Great Basin Desert (inclding marginal contacts

with Colorado and Columbia Plateaus)

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The Great Basin is but one of several parts of the Basin and Range physiographic province (Fenneman, 1931, ps. 348-367; Hunt, 1968, ps. 480-535 passim, specifically 495-499) which also includes various other sections including the Sonoran Desert, Salton Basin, Mexican Highland, and Sacramento (Fenneman, 1931, ps. 326-395). Adjacent and to the north of the Basin and Range province is the Columbia Plateau province (Fennemann, 1931, ps. 225-273; Hunt, 1968, ps. 536-571) whereas adjacent and to the east lies the Colorado Plateau physiographic province (Fenneman, 1931, ps. 274-325; Hunt, 1968, ps. 424-479). The physiographic provinces were used throughout this publication as the most fundamental level or first order of organization for delination of plant (probably plant and animal or, in a synedological context, biotic) communities within the general biome (ie. range cover types within shrublands, grasslands, forests, etc.). This was consistent with the hierarchial unit of mesoscale or landform-- known also as landscape mosaic with landtype units therein-- in the ecoregion system of Bailey (1996, ps. 23-26, 105-119) known as ecosystem geography.

Neither the timeless and traditional physiographic province system of Fenneman (1931, 1938) nor the modern, though traditionally based, ecorgeion (ecosystem geography) hierarchy system (Bailey, 1996, 1998, 2002) is perfectly coincident with the plant formation-biome system perfected by Clements (1916, 1920, 1936), used to map potential natural vegetation by Kuchler (1964, 1966), and as the basis for classification in the latest Clementsian-like biotic community hierarchial designations of Brown et al. (1998). These systems are not completely commenserable and, to the extent that they are incommensurable, represent degrees of scientific revolutions or paradigm shifts (Kuhn, 1962, 1970). Taking all of these systems both individually (to preserve their unique objectives) and then putting them together (incorporating much like ingredients of a hearty stew) does provide a "big picture" view that is remarkable for overall understanding and consistency of easily recognized broad units of range vegetation as, for example, the Great Basin Desert.

The Great Basin portion of the Basin and Range physiographic province (Feneman, 1931, ps.348-367) includes of course numerous mountain ranges, lakes, and streams so as to include both aquatic and terrestrial ecosystems and natural vegetation ranging from desert to alpine with grasslands, woodlands and forests between. The Great Basin Desert is but one--albeit it the largest--part of the Great Basin. Range vegetation of the Great Basin besides desert (ie.forests, pinyon-juniper wodland, grasslands, marshes, alpine) was treated elsewhere in this publication. The vast bulk of the Great Basin is, however, desert shrubland or scrub.

Thus it is that the Great Basin Desert, the North American "cold" desert that is the largest desert in North America and the largest section of the Basin and Range province, has traditionally and still is widely and readily recognized and described even though this large region-sized (at least almost regional in spatial scale) unit of arid shrubland does not coincide completely or perfectly with the Great Basin physiographic provinvce or any other geographic, geologic, ecological, botanical, or biotic unit other than itself. The Great Basin Desert was described-- sometimes by geographic location, climatic (temperature) regime, or plant-animal community if not the Great Basin title-- by Weaver and Clements (1938, ps. 533-535), Jaeger (1957, ps. 142-158), Shelford (1963, ps. 260-281), Bender (1982, ps. 7-102), West (in Barbour and Billings, 1988, ps. 210-222 passim), and Orme (2002, ps. 395-397). A concise but thorough description of the Great Basin Desert was provided by Hulett and Charles in Mares (2004, ps. 252-253).

The Great Basin Desert blends into and runs back and forth among adjoining units of native range vegetation, especially the sagebrush shrub steppe immediately to its north, making exact delination of this immense cold scrubland difficult. Probably the main reason for this difficulty is the omnipresence of sagebrush, especially the various subspecies of big sagebrush (Artemisia tridentata), throughout the Intermountain West including much of the lower elevations of the Rocky Mountains as well as of the sagebrush shrub steppe, pinyon pine-juniper woodland, and even bunchgrass ranges in the Palouse Prairie grassland.

In Classification of North American Biotic Communities Brown et al. (1998, p. 40) distinguished between Great Basin Desertscrub (Great Basin Desert), the biotic community or regional formation, within the Cold Temperate Desertland, the climatic zone or biotic province, versus the Great Basin Shrub-Grassland (sagebrush shrub steppe), the regional formation, within Cold Temperate Grassland, climatic zone or biotic province. The latter vegetation is grassland and was treated under the grassland biome herein. The former is desert (arid scrub) and was covered here under the shrubland biome. Brown et al. (1998, ps. 20-36) described the heirarchial units of their biotic community classification system and they designated various Series units within the regional formation or biotic community of Great Basin Desertscrub (Brown et al., 1998, p. 40). These Series were included below following U.S. Forest Service ecosystems (FRES number and name) and Society for Range Managaement rangeland cover types (SRM number and name). Common names of plant associations designated in Classification of Native Vegetation of Oregon (Kagan, 2004) or, when associations published for Oregon did not match climax vegetation presented, National Vegetation Classifiction for Nevada (Nevada Natural Heritage Program, 2003) were shown following the Series of Brown et al. (1998).

West in Barbour and Billings (1988, p. 212-217; 2000, ps. 261-267) and West in West (1983, ps. 331-374) also distinguished between the sagebrush steppe and Great Basin sagebrush wherein (p. 216) he specifically specified that it was "a mistake" to treat these two distinct general range communities (the former being grassland or grass-shrub savanna and the latter desert shrubland) together or as one range vegetation type. Also, range vegetation of the Great Basin Desert includes plant communities (dominance types) besides or in addition to Great Basin sagebrush (range communities dominated by various Artemisia species) such as the saltbush-greasewood (Atriplex- Sarcobatus) and blackbrush (Coleogyne ramosissima) communities (range cover types).

Classification of native vegetation is on-going and some of the vegetation associations that occur in Oregon as smaller areas were not included in the Oregon classification list (Kagan et al. 2004). Some of these associations of the Great Basin Desert dominate larger areas of land in Nevada and were included in the Nevada vegetation classification (Nevada Natural Heritage Program, 2003). Examples of such associations found in southeastern Oregon were designated below by association names from the Nevada list (Nevada Natural Heritage Program, 2003). Names of associations on the Nevada vegetation list were presented using only scientific names of plants whereas units of vegetation (actually, biotic communities) in Brown et al. (1998) were given only as common names. As such there was unavoidable inconsistency in expressing nomenclature of vegetation.

The general treatment of Great Basin Desert below followed the organization of vegetation maps ( Kuchler, 1964, 1966) and general descriptions of biomes (Shelford, 1963) and ecosystems (West, in West, 1983). These efforts followed from the original and large spatial-scale perspective of Clements (1920, ps.152-160) who interpreted this general desert community as the Basin Sagebrush (Atriplex-Artemisia Association) of the Atriplex-Artemisia Formation of the Sagebrush Climax. Dominant shrubs that formed consociations within the Atriplex-Artemisia Association included various sagebrush (Artemisia) species such as big sagebrush (A. tridentata), low sagebrush (A. arbuscula), silver sagebrush (A. cana), shadscale (Atriplex confertifolia), four-wing saltbush (A. canescens), rubber rabbitbrush (Chrysothamnus nauseosus), viscid or Douglas rabbitbrush (C. viscidiflorus), winterfat (Eurotia lanata), spiny hopsage (Grayia spinosa), thorny horsebrush (Tetradymia spinosa), and broom snakeweed (Gutierrezia sarthrae). This same format and classification of natural vegetation was followed by Brown et al. (1998) who unabashedly adopted the Clementsian paradigm in their classification scheme (Brown et al., 1998, ps. 11-12). Thus, Brown et al., (1998, p.40) had within their Great Basin Desertscrub biotic community the following: Sagebrush Series, Shadscale Series, Blackbrush Series, Rabbitbrush Series, Winterfat Series, Mixed Scrub Series, and Saltbrush Series.

Close correspondence of the more extensive range plant communities of Clements (1920, esp. p. 157) and Brown et al. (1998, p. 40) with those of West (eg. in Barbour and Billings, 1988, ps. 212-217) was remarkable, but curiously West did not recognize Great Basin shrubland communities dominated by winterfat and rabbitbrush while Clements, in context of what became known as his monoclimax theory, (1920, p. 158-159) interpreted black greaswoood (Sarcobatus vermiculatus) as the most saline adapted major shrub that is subclimax to those shrub species that comprised consociations (climaxes dominated by a single species). Although the Society For Range Management (Shiflet, 1994, ps. 40-48) recognized Great Basin rangeland cover types based on dominance by single species of sagebrush, which was perfectly consistent with the consociations listed by Clements (1920, p. 157), Paul Tueller (Shiflet, 1994, ps.53-54) lumped shadscale, black greasewood, and winterfat together under one rangeland cover type, Salt Desert Shrub (414). This resulted in an inconsistency between Society for Range Management types and those of Clements (1920, 152-160), West (in Barbour and Billings, 1988, ps. 216-222 and 2000, ps. 265-271), and Brown et al. (1998, p. 40). Similarly, Clements (1920) did not name or describe plant communities dominated by blackbrush whereas a blackbrush type was recognized by Kuchler (1964, p. 39), West (in West, 1983, ps. 399-411; in Barbour and Billings, 1988, p. 222), the Society for Range Management (Shiflet, 1994, p. 21-22), and Brown et al. (1998, p. 40). The blackbrush range type is more common in the Mojave Desert, southeastern portion of the Great Basin Desert, and the ecotone between these two deserts. This fact was noted by West (Barbour and Billings, 1988; Barbour and Billings, 2000), the Society for Range Management (Shiflet, 1994), and Brown et al. (1998), the latter of whom listed a Blackbrush Series for both the Great Basin and Mojave Desertscrub.
 

After the Clements-Weaver-Sampson-Braun pioneer era of Plant Ecology "second generation" synecologists, especially range ecologists, blended the original Clementsian paradigm with what grew into the polyclimax theory from the views of Tansley (1935) and the climax pattern theory of Whittaker (1953) to describe in greater detail and consistency natural vegetation of North America. Actually the "breaking up" of Clementsian biomes and plant formations into smaller units was evident early on in descriptions and studies of grasslands by Weaver (1954) and Weaver and Albertson (1956) and by Shelford (1963). This trend persisted with the International Biological Program trying--and more-or-less successfully--to "serve two masters" by basing its ecosystem (Tansley, 1935) studies around the biome or biotic community (Clements and Shelford, 1929) framework (Golly, 1993).

This same or very similar approach was applied to what Clements (1920) identified as the Atriplex -Artemisia Association and Formation (see again above). Shelford (1963, ps. 260-281) divided what he designated as the shadscale-kangaroo rat-sagebrush biome into1) the Shadscale-Kangaroo Rat Association consisting of a) Shadscale-Rice Grass-Ord's Kangaroo Rat Faciation, b) Greasewood-Harvest Mouse Faciation, and c) Winterfat-Rice Grass-Kangaroo Mouse Faciation and 2) Sagebrush-Rabbit Association consisting of a) Sagebrush-Jack Rabbit-Wheatgrass Faciation, b) Sagebrush-Pygmy Rabbit- Bitterbrush Faciation, and c) High Altitude Sagebrush-Cottontail-Cream Bush Facition. There were also edaphic-climatic and hydrosere communities within the associations.

Indicative of the trend toward description (and subsequent management) of Great Basin range vegetation into smaller units of hierarchy ranked vegetation was the move by Shelford (1963, ps. 260-281) to to split the single Clementsian Atriplex- Artemisia Association into a separate Atriplex Association and an Artemisia Association. That done, Shelford converted some of the consociations of the Clementsian joint Atriplex-Artemisia Association (Clements, 1920, p. 157) into faciations (Clementsian hierarchy unit of vegetation below or under association) of the now separate Atriplex Association or Artemisia Association.

Shelford (1963. ps. 350-354) interpreted the Palouse Prairie as extending "...into the Great Basin of California and Nevada..." and being "...in the basins of the Columbia and Snake rivers, largely surrounded by the Cascade and various ranges of the Rocky Mountains". In this treatment (Shelford, 1963, p. 35) distinguished the Great Basin Sagebrush (Artemisia) of Kuchler (1964, p. 38) from Sagebrush Steppe (Artemisia-Agropyron) of Kuchler (1964, p. 55) and Wheatgrass-Needlegrass Shrubsteppe (Agropyron-Stipa-Artemisia) of Kuchler (1964, p. 56). Kuchler (1964, p. 40) also recognized Saltbush-Greasewood (Atriplex-Sarcobatus) in the Great Basin. These units were retained in later Kuchler maps of potential natural vegetation and for development of forest and range ecosystems (both uses employed in Garrison et al., 1977). Consistent with this distinction, Garrison et al. (1977) recognized Shrubland Ecosystem 29 (Sagebrush) and Shrubland Ecosystem 30 (Desert Shrub).

