slides were chosen as examples of range reseeding that were done under the United States Department of Agriculture Conservation Reserve Program. The Conservation Reserve Program (CRP) was passed in 1985 in response to the fencerow-to-fencerow grain and row crop farming during a relatively brief period during the 1970s (Dr. Earl Butz was Secretary of Agriculture in the Nixon Administration) when the Soviet Union was buying feedstuffs from the USA to build up its livestock and poultry feeding industries. It appeared that the USSR would be buying feed grains and oil seeds from the United States for the proverbial “foreseeable future”. US farmers took a page from the past (or actually failed to read past history correctly) and plowed out fragile grasslands that had been marginal for field crop production under all but the economies of World Wars I and II. The almost immediate result over much of the Great Plains was dust storms that at local community levels were almost on par with those of the 1930s (thought not nearly as widespread as during the infamous Dust Bowl years). There were similar problems with water-caused soil erosion over much of the Midwest. There was concurrent draining of wetlands that were also marginal (sub-marginal actually) for cropland other than in the seemingly good times or happy days of unimaginable market demand for many field crop commodities such as wheat, oil seeds, and feed grains (most notably corn).

As immediate as the farmers fencerow-to-fencerow response was the “hue and cry” from a broad spectrum of concerned citizens that spanned the political spectrum of both major US political parties and from conservatives to welfare liberals. Only some of the most diehard free market libertarians (and those who stood to gain from grain deals) failed to see the classic market failure or negative externality (adverse spillover effects) of this short-term response to what was destined to be a short-lived boom market. Of course many elected and appointed politicians from Farm Belt States elected to keep silent as long as they could (at least up to time of re-election), but there was clearly a groundswell grassroots movement to halt the farming of highly erosion-prone land. All this was to the technically correct war cry of “Dust Bowl”.

Meanwhile the Soviet dictators sensed the weakened power of the US Presidency in the post-Viet Nam, post-Watergate era and the naivette of President Jimmy Carter. Thereupon the USSR invaded neighboring Afghanistan fairly early in the Carter Administration. President Jimmy’s dumbstruck response was an ill-fated and totally ineffective embargo (ban on shipping and/or selling) of American-grown grains to the big bad Russian bear. Like the market-sensitive and ever-optomistic farmers, President Carter failed to correctly interpret history. An executive-ordered embargo (a presidential-invoked prohibition of trade in commodities and/or in departure or entry of commercial ships at US ports) on overseas shipping of commodities that an elected official arbitrarily deems “contraband” will always fail without a naval blockade. The grain US farmers could not sell to the Soviets was sold and shipped by American allies like Canada, Australia, and Argentina. The Carter Administrtion did not have the force of international law (the legal standing), political clot, or the “guts” to blow out of the water Canadian, Australian, and Argentine ships loaded with the kinds of feedstuffs American growers could not sell. The only losers in this fiasco were American farmers, and the reputation of the United States of American as a reliable source or supplier of agricultural products.

The Carter boondoogle over the sales ban on American grain exposed the fencerow-to-fencerow farming and “breaking out” of highly erodable land for what it was: a pact with the Devil in which the US sold its conservation soul and still never had the stones turned into promished bread. This “sad state of affairs” was coupled with that of the now over-extended farmers who had been loaned vast credit for expansion (purchase of more land at inflated prices and expensive farming equipment) based on the inflated value of their farmland (built on the anticipation of increased sales of grain, oil seeds, etc.). By the time Ronald Reagan was elected President the stage was set for the worst farm crisis since the Great Depression. Agri-businesses, banks, and many local retailers in farming communities faced dire financial times. Many went broke. Some farmers committed suicide.

The stage was set for Federal action. Congress acted (in its own due time) with passage of the Food Security Act of 1985. Title XII of this legislation established the Conservation Reserve Program. The CRP would pay farmers to 1) idle or “retire” highly erodable land and 2) seed these acres back to permanent vegetation like native or introduced perennial grasses or, in some cases, trees. The 1985 CRP provision became known as the “sod-buster bill”. Farmers made bids for their land to go into CRP and if their bids were accepted they could enter into a contract with Uncle Sam to keep their erosion-prone land in species that were approved by the USDA (Soil Conservation Service) officials. The maximum  period of this “lease to Uncle Sam” (retirement of highly erodible land from field crop production) was 10 years. “Then what?” remains the over-riding question. The 1990 farm bill expanded the CRP concept to wetlands, the so-called “swamp-buster bill”.

Administration of CRP was largely at the county level and the total amound of land retired under the Conservation Reserve Program was limited to 25% of the cropland in any given county unless it was shown by standards of the program that there would be no adverse economic impacts on the local economy in which case withdrawl for CRP leases was limited to 30% of the cropland in the county. The CRP was reduced somewhat by the 1996 farm bill, and the question of permanence of retirement of highly erodible land remained unresolved.

Conservation Reserve was an older term going back at least to the USDA Soil Bank program initiated in 1956. In all such cases, the stated reason for retiring highly erodible land was soil conservation. Another (and, probably, the major) reason was to reduce crop surpluses and, thereby, crop support payments. Idlying acres was of more immediate concern as a way to reduce costs to US taxpayers, and use tax dollars where congressmen got more votes for their allocations, than as a way to conserve soil and water.  This major—though understated—objective was not totally effective because highly erodible land is by its nature marginal land for field crop production and often, after idlying their marginal fields, producers managed the remaining land more intensively and “made up the difference”.     

The CRP was very effective in getting land back into permanent perennial vegetation (much of this as range or as introduced species that would persist as if they were native). These CRP lands demonstrated two basic lessons: 1) range managers, agronomists, foresters, etc. have developed the technology to revegetate abandoned farmland and 2) land (and water)-owners will respond to economic incentives and adopt conservation practices if “the price is right”. It was certainly to their credit that most farmers supported CRP (afterall they were being paid as much, if not more, than these marginal lands would return as farm fields).

The Conservation Reserve Program was and remains (probably always will remain) controversial. It was just stated that the CRP was, beyond any doubt, an incentive to farmers to idle highly erodible land and replant that land to permanent vegetation that protects it against the ravages of soil erosion.

The CRP (and earlier programs like the Soil Band) was also, however, a clear incentive to farmers to plow out these highly erodible lands in the first place. Farmers could reasonably bet from past history that eventually the US government (and possible some state governments as well) would pay them to put these highly erosion-susceptable acres back into “grass”, land which was marginal for crop production and which should never have plowed under (or drained) to begin with. Meanwhile what about the faithful stewards of the land? What reward, what incentive, was returned to those landowners who cherished their “grass” (native vegetation, or reseeded ranges and permanent agronomic pastures some of which had been established in the first round of conservation plantings after the folly of “sod-busting” had been recognized)? They got nothing, absolutely nothing. Zero. Actually they did get something: competition for their commodities in the market place from the poor stewards who, like Essau, had despised their birthright. Wise land managers had to compete on the open market with those of their fellow producers who had plowed-out their erodible acres and got paid a bonus for such inefficient management and immoral poor stewardship! The farmer who was an unfit steward of his highly erodible land was given a reward for his failed stewardship. Worse yet, this gave him an advantage over the faithful steward who got no financial renumeration and instead had to compete with what by definition was an economically inefficient producer, the very one who did not manage his resources wisely or morally.      

Such goings-on clearly constitute market failure. Where is the social justice, equity, or fairness in such a policy as this? The CRP made the playing field of the market place less level. It sloped the ground of the open market in favor of producers who “broke the rules” and thereby penalized producers who “played by the rules” and who were more economically efficient (as was self-evident by the fact that they did not require a “bail-out” via conservation payments) .