In the previously cited classic synopses of Intermountain vegetation by West (in West, 1983, ps. 331-421; in Barbour and Billings, 1988, ps. 212-217 and 2000, ps. 265-271) the potential natural vegetation units of Kuchler (1964, 1966) and as used by Garrison et al.(1977) were retained and adapted for description purposes. West's work also followed and was consistent with that of Shelford (1963) complete with photographs of Ord's kangaroo rat (West, 1983, p. 388). In effect, contemporary nomenclature, description, and discussion of Great Basin Desert vegetation remained consistent with the original treatment by Clements and his loyal band, minus the Greek language-derived units of vegetation and the vegetation-is-an-organism philosophy. (Rangemen have great respect for precident and are notarious traditionalists, the present author included.)

Division of the Great Basin Desert into the two main units of 1) and sagebrush and 2) saltbush-greasewood which were then further subdivided along with separation of sagebrush scrubland (desert) from sagebrush-defined steppe (the greater Palouse Prairie grassland region) became the traditional organization by which range vegetation of the Intermountain Region and the Great Basin Shrubland were treated. That traditional treatment of the Great Basin Desert was followed below.

 
Great Basin Sagebrush
 
Climax range vegetation dominated by one to several species of sagebrush, especially big sagebrush (Artemisia tridentata) is one of two major categories of Great Basin desertscrub. The other major unit of Great Basin potential natural vegetation is saltbush-greasewood. These two broadest, most general units of Great Basin scrub were recognized by Shelford (1963, ps. 260, 269, 277) as associations of the shadscale-sagebrush formation and association of Clements (1920). "Great Basin sagebrush" was the title of a Kuchler (1964, 1966) "vegetation type" or map unit of potential natural vegetation. "Great Basin sagebrush" was used by West (in Barbour and Billings, 1988, p. 216 and 2000, p. 265). Sagebrush-dominated range vegetation was treated as Shrubland Ecosystem 29 (Sagebrush) by USDA Forest Service (Garrison et al. 1977).

 

1. The Great Basin Desert- The largest desert in North America is this "high" or "cold" desert. The almost universal dominant of the Great Basin desert is big sagebrush (Artemisia tridentata), regarded as existing as at least three subspecies. Species of rabbitbrush (Chrysothamnus) are the other major woody composites of the High Desert. Various species of juniper (especially Juniperus occidentalis and, less commonly, J. osteosperma) add an arboreal component. Peaks of the Toiyabe Range, Lander County, Nevada. FRES No. 29 (Sagebrush Shrubland Ecosystem). K- 32 (Great Basin Sagebrush). Composite of several Great Basin cover types (e.g. SRM 401, Basin Big Sagebrush; 408, Other Sagebrush Types; 412, Juniper-Pinyon Woodland). Overall, Mixed Scrub Series of Brown et al. (1998). Juniperus osteosperma/Artemisia tridentata Woodland (Nevada Natural Heritage Program, 2003).
 
2. Big Sagebrush-dominated High Desert- This is an Artemisia consociation with very little herbaceous understory except from scattered Sandberg bluegrass (Poa secunda= P. sandbergii) and, of course, the naturalized Mediterranean annual cheatgrass or downy brome (Bromus tectorum). It is a matter of some debate as to whether stands of big sagebrush (and other Artemisia species) like this are climax (or the pre-Columbian) vegetation or if human disturbances like overgrazing, fire suppression, commerce, and cultivation (or even climatic changes) reduced the herbaceous understory leaving a partly "man-made" desert. Research suggests that range communities under virgin conditions were in a continuum from pure stands of sagebrush or sagebrush and rabbitbrush through the savanna form of sagebrush shrub steppe to essentially shrub-free grasslands like the Palouse Prairie. The "pure"stand of big sagebrush seen here represents the more xeric form of the Great Basin, as well as desertification, human-induced deserts or what Paul Sears described as Deserts on the March. University of Nevada Gund Ranch, Lander County, Nevada.March. FRES No. 29 (Sagebrush Shrubland Ecosystem). K-32 (Great Basin Sagebrush). SRM 401 (Basin Big Sagebrush). Sagebrush Series of Brown et al. (1998). Artemisia tridentata ssp. tridentata/Poa secunda Shrubland (Nevada Natural Heritage Program, 2003).
 

3. Basin big sagebrush in a big basin- Across this wide basin (it would be called a valley if it were not in the Basin and Range physiographic province) Artemisia tridentata ssp. tridentata formed a consociation as a shrubland without an herbaceous understorey, except for the inadvertant planting by white man of cheatgrass. There were also numerous plants of the Eurasian annual crucifers, tumble mustrd (Sisy altissimum) and pinnate tansy mustard (Descuriania pinnata).

This sagebrush range was degraded. It had undergone retrogression so that whatever herbaceous layer(s) had been present in the virgin vegetation were now largely gone having been replaced by naturalized annuals (mostly cheatgrass) Exact successional status of this range vegetation was uncertain without a reference climax plant community. If there had been limited herbaceous understorey in the natural vegetation then development of an herbaceous (and a grazable) layer of annual plants might have limited influence on the existing plant community or range ecosystem. Conversely, if there had been a diverse herbaceous understorey of, say, Indian ricegrass (Oryzopsis hymenoides= Stipa hymenoides), galleta (Hilaria jamesii), needlegrasses (Stipa spp), or Sandberg bluegrass (Poa secunda= P. sandbergii), which were species present on some nearby ranges, this pasture was in a successional state of retrogression and, perhaps, severe degradation.

Judging from the cover and biomass produced by cheatgrass in a typical year with about average amounts of winter-spring precipitation and soil moisture, it seemed highly propable that climax range vegetation on this site would include some native perennial grasses of the regional climax such as those listed above. Students, however, should note carefully that that is NOT the same as concluding that these probable component grass species of the virgin range would--or even could--naturally reinvade and persist on this range in human time scale. They more than likely would or could not do so given probable degree of range depletion and establishment of cheatgrass and annual crucifers. This is likely to be the case when the time scale is measured in decades rather than centuries or millenia (not to mention the four-year span associated with a US presidential term).

The range vegetation seen here is most probably a grazing disclimax (disturbance climax) induced a century ago by overgrazing of the Public Domain when it was open range (a grazing commons that was "open to the public" and "free of charge"). This was accerbated by the wihte man's introduction of Eurasian annuals which, in absence of natural enemies and maybe "empty niches", quickly (and permanently in human time) naturalized and displaced native plants. Different fire regimens, climatic shifts, and such human commercial actions as vehicular transportation were likely contributing factors.

If a natural herbaceous layer of native perennial bunchgrasses was replaced by one of alien annuals there is still herbaceous biomass that functions to provide some protection of soil that is not covered by woody plants. Such herbage adds organic matter which cycles soil nutrients. Herbage from exotic plants can be used as forage by some herbivores. Herbaceous plant material serves as "mulch" or "stubble" to slow velocity of wind and flowing water. This enhances wateshed functions and helps to preserve water quality.

One fact is certain based on practical, every year-experience: if this rangeland burns with its annual grass and forb component providing fine fuels for a fairly "hot" fire, the nonsprouting big sagebrush will be killed--perhaps indefinitely--leaving a cheatgrass range that is poor or, at best, fair wildlife habitat and less effective as a watershed.

To a point range managers can manage for vegetation "that used to be" (eg. the pre-Columbian range plant community) or for vegetation that "might be" at some point in the future (eg. higher range condition class), but in final analysis rangemen must manage the range vegetation that is there now. One can--successfully or unsuccessfully--manage for some kind of vegetation, but one can only manage vegetation that is there at present.

Question #1, Buckeroo Range Management 101 (Sign-reading). This range had, beyond any doubt, been grazed earlier this spring. What irrefutiable evidence was clearly present to substantiate this statement of fact. Answer #1. Cheatgrass beneath and or close to crowns of sagebrush was much greater in height (at least twice as tall) as cheatgrass in interspaces among sagebrush. Animals avoid grazing close to objects that might injure their eyes or muzzles. Grazing animals learn to keep their heads a safe distance from woody plants unless they are browsing these (which they do preferentially and with due selectivity and safety).

Questioin #2, Buckeroo Range Management 101 (Grazing Management). Spring (perhaps late winter) grazing of this range was not only sound management it was the grazing practice of choice. Explain. Answer #2. Point 1.Cheatgrass is an exotic range weed. It can--often does--outcompete the native perennial bunchgrasses. It typically germinates and begins to produce plant tissue that can be grazed before several of the perennial grasses green-up and/or achieve grazable size. Grazing cheatgrass at these early stages benefits most of the native forage species by shifting grazing pressure from natives to the more abundant annual cheatgrass (assuming proper stocking rate). This is a form of forced selective grazing or biological weed control. Point 2. Cheatgrass is a source of nutritious forage when it is still green and growing. As soon as this weedy annual completes its life cycle (produces grains and dies) the feed resource it produced will begin to be lost physically (dries up and blows away; disintegrates, rots or decomposes) and chemically (nutrients and energy content decline with advancing plant maturity and degradation). Use this range feed now or loose it. Rangemen do not let feed go waste unless this plant material is reserved as fuel for prescribed fire, cover on fragile watersheds, part of specialized grazing management, etc. (in which cases the phytomass was not feed). Point 3. After cheatgrass has died and attained a feed value equivalent to that of straw (which is exactly what it is at this phenological stage) livestock should be moved to better range. This benefits the livestock (hence the stockman) and it benefits any native perennials which can now grow and reproduce in what is left of the grass-growing season. Point 4. Utilization of this feed by livestock will reduce plant material that could serve as a source of fuel for wild fire. Even if fire breaks out on this range, grazing will result in reduced intensity of any fire and decrease likelihood of killing most big sagebrush which, should this happen, would leave a man-made monoculture of cheatgrass. Reduction of herbage from annuals maintains dead fuel more like that available from native herbs. Point 5. Protection of big sagebrush from total kill will benefit wildlife that feed on it and/or use it for cover.

You didn't put all that down!. Why not? It was an essay question and you had a whole blank page. Where's that red pen.

 
4. Basin big sagebrush (Artemesia tridentata tridentata)- Apical portion of basin big sagebrush showing chacteristic growth pattern and terminal leaders. Green River flood plain, Dinosaur National Monument, Unita County, Utah. June.
 
5. Rubber rabbitbrush (Chrysothamnus nauseosus)- Chrysothamnus and Artemesia species are the co-dominant composite shrubs of millions of acres of rangeland in the Intermountain Region, the vast domain between the Rocky Mountains and the Sierra Nevada-Cascades Ranges. Sagebrush is usually far and away the dominant, but range species composition varies site-by-site. Much of the Intermountain Region is Great Basin Cold Desert or Mojave Desert, but it also includes the Palouse Prairie which is bunchgrass prairie called by the Russian term steppe and a shrub savanna of Palouse Prairie herbaceous species with scattered shrubs of mostly sagebrush and rabbitbrush but also some of other families like the Chenopodaceae. As with other conditions where there are high proportions of trees and shrubs on grassland and savanna these are woody invasions due to overgrazing, reduced fire regimens, past cultivation, commercial traffic, etc. They are a symptom and part of the cause of retrogression resulting in range deterioration.
 
These are native plants and occupy ecological niches essential for full-functioning of range ecosystems. They are usually not highly nutritions and, in fact, contain anti-nutritional compounds like terpenes which have adverse impacts of animal nutrition (often through reduced reticulo-rumen microbial activity). They are emergency sources of feed in severe winter weather and can be of nutritional value in botanically diverse animal dies. They provide cover for different species of wildlife and help to retain blowing snow on the arid landscape. In short, all rabbitbrush and sagebrush species are beneficial at the right proportions, usually those resembling their proportions in the climax vegetation.
 
As a result of human abuse most populations of rabbitbrush and sagebrush are excessive to the point that they are noxious woody range plants (ie. brush). Brush control, the reduction in numbers and/or cover of woody invaders, is proper management of any species whose populations have become excessive (either ecologically or economically). Brush control is often a vital part of proper range management. All Range Management students must familarize themselves with details of brush management levels including prevention and, rarely, eradication as well as control. In most cases it is too late for prevention thus leaving some level of control as the only real management option. Eradication, the complete removal of all individuals including propagules of the noxious species from the management area such that re-population is not possible (ie. local extinction), is not legitimate management for native species except at restricted locations (eg. barnyards, gardens, lawns). Eradication is a management objective for introduced pests, especially diseases. Valuable woody plants such as browse species are not brush which in a strict sense is a term reserved for noxious trees, shrubs, and woody vines (ie. woody weeds).
 
Cache County, Utah. July.
 
6. Flowering leaders of rubber rabbitbrush- Las Animas County, Colorado. August.


7. Inflorescences and fruit of rubber rabbitbrush- Armstrong County, Texas. September.

 

8. Good composite shot of high desert scrub probably typical of Great Basin climax vegetation- The olive-brown shrubs are antelope bitterbrush (Purshia tridentata), arguably the single most valuable browse plant on the Western Range. Rabbitbrush, winterfat, and several sagebrush species including low sagebrush (Artemisia arbuscula) and black sagebrush (A. nova) as well as ever-present big sagebrush comprise a diverse desert upperstory. The sparse but dominant understory herb is Indian ricegrass. Cheatgrass was essentially absent.