The CRP was a “success story” to those whose main, or only, concern was stopping soil erosion (and providing other conservation benefits like wildlife habitat, clean air, less mining of ground water for irrigation) or who viewed CRP as a bargain because federal renting or leasing of CRP land was less expensive to the taxpayer than continuing to pay price supports. Certainly all “real rangemen” would agree that any reason (or excuse) to put non-arable land— maybe any land for that matter— back into range and negate sod-busting was acceptable to that end. It cannot be denied though that programs like Soil Bank and CRP amounted to subsidies to the economically inefficient producer (and unfaithful steward) while offering unfair competition for the more efficient manager and faithful steward of natural resources.

Finally the big question remains: How long will these landowners who tried to farm sub-marginal land – and were paid a subsidy to do so— keep the land in the CRP. Is there anything to prevent a repeat performance of pay and plow out, pay and plow out, ad infinitum? How can taxpayers be assured that their reinvestment in natural resources— resources for which which they have no property rights — will be a rational investment and not some environmental Enron? What reasonable expectation can those who pay the way for conservation be reasonable assured that programs like the CRP are in final analysis “wise use” of their resources?

In the author’s opinion the Conservation Reserve Program was beneficial overall. Net results of conserving land and related natural resources was worth the cost, but it was marginal. The program had more right than wrong with it, but it is unfair and, ultimately, it will be a flawed and failed approach. There has to be a better way. Maybe some young reader will come up with it.   

The Society for Range Managemeant passed a policy statement and a resolution regarding the Conservation Reserve Program which read in part: “… the Society advocates that productive, sustainable, economically and ecologically sound management systems be developed and applied on all CRP lands. This should be accomplished by keeping highly erodible lands in permanent vegetative cover” (The Trail Boss News, October 2001).

286.   Reseeded mixed prairie- Abandoned cropland reseeded to native tallgrass and midgrass (and, perhaps, even shortgrass) species under the federal Conservation Reserve Program. To conform to conservation compliance within terms of the USDA price support system the owner-operator of this farmland entered into a contract with the United States whereby these highly erodable acres were taken out of row crop and small grains production and restored to a grassland community closely resembling the pre-Columiban or climax mixed prairie grassland. This three-year-old seeding in the beauty of it’s fall foliage included plants of the following native grasses (not in any general order of species composition): little bluestem, sand bluestem, sand lovegrass, Indiangrass, and sideoats grama.

FRES No. 38 (Plains Grasslands Ecosystem), K-60 (Wheatgrass-Bluestem-Needlegrass ) and edge of K-62 (Bluestem-Grama Prairie) were potential natural vegetation mapping units, but this was reseeded was more of K-67 (Nebraska Sandhills Prairie) or a “duke’s mixture” of these adjoining Kuchler units. SRM and range site designations were even less precise (hence, relevant) than larger-scale units of vegetation. This was in the Loess Hills and Dissected Plains area of southwestern Nebraska. Weaver and Alberston (1956, ps. 193-197) provided an apt description of the native grassland vegetation.  Hays County, Nebraska. October (autumnal aspect).

287.  Reseeded mixed prairie- Former cropland on highly erodable acres was reseeded under a Conservation Reserve Program contract to a “real mixture” of native grass species which resulted in grassland restoration to the point of a reconstructed mixed prairie. The dominant species in this mixture as it appeared at time of photograph was sideoats grama. Other grass species found in the reseeded prairie (and presumedly included in the seeding mixture) included plains lovegrass, sand bluestem, and blue grama. Both white and yellow sweet clover were common, but were probably volunteer species. (Melilots [from Melilotus spp.] were common in disturbed areas such as all along highway rights-of-way in this area and they have naturalized over much of the central part of North America, especially the Great Plains.) 