This was an example of the Sagebrush-Pygmy Rabbit-Bitterbrush Faciation of Shelford (1963, ps. 278-280). Note pygmy rabbit (Brachylagus idahoensis) under black sagebrush plant at right margin. What do you mean you can't see him? Of course he's hard to see. He's a pygmy.

A BLM allotment. Mono County, California. February. FRES no. 29 (Sagebrush Ecosystem). Variant of K-32 (Great Basin Sagebrush).This bitterbrush-rabbitbrush-sagebrush Great Basin range type was not described by SRM per se; it is one variant of SRM 210 (Bitterbrush). Variant of Sagebrush Series of Brown et al. (1998).

 
Great Basin Salt Desert Shrubland
 

Salt desert shrub is the accepted designation for that part of the Great Basin Desert that species-wise is defined primarily by the saltbush-greasewood unit of vegetation-- regardless of level in organization hierarchy of vegetation (dominance type, association, consociation, fasciation, alliance, whatever)-- in contrast to the unit of Great Basin sagebrush. Designation of "salt desert shrub" can be traced back to pioneer work in Intermountain Region vegetation as, for example, in Flora of Utah and Nevada (Shantz in Tidestrom, 1925, p. 19).

In the Great Basin the most common of the dominant saltbushes (largest acreage dominated) is shadscale or spiny saltbush (Atriplex confertifolia). Black greasewood (Sarcobatus vermiculatus) is the second (and second-most) defining and dominant species of the salt desert shrubland. Saltbush and greasewood sometimes grow without one or the other species whereas on other range types and range sites the two species grow in various relative proportions ranging from co-dominants to dominant-associate rank, dominant-incidental rank, both associates, or even both incidental species. In latter instances, shadscale and/or greasewood would not be defining species though they might well still be indicator, key, or keystone species. On some range habitats, greasewood or shadscale form consociations of such "purity" as to be single-species stands or more as populations than as plant communities. In such range vegetation shadscale or greasewood is the "whole enchilada".

Of these two overall dominant species of the salt desert shrubland, shadscale has typically been viewed as the more important or diagnostic species across the Great Basin. Mozingo (191987, p. 52) summarily wrote: "Three shrubs are especially characteristic of the Great Basin- sagebrush, rabbitbrush, and shadscale." This observation was consistent with the view of "Great Basin sagebrush" and "saltbush-greasewood" (Kuchler, 1964, 1966) as the two major "vegetation types" of the Great Basin Region. However, Shantz (in Tidestrom, 1925, p. 16-19) had the opposite view and recognized a Greasewood Formation and included the Shadscale Association as part of the Northern Desert Shrub.

Other major--and frequently dominant--shrubs of the Great Basin salt desert shrubland (shadscale-greasewood unit or type) include winterfat (Eurotia lanata= Ceratoides lanata), fourwing saltbush (Atriplex canescens), blackbrush (Coleogyne ramosissima), spiny hopsage (Grayia spinosa), and various species of Mormon tea or jointfir (Ephedra spp.). Winterfat could be interpreted as the third-most important or defining species of Great Basin salt desert shrubland based on acreage dominated and feed value to livestock and wildlife. Blackbrush is also distinctive, especially as related to delineating Great Basin and Mojave Deserts.

The following treatment of the Great Basin salt desert shrubland was organized as to dominant species comprising the salt desert unit of Great Basin Desert. Generally speaking, one of the major shrub species of the Great Basin Desert will be a fairly obvious dominant such that it conveniently defines and indicates a range cover type (eg. shadscale cover type, greasewood cover type, winterfat cover type, blackbrush cover type). In cases of co-dominance as, for instance, shadscale and blackgreasewood then this can be readily accomodated as a two species designation (eg. shadscale-greasweood rangeland cover type) The Society for Range Management (Shiflet, 1994) followed this convention with regard sagebrush species and even subspecies whereas shrub species of the salt desert shrub were "lumped" into a catch-allI or generic rangeland cover type. Dominant species were used as basis for range types in the following discussion.

 
Great Basin Shadscale (including related Mixed Shrub)
 

Shadscale-black greasewood-dominated scrub and sagebrush-dominated shrubland are the two broad range "vegetation types" of Great Basin Desert. These two general types of natural plant communities were seen as plant associations by Shelford (1963, ps. 260-281). Kuchler (1964, 1966) combined or "lumped" together the major two chenopodacious species (and they are bodacious) as a "vegetation type" and mapping unit of potential natural vegetation entitled "Saltbush-greasewood (Atriplex-Sarcobatus)". West (in Barbour and Billings, 1988, p. 217 and 2000, p 267) followed Kuchler's lead and kept the same title noting that the saltbush-greasewood community constitutes what is commonly known as the "salt-desert shrub".

Brown et al. (1998, p. 40) subdivided Great Basin Desertscrub into seven biotic communities including Shadscale Series, Saltbush Series, Winterfat Series, and Sagebrush Series. Tueller (in Shiflet, 1994, p.53-54) authored the Society for Range Management rangeland cover type, Salt Desert Shrub (SRM 414), in which shadscale, black greasewood, winterfat, and several other native shrubs were included under this one umbrella cover type. This was in contrast to treatments of sagebrush in Shiflet (1994) which separated out sagebrush species and even big sagebrush subspecies and used each taxon as basis for a separate cover type. In this chapter the present author followed the convention established by the first, and most subsequent, authors and interpreted each dominant Great Basin shrub species as representing a separate and unique dominance (=cover) type.

Shadscale has generally been interpreted as the regional climax dominant shrub of the salt-desert scrub form of Great Basin Desert. Shadscale apparently forms more associations than does black greasewood (14 versus 10, respectively, listed in The National Vegetation Classification for Nevada [Nevada Natural Heritage Program, 26 September, 2003]). Shadscale-dominated range communities vary widely ranging from shrubland consociations of "pure" shadscale minus even cheatgrass understorey to shadscale-associated shrubs shrubland to more savanna-like shadscale-herbaceous species scrub. Historic or successional status of many or, more likely, most of these shadscale-dominated range communities is uncertain. It is certain that shadscale is a major defining range shrub of the Great Basin Desert and surrounding grazing lands.

Time now for shadscale.

 

9. Shadscale on a sink- This alkaline sink was dominated by shadscale with Douglas or viscid rabbitbrush (Chrysothamnus viscidflorus), conspicuous by brighter green color, as associate species.The third major range plant was Shockley buckwheat (Eriogonum shockleyi) which comprised a second and low shrub layer. Other shrubs present in much smaller proportions included winterfat (Eurotia lanata= Ceratoides lanata), bud sagebrush (Artemisia spinescens), and, least of all, black sagebrush (A. nova). The two major grasses were Indian ricegrass (Oryzopsis hymenoides= Stipa hymenoides) and galleta (Hilaria jamesii). Needle-and-thread (Stipa comata) was present but nowhere as common as on semidesert grasslands in the general vicinity of this salt desert scrubland. Cheatgrass was largely restricted to local areas of severe disturbance or lowered soil surface (eg. eroded entrances of rodent burrows). The main forb was the native biennial or short-lived perennial crucifer, wallflower (Erysium asperum= E. capitatum= E. elatum), followed by the annual crucifer, hairy pepperplant or hispidcress (Lepidium lasiocarpum var. lasiocarpum).

In spite of monotonous outer appearance, there was much local variation in this range vegetation with miscellaneous combinations of plants that grew in close proximity. Some of these local affilitations were presented below. This alkaline sink was a combination of browse and grass range. Most of the browse species (with examples from this range) were shown below.

Example of range vegetation on one pasture of a five-range combination deferred rotation-rest rotation grazing system. On this BLM allotment in four years of five the grazing season (for cattle) runs from 1 April through 31 October and during the fifth year cattle grazing starts 1 May and extends through 30 November.

As shown this range plant community was a shadscale-viscid or Douglas rabbitbrush scrubland. Tueller (1975, p. 6) suspected that this plant community, which developed extensive over much of central Nevada was a grazing disclimax. Shelford (1963, p.273) concluded that viscid rabbitbrush "... is a subclimax species that is widespread in the desert". The climax or potential natural vegetation on this range site would probably be either Atriplex confertifolia/Achnatherum hymenoides Shrubland or Atriplex confertifolia/Pleuraphis jamesii Shrubland (Nevada Natural Heritage Program, 26, September, 2003) which is shadscale-Indian ricegrass or shadscale-galleta shrubland. Shelford (1963, ps. 269-271) described this range vegetation under Shadscale-Rice Grass-Ord's Kangaroo Rat Faciation. (Entrance to burrow of this long-tailed rodent was presented below).

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, estival aspect with species in numerous phenological stages. FRES No. 30 (Desert Shrub Shrubland ecosystem). K-34 (Saltbush-Greasewood). SRM 414 (Salt Desert Shrub). Shadscale Sries 152.14 of Great Basin Desertscrub 152.1 (Brown et al., 1998, p. 40). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13c (Woods et al., 2001).

 

10. Only slightly higher ground but substantially different range- Immediately adjacent to range vegetation of the alkaline sink presented in the two preceding slides there was a conspicuously different range plant community that was shown in these two slides. On this second range site shadscale was still the most common shrub but there was not an obvious dominant species as winterfat, bud sagebrush, viscid rabbitbrush, black sagebrush, basin big sagebrush, and fourwing saltbush (Atriplex canescens) were present with relatively high aerial cover. Neither was viscid rabbitbrush present in proportions of an associate species. Shockley buckwheat had all but disappeared as a member of the lower shrub layer. The three native perennial grasses were still present on this range site, but cheatgrass was much more common. Most conspicuous of all was relatively high cover (and locally high density) of the two Eurasian annual crucifers, pinnate tansy mustard (Descurainia pinnata) and tumble mustard (Sisymbrium altissmium). High populations of these alien weeds contrasted sharply with occurrence of the native wallflower as the main range forb on the alkaline sink. The annual mustards and cheatgrass were the source of brown coloration across this range site. Russian thistle or the classic 'tumbleweed" (Salsola kali= S. pestifer= S. iberica) was the other annual Eurasian species that was locally abundant (mostly on rodent-disturbed areas). Russian thistle is a warm-season chenopod such that it was still small and green at time of photograph (see below).

Mixed shrub-grass range like this is valuable for both browse and forage (grass) species. Examples of browse plants growing on this range were included below.

This range was one of five pastures managed as a combination rest rotation-deferred rotation system grazed by cattle. Grazing season was from 1 April through 31 October four years out of five with the fifth year having a turn-on date of 1 May and take-off date of 30 November.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, early estival aspect. FRES No. 30 (Desert Shrub). K-34 (Saltbush-Greasewood). SRM 414 (Salt Desert Shrub). Mixed Scrub Series 152.16 of Great Basin Desertscrub 152.1 (Brown et al., 1998, p. 40). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13c (Woods et al., 2001).

 

11. Rats-annual weeds!- Soil disturbance at entrance to this Ord's kangaroo rat (Dipodomys ordii) burrow provided a microsite favorable for establishment of two common Eurasian annual plants. Cool-season cheatgrass or downy brome (at "seed-shatter"-dead plant phenological stage) had completed its annual life cycle down in the "throat" of this jumping rodent's house. The warm-season Russian thistle was in early stages of growth on perturbed soil all around burrow opening. In the range site of this alkaline sink annual species could not effectively compete with native shrubs shadscale, viscid rabbitbrush, and Shockley's buckwheat or native perennial grasses Indian ricegrass and galleta. Where the soil surface was disturbed by rodent activity or, judging by presence of a dense bunch of cheatgrass down inside the burrow, where a more mesic micro-environment had been created ethese Eurasian invaders made themselves right at "home on the range".

Shelford (1963, p. 267) noted that cheatgrass sometimes grows from grain stored by Ord's kangaroo rat in "surface caches".

What, if any, impact these alien weeds had on native range plants (or the facilitating kangaroo rat) was unknown. Occurrence of these two species on the range increased biodiversity (not necessarily the kind that native plant enthusiasts welcome) and both--weeds though they are--periodically provide forage for grazing animals. It is also probable that these naturalized annuals stabilize soils and reduce soil erosion on the range.

Shadscale-dominated salt desert scrub on an alkaline sink. Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

12. Actors on a sink stage- Species composition of a salt desert range was presented in this and the next photograph. On the alkaline sink shown above the potential natural vegetation was probably a shadscale-Indian ricegrass shrubland. This particular range had probably been degraded resulting in increased cover (greater invasion) of viscid rabbitbrush to the degree that this shrubby composite rather than Indian ricegrass was the associate species. Individual plants of these three species were shown in this sample of the sink or large depression on one of many basins in the Great Basin. The large central shrub is shadscale and the bright-green shrubs are viscid or Douglas rabbitbrush. All visible grass was Indian ricegrass.

While Indian ricegrass was locally dominant the overall dominant grass on this range was galleta. It is possible that grazing in decades before this view had resulted in reduced cover of Indian ricegrass, the likely climax dominant for this range site, and increased cover of galleta. Current grazing mangement was allowing persistence of both grasses on this range that was part of a public land allotment being managed in a five-pasture specialized grazing system (explained above).

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, most Indian ricegrass is soft-dough grain stage..

 

13.Other actors on the sunken stage- Galleta was in anthesis alongside a dormant or dead shrub of unknown species on an alkaline sink supporting a salt desert shrub community dominated by shadscale with viscid rabbitbrush as associate shrub species. Climax range vegetation for this range site appeared to be shadscale-Indian ricegrass shrubland, but the "more like" shadscale-galleta shrubland was also recognized as a plant association in the National Vegetation Classification for Nevada (Nevada Natural Heritage Program, 26 September, 2003) which was used for this part of western Utah.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, anthesis in galleta.

 

14. Most made it- Galleta growing on a range that was part of a five-pasture combination deferred rotation-rest rotation grazing system (details presented above in captions that introduced the shadscale-viscid rabbitbrush-Indian ricegrass-galleta and the mixed shrub Great Basin range plant communities).

Clearly, degree of use hand not been excessive up to this point in the galleta growing season. Most shoots bore full-flower inflorescences. Life mission complete for the shoot that produced fruit.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, anthesis in galleta.

 

15. Great Basin wind (and anemophily vs. anemorchory)- This wind-blown inflorescence of galleta gave testimony to the fact that most grass species (and grasslike plants such as sedges and rushes also) are pollinated by wind. This form of pollination in which wind is the pollinizing agent is anemophily . Dispersal of seeds and spores (also the cases for most grasses and grasslike plants) is anemorchory. Galleta is eragrostoid grass, most of which are regarded as having the raceme type inflorescence. Hilaria species play a trick on agrostologists by having sessile spikelets arranged in units of three all spikelets of which are shed together in this unit that is termed a spike or fascicle. Some agrostologists refer to the Hilaria inflorescence as a bilateral spike.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

16. In sink- Winterfat (left) and shadscale (right) growing on an alkaline sink as members of a Great Basin salt desert shrub range. This was one of five ranges in a combination deferred rotation-rest rotation grazing system on a public land allotment.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

17. Shadscale, also known as spiny saltbush or salt sage, (Atriplex confertifolia)- Shadscale is co-dominant with black greasewood of salt desert shrub range in Great Basin and Mojave Desert and adjacent range. Other important shrubs included viscid or Douglas rabbitbrush, winterfat, Shockley's buckwheat, and bud sagebrush. Major native grasses were galleta and Indian ricegrass. These specimens were growing on alkaline sink that was part of a large basin near Sevier Lake (Sevier Lake hydrologic basin) in western Utah.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

18. Details of shadscale- Photographs to show characteristics of leader (shoot or main limb), leaves, and immature bark of one of the most important (commonly a dominant) shrub of Great Basin Desert. The smooth, gray branches that have numerous terminal spines is a fast on-the-range identifying characteristic. The gray-green oval- to elliptical-shapped leaves are another field identification feature.

Leaves and terminal parts of twigs serve as browse for most range ungulates, livestock and wildlife. Shed leaves of shadscale blow into small piles and these are readly eaten by sheep, cattle, and, presumedly, game species (Dayton, 1931,ps. 30-31). The present author has consistenly referred readers to the Range Plant Handbook for particulars in regards to major range species. Shadscale was no exception: Forest Service (1940, ps. B28). Shrubs of the Great Basin included an outstanding treatment of shadscale (Mozingo, 1987, ps. 52-59). In fact, Monzingo (1987) is one of the finest references available for beginning students of Great Basin range vegetation.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

I

19. Winterfat or, sometimes, white sage (Eurotia lanata= Ceratoides lanata)- Winterfat is another major (frequently dominant) shrub of the Great Basin Desertscrub. Winterfat was treated below in a section of its own. These two examples were growing on an the alkaline sink in the greater Sevier Lake basin used as example of shadscale-Indian ricegrass range type.These two plants were included to provide more nearly complete coverage of species composition ocharacteristic of many shadscale-dominated salt desert ranges.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, full-flower phenological stage.

 

20. Bud sagebrush or, simply, budsage (Artemisia spinescens)- This sagebrush species differs noticeably from its Artemisia brethern of the Great Basin and sagebrush steppe ranges. Tueller (1975, p.6) pointed out tht bud sagebrush is a semiprostrate, non-tridentate Artemisia species. Bud sagebrush has terminal buds that look like odd-shaped buttons on the small fan-appearing shoot tip. As much if not more conspicuous is the deciduous feature of budsage which sheds its leaves in mid to late summer.

Budsage is a valuable browse plant, but it has caused livestock poisoning under certain conditions.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

21. Bud sagebrush up close- These photographs showed the most picturesque and readily detected feature of this species: button-shaped terminal buds arranged so as to have a minature fan-like appearance. The specimens presented here were in full-foliage, but some of their "rangemates" ahd already shed most of their leaves. Leaf-deciduousness is unique among Artemisia species in the Great Basin.

Students were referred to the brief coverage by Dayton (1931, ps. 172-173) and the fine chapter in Mozingo (1987, ps. 265-266)

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

22. Almost surrounded- On the shadscale-dominated range of a alkaline sink that served as an example of the shadscale range type Shockley's buckwheat was second only to viscid or Douglas rabbitbrush as a major shrub species. It was noted that this range was likely an example of shadscale-viscid rabbitbrush grazing disclimax (Tueller, 1975, p. 6). Successional status of Shockley's buckwheat was not known, but its relative abudance made it deserving of a featured place in this lineup of alkali-abiding shrubs and subshrubs.

In this scene four, plants of Shockley's buckwheat encircled a lone shadscale, the local range dominant and a dominant range shrub over much of the Great Basin. This composite snapshot displayed the density and cover of iShockley's buckwheat at local microsites on what was regarded as a shadscale-Indian ricegrass shrubland. Welsh et al (1993, p. 534-552) recognized and described over 50 species of buckwheat (Eriogonum), several of which had six to eight varieties. Most of these are, like Shockley's buckwheat, subshrubs rather than "full-fledged" shrubs.

Eriogonum is one of those genera that could only be loved by taxonomists or fanatics (like varieties of Eriogonum these two groups frequently integrade). Eriogonum is a genus that is characteristic of Great Basin Desert (and sagebrush steppe) range vegetation, and often with such cover that the taxon deserved due coverage.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June.

 

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23. Shockey's buckwheat (Eriogonum shockeyi)- There are many Eriogonum species in the Great Basin, including Great Basin Desert. A shadscale-viscid rabbitbrush disturbance climax on an alkaline sink was used as an example of shadscale-dominated salt desert shrub. Shockley's buckwheat was the third major non-herbaceous species. For that reason it received "expaned coverage" herein.

Typical plants of the perennial Shockley's buckwheat have a rounded or hemispherical habit described by Welsh et al, 1993) as "mound-forming". Most of these plants have a single woody or semi-woody shoot from which short limbs and branches arise. Such a shoot is a caudex, "the woody base of an otherwise herbaceous perennial" (Welsch et al., 1993, p. 932).

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, full-bloom stage.

 

24. Bless that blooming buckwheat- Shockley's buckwheat was in full-bloom on an alkaline sink range in which it was a locally abundant subshrub. On tough and stark-looking range like salt desert scrub rangemen learn to appreciate things of beauty. Bless the buckwheat and fill the canteens.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, anthesis.

 

25. Four-wing saltbush (Atriplex canescens)- This Atripex species has one of the largest geographic ranges and is one of the most adaptable shrubs on the Western Range. Fourwing waltbush was treated in more detail elswhere in this publication (on range types where it is a dominant species), but this relatively large specimen was shown here because it was growing on the mixed-shrub salt desert range that served as an example of one form of the shadscale range type.

Four-wing saltbush is a dioecious species. The specimen "trotted out" above was a male plant.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June, peak anthesis.

 

26. Hispidcress or hairy pepperweed (Lepidium lasiocarpum var. lasiocarpum)- The Cruciferae is not as well-represented on Great Basin Desert range as the Gramineae, Chenopidiaceae, or Compositae, but there are important crucifers--native and exotic--that are important in this range ecosystem. This plant was growing on a alkaline sink in a shadscale-viscid rabbitbrush disclimax of former climax shadscale-Indian ricegrass shrubland.

Hispidcress is a native annual crucifer. It was more common than naturalized Eurasian species tumble mustard or tansy mustard on a salt desert range occupying the alkaline sink that served as an example of the shadscale range type. On mixed shrub-salt desert range adjecent to the sink range site hispidcress was less abundant while tansy and tumble mustards were far more abundant.

Millard County, Utah. Bureau of Land Managfement, Fillmore Field Office. June, termination of annual life cycle (plant dead)..

 
Great Basin Salt Desert Shrubland
Great Basin Greasewood
 

Black greasewood was regarded as a co-dominant with saltbush (Atriplex spp.), especially shadscale (A. confertifolia), as a major subdivision or subunit of Great Basin Desert. The title of "Saltbush-greasewood" was used by Kuchler (1964, 1966) as a "vegetation type" or mapping unit of potential natural vegetation. This title was retained by West (in Barbour and Billings, 1988, p. 217 and 2000, p. 267).

Greasewood has usually been regarded as second to saltbush (specifically sahdscale) especially on more xeric habitats. Shantz (in Tidestrom, 1925, p.19) had the opposite interpretation and designated the Salt Desert Shrub as the Greasewood Formation under which was a Greasewood Association and a Greasewood-Shadscale Association. From his perspective, Shantz (in Tidestrom, 1925, p. 16-17) saw the Shadscale Association as a unit of Northern Desert Shrub.

Although black greasewood and one to several saltbush species frequently grow side-by-side and share dominance, these species also form separate and singularly distinct climax range plant communities. Shelford (1963, ps. 269-271) recognized and described a greasewood faciation, a shadscale faciation, and a winterfat faciation all within the shadscale association. With only one exception Brown et al. (1998, p. 40) recognized each of these plus several others as separate series (ie. Shadscale Series, Saltbush Series, Winterfat Series) under Great Basin Desertscrub. The one exception, and an obvious oversight, was Greasewood Series. There should have been a Greasewood Series with number 152.18. Minus 10 points! All of these species (Series in Brown et al.1998, p. 40) were lumped together under one Society for Range Management rangeland cover type (Salt Desert Shrub SRM 414) by Tueller (in Shiflet, 1994).

Black greasewood takes center stage.

 

27. A greasy floodplain- This lowest end of a basin in part of the Snake Valley that receives water from the Conger Range is frequently (by desert standards) flooded. A black greasewood consociation consisting of only a few other range plant species developed on this low-lying range site. There were relatively few plants of shadscale, viscid or Douglas rabbitbrush, low sagebrush (Artemisia arbuscula), and, least of all, rubber rabbitbrush. The prominent feature of this desert basin vegetation to a rangeman was the almost total absence of any herbaceous species, including cheatgrass and Eurasian crucifers. Exclusive dominance of black greasewood is such that these range plant communities are commonly known as greasewood flats.

The homogenous species composition of this greasewood salt desert scrub was remarkable. Three photographs of "sameness". Imagine human beings with priminitive tools (early white man was not that much better off tool-wise, and skill-wise worse off, than Indians) crossing this stark land. Pull of gold in the Sierra Nevada or better soil near the Pacific Slope must have been strong.

Shelford (1963, p. 271) regarded such greasewood flats as part of the Greasewood-Harvest Mouse Faciation. Shelford's brief description indicated that this was critical habitat for numerous species of smaller wildlife, including black-tailed jackrabbits (Lepus californicus), and invertebrates. One can see a long way, but it would be hard to see how anything but jackrabbits, mice, spiders, and fast-flying birds could survive on this rangeland.

Millard County, Utah. Bureau of Land Management, Fillmore Field Office. June (and to think that summer had just begun). FRES No. 30 (Desert Shrub Shrubland Ecosystem). K-34 (Saltbush-Greasewood). Greasewood variant of SRM 414. No Brown et al. (1998, p. 40) biotic community, but should be Greasewood Series 152.18 of Great Basin Desertscrub 152.1. Sarcobatus vermiculatus (Intermittently Flooded) Shrubland (Nevada Natural Heritage Program, 26 September, 2003). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13b (Woods et al., 2001).

 

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28. Now this is more like it (well, kinda)- Black greasewood-Indian ricegrass salt desert shrubland. These three photographs presented greasewood-dominated desert at its finest-- from a rangeman's point of view. Indian ricegrass, one of the Great Basin's dominant climax grasses, accompanied by galleta and, at much less cover, needle-and-thread (two other climax species) formed an interrupted herbaceous layer in this shrubland. Other but clearly subordinate shrub species included both viscid and rubber rabbitbrush, spiny hopsage, shadscale, and small cover of Wyoming big sagebrush.

This range plant community was climax--or near it--vegetation. Near absence of cheatgrass and annual Eurasian crucifers attested to the high successional status of this range vegetation.