The author recalled vividly driving in a blinding dust storm across this exact location in March 1975, 23 years before he took this photograph. Wind-eroded soil had blown half-way across one lane of the paved highway over lengthy stretches so that motorists were restricted to a single lane. This was of no consequence for travel across this sparsely populated remote area, but the damage to the land and the lives of local people was monumental. Wind-erosion in this southwestern corner of Colorado and adjoining parts of Texas, New Mexico, Oklahoma, and Kansas was one of the most serious problems and major areas of concern that led to passage of the Conservation Reserve Progaram in 1985. Current “black blizzards” and “rolling dusters” such as the one impressed indelibly on the author’s mind were frequently used as examples to prove that such catastrophes and failures of stewardship were immediately pressing serious problems. Such tragedies proved that soil erosion was not just a distant part of history from the “dirty thirties” when Hugh Hammond Bennett evangelized for soil conservation or a Hollywood backdrop for the oppression portrayed in The Grapes of Wrath. It was, however, the right way to end a moralizing picture show when the author took this slide of restored mixed prairie on land that almost a quarter century earlier was blowing away.  

FRES No. 38 (Plains Grassland Ecosystem), K-58 (Grama-Buffalo Grass), SRM would vary locally among 704, 706,and 715, the latter being the regional climax as mapped by Kuchler. Baca County, Colorado. July.

288.  Former irrigated cropland reseeded back to native mixed prairie- The city of Aurora, Colorado was facing dire water shortages as it experienced rapid growth. Aurora did not have water rights sufficient to sustain it’s unsatiable appetite for water. Aurora had to purchase water in the form of water rights in order to survive (at least at the standard of living to which it was accustomed). Aurora had no alternative but to buy the water rights of water-owners, primarily irrigation farmers. For the uninitiated and greenhorns like those from “the East” a short but instructive digression into water law was in order. NOTE: water law is a highly specialized and legally technical body of jurisprudence. In fact it is one of the most technical with many nuances and intricacies. The following thumbnail sketch was offered as an introduction to water law as it pertains to use and ownership of water in agricultural production. This brief description was drawn from the authors nonlegal background and as adopted from general texts especially Barlowe (1986, ps. 344-351).

There are two fundamental legal doctrines of water rights in the United States. The older one which traces back long before English law is the riparian doctrine. Common-law riparian doctrine says in effect that all landowners whose land has or borders on a stream or natural body of water has a property right to a flow of water undiminished in quantity and quality except as may be diminished or changed by upper stream riparian owners solely for domestic purposes and for the watering of livestock. This form of water rights generally holds in all states of the Union except for all or parts of the seventeen western states (often termed the “western range states”). The other basic doctrine of water rights— in total or in some modified form —in all or parts of the seventeen western (the plains, mountains, and Pacific) states is the appropriation (= prior-appropriateion) doctrine, also often known as the Colorado Doctrine after the state that first prescribed it in its state constitution upon admission to the Union.

The prior-appropriateion doctrine asserts that both landowners with riparian water and landowners without riparian water on their property are free to appropriate by legal process water from streams (and acquifiers) for its beneficial use (not restricted to domestic or household and livestock uses). In  net effect, this grants freedom under law to divert water that is not on one’s own land to one’s land for beneficial use. The diverted water then becomes legal property the same as for land, assuming legal procedure was followed in acquiring the property right in water. This separates land ownership from water ownership. The property owner who “got there first” and legally laid claim to water not on his own land became the legal owner of the water that might well be on land later legally owned  (claimed, bought, inherited, etc.) by another. In such case the landowner who adquired the property rights to the land after the water rights were already established does not legally own the water that is on his legally owned land, at least not that part of the water claimed by the waterowner who legally acquired the right to that water by prior beneficial use. Water rights and land rights are completely separate just as in the case where mineral rights on a parcel of land are separate from the rights accruing to land ownership (ie. a land buyer may or may not get water rights or mineral rights). With prior appropriation, water (water rights) can be sold as a real estate commodity the same as land. Obviously in arid and even semiarid regions the water rights become all powerful in determining the value of land (ie. what the land is really worth for cer