Observe in the third slide how Indian ricegrass ocurred in a distinct "ring" around the large mound produced by harvester ants. Harvester ants maintain a clear area that is devoid of plant life in the immediate vicinity of their nest site. Harvester ants undoubtedly also rely heavily on grains of Indian ricegrass (as did North American aborigines whose use of this festucoid/stipoid grass is indicated by its common name). Perhaps ants dropped grains of ricegrass at perimeter of their nest site resulting in the "hedge" or "shelter-belt". Water that was shed from the conical mound of earth would have been availaable as a form of natural "irrigation" for ricegrass. This grass would then set grains which would be available for ants. If something like this herbivorous activity (coaction was the Clementsian term) occurred it would be a form of mutualism.

Cole (1932, ps. 140-14) described the denuded area around western harvester ant mounds. He remarked tht there were "a few scattered grasses" like species of Agropyron and Stipa "...growing near the periphery of the circle". Numerous workers have been intrigued by the natural history and ecology of western harvester ants. Enter "western harvester ant" into Goggle and be amazed at the study that has been made of this social insect.

Beaver County, Utah. Bureau of Land Management, Cedar City Field Office. June, estival aspect (anthesis stage in greasewood). FRES No. 30 (Desert Shrub Shrubland Ecosystem). K-34 (Saltbush-Greasewood). Greasewood variant of SRM 414 (Salt Desert Shrub).Should be Greasewood Series 152.18 of Great Basin Desertscrub 152.1 of Brown et al. (1998, p. 40). Sarcobatus vermiculatus / Achnatherum hymenoides Shrubland (Nevada Natural Heritage Program, 26 September, 2003). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13b (Woods et al., 2001).

 

29. Quilt on the desert- No, not exactly a blanket of lush foliage, but this patchwork of salt desert vegetation provided one of the traditional lessons of Desert Ecology. Climax range vegetation had developed in local zones on a halosere, "a characteristic sequence of communities associated with the developmental stages in plant succession on salt marshes or salt desert" (Allaby, 1998). This zonation of vegetation development was along areas of increasing soil salinity aligned varying distances from the shore of Great Salt Lake.

This resulting mosaic of halophytic range plant communities represented an example of "vegetation writ small", a compressed-into-a short-distance, life-zone-like assemblage of halophytes. Halophyte refers to "a terrestrial plant that is adapted morphologically and/or physiologically to grow in salt-rich soils and salt laden air"; the adjective halophytic means "thriving in, or preferring to grow in, the presence of salt" (Allaby, 1998).

The halophytic climax range vegetation shown here and expained in the series of slides below has been a long-standing, "textbook example" of plant succession processes, vegetation development, and resultant plant communities. In the classic Flora of Utah and Nevada Shantz (in Tidestrom, 1925, p. 19-21) described zonal halophytic vegetation of the salt desert shrub in the Clementsian association/associes model. Flowers and Evans (1966) presented a similar halosere for the Great Salt Lake vicinity which was shown by West (in West, 1983, p. 389; in Barbour and Billings, 1988, p.221 and 2000, p.270). Students can go to these references and use the halosere diagrams as a guide ("road map") by which to follow the scenes of halophytic range plant communities that followed. Tueller (1975, p. 26) also presented a diagramatic halosere, but it was not as appropriate for this Great Salt Lake halosere.

All of these halophytic range plant communities were seen as climax vegetation. Shantz (in Tidestrom, 1925, ps. 19-21) used the original monoclimax model of Frederick E. Clements to describe the Salt Desert Shrub (perhaps the first usage and original literature source of this designation). Shantz interpreted the greasewood- and samphire-dominated range communities as Clementsian associations (ie. greasewood association, samphire association) while he regarded saltgrass grassland as the seral unit of associes (ie. saltgrass associes). In the original Clementsian model of plant succession any vegetation that was not determined primarily or ultimately by climate was seral. In the monoclimax model any plant communities that developed on land receiving more water than provided directly by precipitation (eg. most wetlands like marshes and riparian, floodplain, or other overflow water-derived vegetation) would be seral and regarded as a Clementsian associes. Thus designation of saltgrass associes by Shantz (in Tidestrom, 1925, ps. 19-21). Under polyclimax theory saltgrass semidesert grassland is climax range vegetation.

The mosaic of range plant communities were of different range types or variants of range types, alliances, associations, biotic communities, or zones depending on reference(s) referred to. These Lilliputian-sized units of range vegetation were too small to be described by such large-scale vegetation mapping units as those of Kuchler (1964, 19660 or Garrison et al. (1977). The halosere extended from the shore of Great Salt Lake inland to a semidesert grassland with a transition plant community between that was a shrubland dominated by black greasewood and having a sparse, herbaceous understorey.

The vegetation in the foreground (low-growing, shining-green color) was of the succulent halophytes Utah samphire (Salicornia utahensis) with small amounts of seepweed (Suaeda spp.), occasional plants of iodinebush or pickleweed (Allenrolfea occidentalis), and desert saltgrass (Distichlis stricta= D. spicata var. stricta= D. spicata), Immediately behind the samphire-saltgrass community "patch" was a consociation (a population-level stand) of Indian ricegrass (tan or fawn-colored vegettion of mid-height). Background was black greasewood scrubland.

Backshore of Great Salt Lake Tooele County, Utah. June.

 

30. Closer to the halophytic patchwork- Nearer to the range plant communities introduced in the immediately preceding slide: a diagonal view across the Indian ricegrass stand (left; tan-colored plants) and Utah samphire-seepweed community (right; bright green and gray-colored plants) with greasewood scrubland in background.

Backshore of Great Salt Lake, Tooele County, Utah. June, early estival aspect..

 

31. Black greasewood salt desert- Two sweeping views of a salt desert shrubland with both a shrub and an herbaceous layer (if they could be called layers by streatch of imagination). Climax range plant community on part of a halosere that went from the shore of Great Salt Lake inland to a desert saltgrass semidesert grassland. Dominant species of this salt desert shrubland was black greasewood which, with associate shrub, viscid or Douglas rabbitbrush, comprised the woody layer. The herbaceous layer consisted of local stands of Indian ricegrass and local assemblages of desert saltgrass, Utah samphire, seepweed, and scattered plants of iodinebush or pickleweed. Different patches of saltgrass and samphire varied in which species prevailed in this herbaceous group. Seepweed was sparse (and about as much dead as alive). As always there was cheatgrass, but it was not associated with any particular species or local group of plants. Relative scarcity of cheatgrass was indicative of the climax (at least high seral stage) of this range vegetation.

This range had been grazed by cattle within two months of this series of photographs.

The entire halosere of climax range vegetation could be regarded as FRES No. 30 (Desert Shrub Shrubland Ecosystem) with an appropriate Kuchler "vegetation type" being number 34 (Saltbush-Greasewood). "Super-salty" greasewood variant of SRM 414 (Salt Desert Shrub). Part of this halosere was Sarcobatus vermiculatus / Distichlis spicata Shrubland (Nevada Natural Heritage Program, 26 September, 2003). If the classification system of Brown et al. (1998, p. 40) had not inadverdently omitted it this would be the Greasewood Series 152.18 of Great Basin Desertscrub 152.1. Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13b (Woods et al., 2001).

Tooele County, Utah. June, early estival aspect..

 

32. Salt pals- This 'photo-quadrant" of a greasewood-samphire-grass salt desert shrubland included the following species: black greasewood, viscid or Douglas rabbitbrush, Utah samphire, Indian ricegrass, cheatgrass or downy brome, plus an unknown forb in the right foreground.

Tooele County, Utah. June, early estival aspect. FRES No. 30 (Desert Shrub Shrubland Ecosystem). K-34 (Saltbush-Greasewood). "Super-salty greasewood vriant of SRM 414 (Salt Desert Shrub). Would be Greasewood Series 152.18 of Great Basin Desertscrub 152.1 of Brown et al. (1998, p. 40). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13b (Woods et al., 2001).

 

33. Salty dogs- Utah samphire with some amount of seepweed at local- or microsite-scale on a greasewood-herb salt desert shrubland. These species typically grew farther inland from the shore of Great Salt Lake. Many of these microhabitats are the most saline parts of the halosere due to accumulation of water from Great Salt Lake and internal drainage which upon its evaporation leads to extreme soil salinity.

Tooele County, Utah. June.

 

34. Iodinebush or, sometimes, pickleweed (Allenrolfea occidentalis)- This subshrub is typically one of the dominant range plants of salt flat deserts or the salt desert shrub range community, especially at edges of saline playas, basins, and shores of Great Salt Lake. At this location iodinebush was scarce and such as incidenetal range plant that it was important primarily as an indictor species. It was presented here for that purpose. The dark or brown coloration of lower shoots was typical. Shoots of this species are succulent (like those of Salicornia species), but older and larger shoots of iodinebush become woody or, at least, semi-woody.

Outer shore of Great Salt Lake, Tooele County, Utah. June.

 

35.Another ant hill- Mound and denuded area of western harvester ant. Indian ricegrass and desert saltgrass were thriving (by salt desert criteria) at perimeter of the ant-maintained "clearing" around their home. Viscid or Douglas rabbitbrush in background. Brief discussion of harvester ants herbivory was provided above. (We're into harvester ants on this program.)

Tooele County, Utah. June.

 

36. Edge of the salt pond- Innermost shore of Great Salt Lake where the salt desert shrub was primarily individual plants of black greasewood (and these were extremely sparse). Utah samphire and desert saltgrass were also present. Thus the species composition was similar to tht further inland except that Indian ricegrass, viscied rabbitbrush, and cheatgrass "gave it up". So had the harvester ants.

Salt had accumulated on the soil surface where puddles of water evaporated. Cattle had grazed this range less than two months after this series of slides was taken. No, not much to eat but look at it this way: would not have to put out salt.

Tooele County, Utah. June. FRES No.30. K- 34 (Saltbush-Greasewood). Greasewood variant of SRM 414 (Salt Desert Shrub). Would be Greasewood Series 152.18 of Great Basin Desertscrub 152.1 of Brown et al. (1998, p.40)-- if they had not forgotten it. Sarcobatus vermiculatus / Distichlis spicata Shrubland (Nevada Natural Heritage Program, 26 September, 2003). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13b (Woods et al., 2001).

 

37. Utah samphire (Salicornia utahensis)- This succulent chenopod is a perennial herbaceous plant. Utah samphire was the dominant range forb in the understorey of a greasewood-herbaceous salt desert shrubland. It grew in local patches as did the native perennial grasses, Indian ricegrass and desert saltgrass, with which it alternated as the dominant herbaceous species of this range vegetation.

Tooele County, Utah. June.

 

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38. Useful (barely) for something even in death- On a salt desert shrubland dead wood of a black greasewood supported growth of lichen. Range vegetation had a remarkable botanical diversity given the relatively few plant species present. Also remarkable is the extreme diversity of environments under which lichen, the smybiosis of alga and fungus, can thrive. Whenever possible the author introduced the student to the amazing world of lichens.

Tooele County, Utah. June.

 
Follow wherever it leads so there is no unfinished business or loose ends ...

39. Saltgrass semidesert grassland- Where shore of Great Salt Lake petered out and encountered a mountain range (ie. where basin met range) the range had developed into an actual grassland dominated by desert or inland saltgrass. Associate species was Utah samphire. There was absolutely no black greasewood or any shrubs of any species, period. Nor was there any cheatgrass. (Range on the mountain was bluebunch wheatgrass [Agropyron spicatum]-dominated bunchgrass steppe.)

This range had been heavily grazed by cattle less than two months before this photograph was taken. Next slide, please.

 

40. "Reckon we got it all?"- View of range sward of desert saltgrass semidesert grassland on which Utah samphire was associate species. Heavy degree of use (bordering on severe utilization) of saltgrass by beef cattle. This was a growing season of roughly average precipitation (or a little above average) causing one to wonder if this range has been grazed this heavily in other years. If so, the desert saltgrass had persisted unbelieveably well. Otherwise this range would have (or will) become a "nice" stand of Utah samphire.

Heavy degree of use was obvious,but this was also guaged by comparison to ungrazed desert saltgrass outside this pasture. That and other details of the desert saltgrass range type were presented in the Semidesert Grassland (Great Basin) chapter elsewhere in this book.

Tooele County, Utah. June, hard-dough stage in desert saltgrass. FRES No. 40 (Desert Grasslands Ecosystem). No Kuchler or SRM units for saltgrass grassland. Kuchler (1964, 1966) did not have mapping units for "vegetation types" that were present at such small scale. Society for Range Mnaagement (Shiflet, 1994) probably could found noone to write a description for what should have been Desert Saltgrass rangeland cover type. Distichlis spicata (Intermittently Flooded) Herbaceous Vegetation or Distichlis spicata (Intermittently Flooded) Mixed Herb Herbaceous Vegetation (Nevada Natural Heritage Program, 26 September, 2003). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 134 b (Woods et al., 2001).

 
.41. Salt desert scrub- Greasewood-shadscale-four-wing saltbush salt desert type. This range vegetation represented a greasewood variant of the Great Basin-Colorado Plateau mixed shrub desertscrub because black greasewood was the dominant species. While the natural plant community presented here was in the Colorado Plateau physiographic province it was seen part of the greater Great Basin Desert. (Less obvious "islands" of Great BasinDesert were treated below under the Marginal Contacts section.). The understory included both cheatgrass and native perennial grasses like inland saltgrass and scatted plants of smooth bromegrass, an introduced perennial remarkably common on this floodplain of the Green River. Numerous composite species especially, of course, Artemisia.Red Desert of Wyoming, Sweetwater County. FRES No. 30 (Desert Shrub Ecosystem). K-34 (Saltbush-Greasewood). SRM 414 (Salt Desert Shrub). A composite of Shadscale Series and Saltbush Series of Brown et al. (1998).
 
42. Greasewood- Another chenopod shrub that is a dominant on various range sites throughout the desert scrub communities of the Great Basin as well as along drainages and bottomland grasslands in the Great Plains. Crowley County, Colorado, July.
 
43. Greasewood- Leaves and staminate flower clusters of greasewood. Crowley County, Colorado, July.
 
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44. Black greasewood-Sandburg bluegrass range- In a transition zone between the High Lava Plains and Basin and Range Provinces (Franklin and Dyrness, 1973, p. 6) this upper storey consociation of black greasewood and understorey of Sandberg bluegrass (Poa secunda= P. sandbergii) formed a relatively simple plant community that afforded range for both livestock and big game-- inhospitable and unappealing as it might appear to human senses. As cited in the preceding caption, Franklin and Dyrness (1973, ps. 227, 245) designated a black greasewood-inland saltgrass community for central and eastern Oregon. These workers made no reference to a greasewood-Sandberg bluegrass community or variant of the former community, but that was clearly the vegetation presented here. In fact, this photographer observed no saltgrass on the range portrayed here. Rather Sandberg bluegrass held forth as essentially the only graminoid species. There was some scattered cheatgrass (Bromus tectorum) but it would rank a weak associate species. (Refer to two slides immediately below.) Neither were Carex species encountered on this range in this typical precipitation year.

Malheur National Wildlife Refuge, Harney County, Oregon. June. Estival aspect. FRES No. 30 (Desert Scrub Ecosystem) but no appropriate Kuchler unit for natural plant communities of this scale. Kuchler unit 34 (Saltbush-Greasewood) is "as close it gits" and that does not reflect those plant communities that are greasewood consociations. Furthermore, the description of this unit (Kuchler, 1964, unit 40 therein) included no grasses or grasslike plants. Kindly note again comment on incompleteness of vegetation designations and mapping given in preceding caption. SRM 414 (Salt Desert Shrub). Mixed Scrub Series of Brown et al. (1998). Sarcobatus vermiculatus Shrubland (Nevada Natural Heritage Program, 2003).

 

45. Species composition of black greasewood-Sandberg bluegrass range plant community- In addition to the dominant shrub and herbaceous species a specimen of cheatgrass was represented in this photograph. Cheatgrass was widely scattered and a search was necessary to find cheatgrass and the dominants within the same "frame". Transition zone between High Lava Plains and Basin and Range provinces (Franklin and Dyrness, 1973, p. 6), but this range vegetation clearly had physiogonomy, structure, composition more that of the Great Basin Desert than of a shrub steppe, the major expression of vegetation in this area.

Malheur National Wildlife Refuge, Harney County, Oregon. June. FRES No. 30 (Desert Scrub Ecosystem) but no apt Kuchler unit (K-34 was "closest fit"). SRM414 (Salt Desert Shrub). Mixed Scrub Series of Brown et al. (1998). Sarcobatus vermiculatus Shrubland (Nevada Natural Heritage Program, 2003).

 
46. Sandberg bluegrass- Mature (seed-ripe stage) Sandberg bluegrass in understorey of black greasewood-dominated scrub range. Although this range vegetation was at extreme northern edge of the Great Basin (more as an "island" thereof) it was reasonable typical of the Great Basin Desert type. Malheur National Wildlife Refuge, Harney County, Oregon. June.
 
Great Basin Salt Desert Shrubland
Great Basin Winterfat
 

Winterfat or white-sage (Eurotia lanata= Ceratoides lanata) is a defining and, frequently, a dominant range shrub in the Great Basin Desert. Winterfat is not as widespread as several Great Basin shrubs but is both 1) a major climax dominant and 2) major browse plant over such a large area that it perhaps second only to shadscale and greasewood as a determinant for a range cover (= dominance) type. For comparison viscid and rubber rabbitbrush grow about everywhere in the Great Basin and adjacent vegetation regions like sagebrush-bunchgrass steppe, but these rabbitbrush species are almost never dominant, at least over any appreciable area of natural range vegetation. Similarily, fourwing saltbush is regarded as the most widely distributed Atriplex species in North America, but it is not a dominant range plant across as much rangeland as is winterfat.

Winterfat is a perennial chenopod. It is a textbook example of subshrub or, in more botanically correct terms, a suffruticose shrub. The adjective suffruticose means "woody; diminutively shrubby" (Welsh et al. 1993, p. 940) In simplied language a subshrub has a perennial shoot that is woody for some distance above the soil surface (ie. partially woody or simi-woody). Subshrubs produce annual, herbaceous branches and side-shoots above the somewhat woody basal stem. These annual leaders (rangeman and forester term for a woody shoot, usually limb or branch not main shoot or trunk) with their leaves and terminal twigs are the source of nutritious browse.

Winterfat often occurs as a consociation to such exclusion of other range plants that it forms natural single-species stands that produce tremendous quantities of high-quality browse. The nutrient-richness of winterfat is retained even in necromass (dead phytomass) and throughout plant dormancy making this species ideal for winter range (hence origin of the standard common name). Value of winterfat as a major source of natural, readily available winter feed is further enhanced by the fact that much of the Great Basin rangeland dominated by winterfat lacks both surface water and groundwater. This unfortunate situation forces the expensive and laborous task of water-hauling for livestock.

Enter snow and sheep. "Stupid" sheep instinctively eat snow when thirsty. When snow is on the ground and sheep are on the range hauling water is not necessary. Winterfat is ideal winter feed. Ergo: winterfat-dominated range is winter sheep range. Two of the Four Cardinal Principles of Range Management are dictated by one species of range plant: 1) Proper Season of Range Use and 2) Proper Kind and/or Classs or Range Animal.

Winterfat is also extremely valuable for native ruminants. Elk or wapiti (Cervus canadensis= C. elaphus) are reportedly especially fond of and do well on winterfat range.

Winterfat is also an important--typically an associate--species on Great Basin semidesert grasslands, especially those dominated by Indian ricegrass. Winterfat was also treated in the chapter, Semidesert Grassland (Great Basin).

Readily read, practical references on winterfat are: Dayton (1931, p. 31-33), Forest Service (1940, p B76), Sampson and Jespersen (1963, 67-68), and Mozingo (1987, ps. 67-72)67-68.

 

47. Stark beauty in the desert- Two views of a magnificant stand of winterfat across a large basin in the in the Basin and Range physiographic province. In spite of spacious intershrub spaces there were few other plant species on this "pure" consociation of winterfat. Cheatgrass and Eurasian crucifers were absent other than to "make the list". Likewise, native perennial grasses such as needle-and-thread, galleta, alkali sacaton, and even the general dominant Indian ricegrass were basically missing from this range plant community tht was more like a population of winterfat.

Snake Valley in White Pine County, Nevada. June, immediate pre-bloom to early bloom phenological stage. FRES No. 30 (Desert Shrub Shrubland Ecosystem). For whatever reason, Kuchler (1964, 1966) did not have a vegetation unit for winterfat. Also, the Society for Range Management did not have a winterfat (nor a greasewood, shadscale, saltbush, etc.) rangeland cover type but instead Tueller (in Shiflet, 1994) wrote a generic "big tent" Salt Desert Shrub (414). Hence, this was a variant of SRM 414. Brown et al (1998, p.40) provided more specific designations for biotic communities: Winterfat Series 1152.15 of Great Basin Desertscrub 152.1. This is a winterfat form of the Winterfat-Ricegrass-Kangaroo Mouse Faciation of Shelford, 1963, p. 271-273). Krascheninnikovia lanata Dwarf-shrubland (Nevada Natural Heritage Program, 26 September, 2003). Central Basin and Range- Shadscale-dominated Saline Bsins Ecoregion, 13b (woods et al., 2003).

 

48. Another basin overflowing with winterfat- A winterfat range ecosystem on an extremely xeric range site. This browse range was grazed by cattle and pronghorn (Antilocarpa americana). The latter were plentiful (but not particularily fat) during summer on this winterfat-flat range. This winterfat consociation had very little cover of native grasses or forbs other than enough to check them for species presence on the plant list. There was only slightly more cover or density of cheatgrass, tumble mustard, and pinnate tansy mustard than on the winterfat flat presented in the immediately preceding slides.

Great shrubland range in "God's Country". Snake Valley, Millard County, Utah. June. Same range ecosystem (FRES No. 30), rangeland cover type (winterfat variant of SRM 414, Salt Desert Shrub), Brown et al. (1998, p. 40) biotic community (Winterfat Series 152.15, Great Basin Desertscrub, 152.1), and Nevada Natural Heritage (26 September, 2006) association (winterfat dwarf-shrubland) as those on the other side of the stateline shown immediately above.

 
The following series of three slides were taken from the famous Desert Range Experiment Station, Millard County, Utah (June, early summer). The four "photo-plots" gave some indication of local variation in a winterfat-Indian ricegrass-viscid rabbitbrush shrubland. Any one of these three range plant species could be declared "dominant" depending on where, how big, how long, how many, and what shape the quadrants or transects and what vegetation criteria (eg. basal or aerial cover, density, biomass) were used to determine species composition. Good example for the course in Range Analysis.
 
49. Pristine to the eyes of a desert rat rangeman- Dwarf shrubland of winterfat and Indian ricegrass. Nearly picture-perfect example of the Krascheninnikovia lanata / Achnatherum hymenoides Dwarf-shrubland (Nevada Natural Heritage Program, 26 September, 2003) which was an exact descriptive designation of this climax range vegetation. The whole herd of such ecosystem, rangeland cover type, association, ecoregion, etc. was listed at end of this four-slide set.
 

50. Shearest beauty on a Basin and Range range- These two examples (one emphazing range landscape; one featuring species composition of range vegetatione) presented a range plant community in which winterfat, Indian ricegrass, and viscid rabbitbrush shared the desert soil and formed a grass-dwarf shrub desert or, if preferred, a dwarf shrubland with a grass understory. Successional status of viscid or Douglas rabbitbrush was unknown. Clearly winterfat and Indian ricegrass were climax dominants. Examples of the Winterfat- Ricegrass-Kangaroo Rat Faciation of Shelford, 1963, ps. 271-273).

This range had been grazed by sheep under the most superb management for several decades. It was shown to Range Management students as an example of extraordinary stewardship as well as an example of one form of Great Basin Desert.

Desert Range Experiment Station. Millard County, Utah. June, early estival aspect.

51. Grassland, shrubland, grass-shrub savanna, or something else- In this view of an overall winterfat-Indian ricegrass-viscid rabbitbrush range plant community Indian ricegrass was the obvious dominant whether by aspect dominance, foliar cover, density, or biomass measurements. If this "segment" of the range plant community was sampled and used as basis from which range condition class, grazing management, etc. was judged the result would be somewhat different than if the "segment" of the two immediately preceding slides was sampled and used as basis for evaluation. Most difference would be due to different amounts of viscid rabbitbrush.

Physiogonomy and life form varied enough that this range vegettion could be described as Indian ricegrass-grassland or winterfat-Indian ricegrass dwarf shrubland depending on which plots and transects were emphasized (and the biases and background experiences of the rangeman doing the description). This was a valuable lesson for beginning range students to grasp.

It was beautiful, well-managed desert range either way.

Desert Range Experiment Station, Millard County, Utah. June, early estival aspect. FRES No. 30 (Desert Shrub Shrubland Ecosystem). No Kuchler unit of vegetation (for unknown reasons). Winterfat variant of SRM 414 (Salt Desert Shrub). Winterfat Series 152.15 of Great Basin Desertscrub biotic community 152.1 (Brown et al., 1998, p. 40). Ceratoides lanata / Oryzopsis hymenoides (Bourgeron et al., 29 August, 1994). Krascheninnikovia lanata / Achnatherum hymenoides Dwarf-Shrubland (Nevada Natural Heritage Program, 26 September, 2003). Central Basin and Range- Shadscale-dominated Saline Basins Ecoregion, 13b (Woods et al., 2001).

 

52. Winterfat (Eurotia lanata= Ceratoides lanata)- General habit (first slide) and shoot details (second slide) of winterfat in Snake Valley, White Pine County, Nevada, Bureau of Land Management, Ely Field Office and Millard County, Utah, Bureau of Land Management, Fillmore Field Office, respectively. June. Both plants at full-bloom phenology.
 

53. Winterfat shoots (from last and this year)- Shown here were dead shoots from previous growing season along with live shoots from current growing season on a winterfat plant. The suffruticose feature of winterfat is characterized by the pronounced feature of "numerous annual branchlets" (Welsh et al., 1993, p. 136). The winterfat plant featured here had not been browsed (at least noticably so) during the last two growing seasons.

Snake Valley, White Pine County, Nevada. Bureau of Land Management, Ely Field Office. June, pre-bloom stage in the live leader; dead stage from previous growing season..

 

54. Details of winterfat shoots- Leaves and flowers along with telltale, cottony "fuzz" of winterfat at full-bloom phenological stage.Welsh et al. (1993, p. 136) described this pubescence as "... stellate-hairy, commonly with longer straight hairs intermixed, the hairs white or becoming yellowish in age". Dayton (1931, p. 31) explained that winterfat herbage "... is densely beset with rather long, matted, branched hairs, whitish at first and latr rusty".

Incidentially, is the phytomass of winterfat more accurately regarded as "herbage" or "browse"? Think about it. Yes, winterfat is universally called a range "browse plant". Yet most authors refer to actual plant material as "herbage". Parts of this subshrub (suffruticose species) that are eaten are annual because only basal portions of stem are perennial. (If perennial parts are consumed by range livestock and/or big game it is "taps" for winterfat as well as for the animals, including the range businessman).

Snake Valley, Millard County, Utah, Bureau of Land Management, Fillmore Field Office.

 
55.Winterfat scrub- A consociation of this valuable browse species is another major form or section of Great Basin Desert. It is excellent winter range particularly for domestic sheep (Ovis aries), mule deer (Odocoileus hemionus), and pronghorn (Antilocapra americana). Single-species stands such as this one provide quality winter range, but frequently have been overbrowsed. Southern Utah. December. No Kuchler unit for this form of FRES No. 30 (Sagebrush Shrubland Ecosystem), but it is likely be a variant of K-32 (Great Basin Sagebrush). Winterfat variant of SRM 414 (Salt Desert Shrub). Winterfat Series of Brown et al. (1998).
 
Marginal Contacts of Great Basin Desert
(related and associated shrublands)
 

The Great Basin Desert, Great Basin Desertscrub, Great Basin Arid Shrubland, and other such designations define potential natural vegetation that has long been used as native grazing land by the Great Basin portion of the Basin and Range physiographic province. Students of range vegetation learn quickly (maybe some realize innately) that native plant communities, be they of formation-scale or all the way down to that of local microsite, do not conform strictly to physiographic features anymore than to edaphic, climatic, pyric, zootic, or any number of other factors.

There is range vegetation outside of the Great Basin or even of the greater, generic or poetic Great Basin Region that resembles closely (perhaps it is essentially the same as) Great Basin Desertscrub more than the "average" or "typical" native vegetation of the physiographic province, climate, soils, etc. of the general ecological region of what, strictly speaking, it is a part. Such natural range plant communities are, of course, ecotones (ecological transition zones) or, sometimes, if not transitional or graduational, they simply "fit" more closely with another plant formation, association, dominance type, etc.

One such case that was discussed at various junctures above is distinction between the major vegetation unit of sagebrush shrubland or desert (Great Basin sagebrush) and that of sagebrush-bunchgrass savanna (sagebrush shrubsteppe) with even the formal titles (Kuchler, 1964, 1966; West in Barbour and Billing, 1988 and 2000) now widely accepted and adopted. Marginal contacts between Great Basin and Colorado Plateau and between Great Basin and Columbia Plateau are a vegetational "no man's land" with some ecosystem or landscape functions and certain plant community features resembling more closely the native vegetation of one or the other physiographic provinces, or maybe seeming to be an "amagamation" thereof. Other "zones of contention" involve parts of the Sierra Nevada or Cascade Range and Great Basin or the land where the Great Basin and Mojave Deserts (both in the Basin and Range province) abut.

Indeed, the Great Basin cover types presented by the Society for Range Managment (Shiflet, 1994, ps. 40-60) included rangeland cover types that were not wholly restricted to the Great Basin and it excluded some obvious rangeland cover types of the Great Basin (eg. Indian ricegrass semidesert grassland, Great Basin marshes and wet meadows).

Presented and discussed below were some of the more important marginal contacts of the Great Basin Desert with shrubland or shrub steppe vegetation of the Columbia Plateau, Colorado Plateau, or Rocky Mountain foothills.

 
56. Big sagebrush-shrub steppe- As discussed in conjunction with Great Basin sagebrush desert, big sagebrush is a component of range cover types that vary from single-species stands to widely scattered plants in grasslands like those of the Palouse country. This scene in Hayden Valley, Yellowstone National Park is an excellent example of sagebrush vegetation included in an extensive unit mapped by authorities like Kckler as the generic "sagebrush type". The botanically rich understory of the community seen here includes bluebunch wheatgrass, Idaho fescue, blue grama, and buffalograss. Numerous composites --both forbs (e.g. Aster species) and low shrubs -- comprised an obvious intermediate layer. July. FRES No. 30 (Sagebrush Shrubland Ecosystem). K-49 (Sagebrush Steppe). SRM 314 (Big Sagebrush-Bluebunch Wheatgrass). Mixed Bunchgrass-Shrub Series in the Great Basin-Grassland biotic community of Brown et al. (1998).
 
57. Plains grassland and high desert blend in a broad ecotone with varying amounts of big sagebrush and various herbaceous communities depending on range site and past management practices. Here Wyoming big sagebrush (Artemesia tridentata wyomingensis), western wheatgrass, squirreltail bottlebrush, blue grama, sand dropseed, ect. form an obvious sagebrush shrub steppe. SRM description lacking: a big sagebrush-western wheatgrass type that should be with the SRM 314, 315, 316 series. Mixed Bunchgrass-Shrub Series in Great Basin-Grassland biotic community of Brown et al. (1998).
 
58. This general range type was noted variously by John E. Weaver and his colleagues, but less than 200 meters away in the same pasture of a BLM allotment was a western wheatgrass consociation form of mixed prairie on a clay soil under grazing by both cattle and white-tailed prairie dog (Cynomys leucurus).Such local variations in species composition across the range show why “expert opinion” as to role and density/cover of woody plants vary from expert-to-expert regarding almost any range cover type that could be interpreted as shrubland or shrub savanna. Moffat County, Colorado. June.FRES No. 29 (Sagebrush Ecosystem). At a larger scale the Kuchler unit is K-49 (Sagebrush Steppe) but most accurately it is a local example of K-50 (Wheatgrass-Needlegrass-[Sagebrush] Shrubsteppe).No specific SRM description, but similar to SRM 610 (Wheatgrass) or 607 (Wheatgrass-Needlegrass), Intermountain equivalent of the Great Plains type. Wheatgrass Series in Great Basin Shrub-Grassland biotic community of Brown et al. (1998).
 
Distinction of Great Basin Desert from Sagebrush Shrub Steppe: A Problematic Exercise

Separation of the big sagebrush form of Great Basin Desert (a cold, high elevation desert) from the sagebrush steppe (a semiarid bunchgrass-shrub savanna) is not a "ready made" distinction. The difference between aridity and semiaridity is often problematic even when some contrasts seem fairly obvious. When annual amount of precipitation is confounded by a routinely dry summer that resembles a "seasonal dought" and with porus soils and parent material of generally low water-holding capacity designating big sagebrush desert versus big sagebrush steppe can be a "tough call".

Transitions in vegetation are commonplace. Indeed, the savanna features of the sagebrush steppe are evidence that this immense range plant community is an ecotone between the Great Basin Desert (the sagebrush form thereof) and the Palouse Prairie. Along the periphery of the sagebrush steppe (especially in the Basin and Range province where steppe comes into contact with desert) there are further transitions (ie. transitions within transitions; ecotonal communities within a larger ecotonal community). One such area is between the Owyhee Upland and Basin and Range provinces. This is north of the Alvord Desert in the upper hills that receive somewhat greater precipitation (mostly snow) due to higher elevation and with some shelter afforded by basin-and-range topography.

An example of big sagebrush-mixed bunchgrass range vegetation in this transition land was shown below. The vegetation approached pristine and was likely of climax composition and structure. It seemed an appropriate way to end the chapter on sagebrush shrub-steppe and take up with the sagebrush desert of the Great Basin.

 

59. Desertlike sagebrush steppe- On land that was transitional between the Owyhee Upland (Owyhee Mountains of the Payette section of the Columbia Plateau province) and the northern Basin and Range province there are higher basins on which the sagebrush steppe has a physiognomy and structure that closely resembles big sagebrush scrub of the Great Basin Desert. These two views of a big sagebrush-mixed bunchgrass steppe were presented as examples of this transition vegetation which is itself within the transition zone, ecotone, of the sagebrush shrub-steppe that is a savanna. The outward appearance of this range plant community resembled that of desert scrub. Big sagebrush desert scrub often lacks an herbaceous understorey or even herbaceous species other than as occasional plants. Features of this vegetation were intermediate between the more xeric big sagebrush steppe and big sagebrush desert scrub.

Native bunchgrass species that had considerable density and/or sizeable cover included bluebunch wheatgrass, squirreltail bottlebrush, Idaho fescue, Sandberg bluegrass, and Indian ricegrass (Oryzopsis hymnoides) in that approximate order without an obvious dominant species. Cheatgrass, a naturalized Eurasian annual, was also common locally, but it did not have the consistent distribution of the perennials.

Wyoming big sagebrush was the dominant shrub with both gray and green or Douglas rabbitbrush as the two associate woody species. The most common forb was tapertip hawksbeard.

Young et al. in Barbour and Major (1995, p.793) concluded that big sagebrush-bluebunch wheatgrass communities were so common and widely distributed that evidence of close ecological relations between these two species was conclusive.

Vale District, Bureau of Land Management, Malheur County, Oregon. June. Early estival aspect. FRES No. 29 (Sagebrush Shrubland Ecosystem). K-49 (Sagebrush Steppe). Variant of SRM 403 (Wyoming Big Sagebrush). Transition between Mixed Bunchgrass-Shrub Series of Great Basin Shrub-Grassland regional formation and Sagebrush Series of Great Basin Desertscrub regional formation of Brown et al. (1998). Artemisia tridentata (ssp. tridentata, ssp. xericensis)/ Pseudoroegneria spicata (= Agropyron spicatum) Shrub Herbaceous Vegetation (Nevada Natural Heritage Prograam, 2003).

 

60. Details of big sagebrush-mixed bunchgrass range- In this closer-in view of the xeric big sagebrush-dominated steppe the general cespitose growth form of the native perennial festucoid grasses and the dispersion of these species was more apparent. Students should understand what is meant by growth form: "morphology of a plant, especially as it reflects physiological adaptation to the environment" (Allaby, 1998). The most abundant grass in this "photo-quadrant" was bluebunch wheatgrass, but squirreltail bottlebrush and Idaho fescue were also represented.

The higher elevation environment with its attendant cooler temperatures and greater precipitation created more mesic and generally less harsh habitats for range plants with the result being vegetation that was less desertic than that of lower elevations in the Basin and Range province. This land along a transition from uplands to lower landscapes had a complex of factors (each along its own gradient) that produced vegetation that was in transition from that which developed under sets of factors generally more favorable to sets of factors generally less favorable for plant life and development of vegetation.

The limited plant residue on the soil surface was also obvious. This is a characteristic feature of shrub-bunchgrass range. Soils of less or lower degrees of development are characteristic of certain forms of vegetation (eg. deserts) and topographic features (eg. steep slopes). Soils of big sagebrush are primarily of the Brown soils, a zonal great group of temperate to cool arid regions and having calcareous layers. These are not soils of deserts.

Vale District, Bureau of Land Management, Malheur County, Oregon. June. Early estival aspect. FRES No. 29 (Sagebrush Shrubland Ecosystem). K-49 (Sagebrush Steppe). Variant of SRM 403 (Wyoming Big Sagebrush). Transition between Mixed Bunchgrass-Shrub Series of Great Basin Shrub-Grassland regional formation and Sagebrush Series of Great Basin Desertland regional formation of Brown et al. (1998). Artemisia tridentata (ssp. tridentata, ssp. xericensis)/ Pseudoroegneria spicata (= Apropyron spicatum) Shrub Herbaceous Vegetation Nevada Natural Heritage Program, 2003).

 

61. Big sagebrush desert range- The Wyoming big sagebrush-dominated range vegetation shown here was on land transitional between Owyhee Upland and Basin and Range provinces (Franklin and Dyrness, ps. 6, 34-38). Although landscape and geologic features were primarily those of the former province, which corresponded closely to the Owyhee Mountains of the Payette section of Columbia Plateau physiographic province (Fenneman, 1931, ps. 236, 244-248 passim), the basic landform of Basin and Range was obviously present. Correspondingly, the range plant community presented here had features common to vegetation of (shared by) both provinces and other features unique or more distinctive to vegetation of only one of these. For example, big sagebrush is the single most common, important, dominant, or defining species of range vegetation across most of the vast region that encompasses even more land than that in the two provinces. Conversely, absence or extremely sparse herbaceous understorey and limited number of herbaceous species is characteristic of arid big sagebrush-dominated communities (= big sagebrush desert scrub) over immense areas of the Basin and Range province, especially large portions of the Great Basin (often known as the Great Basin Desert).

The Great Basin physiographic unit should not be confused with or mistakenly seen as synonymous with Great Basin Desert even though these are one and the same over much of the range in northern portions of the Basin and Range province. The sagebrush (Artemisia sp.) form of Great Basin desert scrub is mostly Wyoming or basin big sagebrush (Artemisia tridentata subsp. tridentata) and typically with rabbitbrush species as associates or even co-dominants. Most of the true sagebrush (again, primarily big sagebrush) desert (ie. arid scrubland) is limited to range in the Great Basin (or greater Greater Basin region) except for outlying "islands" here and there in adjoining sagebrush steppe or even juniper woodland. These are often local edaphic or topographic climaxes within the larger or general climatic climax.

Another (and perhaps the most important from a management standpoint) climax big sagebrush desert is the zootic climax, often a grazing disclimax (disturbance climax) induced by improper range management. Most of the anthropogenic grazing disclimax is traceable to the severe overgrazing when Public Domain land was open range and there has been tremendous improvement in management of these ranges and subsequent improvement in range vegetation. Obviously considerable improvement (increased or higher range condition) remains to be acheived, but secondary plant succession is slow by human time scale in desert vegetation. Making stocking rates (of both livestock and wildlife) consistent with grazing capaacity is an essential step in proper grazing management, but that alone may not achieve anticipated results. Total elimination of grazing would probably not achieve the rapid results desired-- sometimes demanded-- by some human expectations.

The big sagebrush desert vegetation presented here may have been a human-induced disturbance climax (ie. a man-made desert) or it might have been a climax sagebrush desert (ie. this was the potential natural vegetation). Either way, this range plant community was used as an example of (at least to to illustrate) the big sagebrush form of Great Basin Desert, Kuchler unit 32 (Great Basin Sagebrush).

The scarcity of herbaceous plants in this vegetation was emphasized. Squirreltail bottlebrush (Sitanion hystrix) was the most common (about the only) native perennial bunchgrass. Most of the herbaceous biomass was produced by cheatgrass or downy brome.There were scattered and still small (four to six inches in height) plants of Russian thistle or tumbleweed (Salsola kali var. tenuifolia= S. iberica= S. pestifer). Reason(s) for small size of tumbleweed at this relatively late season (early summer) was unknown. It is tough country when even the tumbleweed are stunted!

Typical physiognomy and community structure of big sagebrush desert scrub. This range vegetation should be compared to that of the big sagebrush steppe shown immediately above. Note again that the big sagebrush steppe range shown above was itself transitional between more typical sagebrush steppe with greater grass undertstorey and sagebrush desert scrub like that shown here that was without any (or with only an extremely sparse) herbaceous layer. The range plant community featured here (and the one shown immediately below) was a shrubland in contrast to the grass-shrub savanna of even the transitional big sagebrush steppe.

Vale District, Bureau of Land Management, Malheur County, Oregon. June. Estival aspect (but there is little difference in seasonal aspects in rang plant communities composed of nothing other than sagebrush). FRES No. 29 (Sagebrush Shrubland Ecosystem). K-32 (Great Basin Sagebrush). "Pure" shrub variant of SRM 403 (Wyoming Big Sagebrush). Sagebrush Series of Brown et aol. (1998). Retrogressive (degraded) state of basin big sagebrush/bluebunch wheatgrass association of Kagan et al. (2004) becuse there is not-- even though there should be-- a Wyoming big sagebrush/bluebunch wheatgrass association for Oregon as there is for neighboring Nevada. Artemisia tridentata ssp. wyomingensis/Pseudoroegneria spicata (= Agropyron spicatum) Shrubland (Nevada Natural Heritage Program, 2003).

 

62. Big Sagebrush desert range - The basin big sagebrush-dominated range vegetation shown here was on land transitional between Owyhee Upland and Basin and Range provinces (Franklin and Dyrness, 1973, ps. 6, 34-38). [Further details in regards to landscape were given in the immediately preceding caption.] This range was in close proximity to that in the two immediately preceding photographs. All statements made regarding physiographic details of that range applied equally to this range. Most descriptions of the preceding range plant community applied with equal valididty to this range plant community except that this range site had an edaphic environment more mesic and generally less extreme for plant growth than that of the preceding range site.

The major differneces were in subspecies of the dominant plant (basin big sagebrush vs. Wyoming big sagebrush) and in the presence of more herbaceous plants. Herbaceous species were so "few and far between" that ascribing an herbaceous layer or understorey to this vegetation would be unwarrented, but there were more grasses present here on the more mesic range site. The major (perhaps the only real) difference was presence of more squirreltail bottlebrush on this range site dominated by basin big sagebrush than on the preceding range site dominated by Wyoming big sagebrush shown in the preceding two slides.

Cheatgrass and Russian thistle or tumbleweed were more abundant and individual plants were larger on this basin big sagebrush-dominated range. Differences were more pronounced for cheatgrass, but this Eurasaia annual invader was still more limited than the perennial squirreltail bottlebrush. A high proportion of the squirreltail bottlebrush on this more mesic site grew under the crowns of basin big sagebrush (center foreground). This raised the possibility that some of the difference in cover of squirreltail between this and the preceding Wyoming big sagebrush range was due to previous grazing management (perhaps differences in degree, season, or distrubution of grazing use) as well as (maybe instead of) differences in range site like edaphic features.

The concept of disturbance climax, particularily a grazing disclimax (= one form of a zootic climax), was discussed in the preceding caption. The crowns of big sagebrush (as with the canopy of any shrub) affords some degree of protection to understorey species whether it be from scorching sun light, hail, wind, or grazing animals. In their discussion of zootic climaxes among sagebrush-dominated communities Franklin and Dyrness (1973, p. 233) cited a previous conclusion that sagebrush provides protection to perennial grasses which "may be the key reason why as much grass remains today as does occur on depleted rangelands". There were examples squirreltail bottlebrush growing beneath basin big sagebrush crowns, and even adjacent to shoot bases as shown in this slide, but there were also suirrreltail plants growing midway between big sagebrush plants so as to be fully exposed and vulnerable to any of the defoliating agents listed above.

In the description of the transitional big sagebrush-mixed bunchgrass introduced earlier, attention was directed to the conclusion of Young et al. in Barbour and Major (1995, p. 793) that on sagebrush steppe there were close synecological relations between big sagebrush and bluebunch wheatgrass. Franklin and Dyrness (1973, p. 233) reprinted previously listed reasons for retaining some sagebrush on sagebrush steppe ranges.

Whatever ecological relations and interactions may exist among grasses and sagebrush, the natural vegetation varies from bunchgrass grasslands with few or no shrubs to shrublands with little or no grass (naturalized annual or native perennial) or herbaceous layer(s) to the savanna of the ecotonal sagebrush steppe. Big sagebrush scrubland with little grass (any herbaceous species) was illustrated here.

Vale District, Bureau of Land Management, Malheur County, Oregon. June. Estival aspect. FRES No. 29 (Sagebrush Shrubland Ecosystem). k-32 (Great Basin Sagebrush). Scrub variant of SRM 401 (Basin Big Sagebrush). Sagebrush Series of Brown et al. (1998). Deteriorated (retrogressive) state of basin big sagebrush/bluebunch wheatgrass association of Kagan et al. (2004) because there is not-- even though there should be-- a Wyoming big sagebrush/ bluebunch wheatgrass association for Oregon as for neighboring Nevada. Artemisia tridentata ssp. wyomingensis/ Pseudoroegneria spicata (= Agropyron spicatum) Shrubland (Nevada Natural Heritage Program, 2003).

 
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63. Basin big sagebrush-green rabbitbrush disturbance climax- An example of a severely depleted or degraded (see definitions in the immediately succeeding caption)-- big sagebrush-dominated disclimax range served as an example of the sagebrush form of the Great Basin Desert, Kuchler unit 32 (Great Basin Sagebrush). Severe disturbance converted this range plant community, the potential natural vegetation of which was the Artemisia tridentata-Chrysothamnus viscidiflorus/native bunchgrass association (Franklin and Dyrness, 1973, p. 242), into this big sagebrush-green rabbitbrush shrub disclimax with basin big sagebrush as the dominant and green rabbitbrush as associate.

The only perennial bunchgrass species were widely spaced individuals of Sandberg bluegrass and squirreltail bottlebrush. The sparse cover and density of perennial grasses, which was conspicuously lower than that of other range plant communities shown in this series of slides, was graphically meaningful given the high production potential of this lowland habitat. Cheatgrass or downy brome, the naturalized Eurasian annual grass often dominant on depleted sagebrush steppe, was present at relative abundance (cover and density compared to all grasses) less than that of the native perennials. Most cheatgrass had reached seed-set stage (mostly at hard dough; just below hard seed stage) with some green leaves still present. At this phenological stage downy brome was "conspicuous by its absence".

Cause of range retrogression was unknown, but grazing abuse had to be considered as a likely major contibuting cause. Overgrazing was a logical suspect given the rich history and central economic importance of the range livestock in this vicinity (Brimlow, 1951). Most of this land was Public Domain used as open range until coming of the Taylor Grazing Act in 1934, and final adjudication of range allotments extended well into the 1950s. Under open range ranching much of this rangeland was, of necessity, purposely overgrazed. When the grass was free on unregulated public range each stockman was forced to continually overuse his patch of pasture to disuade "claim jumpers". Any unused forage was an open invitation to other graziers to move in with their herds and flocks and use free feed before somebody else beat them to it. Degraded range like that shown here is the legacy of Garrett Hardin's "Tragedy of the Commons" (Hardin, 1968).

Sometimes range in this degraded state (beyond doubt in Poor range condition class) is former farm ground. In this instance there was no physical evidence (eg. old back furrows or ditches) that this was an old field. There was no question as to sagebrush steppe having been the potential natural vegetation of this range site because rangeland adjacent to and in this same vicinity was climax big sagebrush-bluebunch wheatgrass steppe. An example of such relict pristine vegetaion-- and on a less mesic, less fertile range site-- was presented in the section devoted to sagebrush shrub-steppe range.

Sagebrush steppe range depleted or degraded (see definitions in caption immediately below) to this stage of retrogression has become from a sagebrush desert. Such range degradation exemplified a form of type conversion even though the vegetational change was unintentional. This change in successional state-- most probably a change in ecological potential-- of this sere (this seral stage) is likely to remain for the foreseeable future in human time scale. The inevitability of the return of climax in the grand scheme of the Clementsian model required millennia in semiarid and arid environments.

Artificial (= anthropogenic) conversion of sagebrush steppe to sagebrush desert as shown here served as an example of desertification. The Society for Range Management (Jacoby, 1989) provided the following definition of desertification: "The process by which an area or region becomes more arid through loss of soil and vegetative cover. The process is often accelerated by excessive continuous overstocking and drought." The Society of American Foresters (Helms, 1998) defined desertification as: "The progressive destruction ordegradation of vegetative cover, especially in arid or semiarid regions bordering existing deserts- note overgrazing of rangelands, large-scale cutting of forests and woodlands, drought, and burning of excessive areas all contribute to desertification."

For practical purposes the range vegetation of this and the next slide served as examples of Great Basin Desert. These disclimaxes or zootic climaxes were "islands" of the big sagebrush shrubland type (= big sagebrush scrub) found in Great Basin. This vegetation was on rangeland that was transitational between the Owyhee Upland and Basin and Range provinces (Franklin and Dyrness, 1973, ps. 6, 34-38) and at this state od degradation was an "island" or "outlier" sagebrush desert scrub of the Great Basin.

Burns District, Bureau of Land Management, Harney County, Oregon.June. Estival aspect. FRES No. 29 (Sagebrush Shrubland Ecosystem). K-32 (Great Basin Sagebrush). Shrub variant of SRM 401 (Basin Big Sagebrush). Sagebrush Series of Brown et al (1998). There was no appropriate association for this disclimax range shrubland community given in the Classification of Native Vegetation of Oregon (Kagan et al. 2004). The closest unit by the Oregon classification would be a retrogressive (degraded) form of basin big sagebrush/bluebunch wheatgrass association (Kagan et al. (2004) and this was wrong because the co-dominant green rabbitbrush was not included in the association title and dominance was more nearly that of Sandberg bluegrass. The Kagan et al. (2004) association was inconsistent with the earlier recognition of the Artemisia tridentata-Chrysothamnus viscidiflorus/native bunchgrass association by Franklin and Dyrness (1973, p. 242). This range vegetation was the Artemisia tridentata/Chrysothamnus viscidiflorus/Poa secunda Shrubland (Nevada Natural Heritage Program, 2003).

 
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64. Disclimax basin big sagebrush-green rabbitbrush desert- Rangeland having the Artemisia tridentata-Chrysothamnus viscidiflorus-perennial bunchgrass association as its potential natural vegetation (= climax plant community) had been degraded -- most likely through overgrazing compounded by drought (and perhaps by other human disturbances)-- into this disturbance climax (= zootic or anthropogenic climax) of the native composite shrubs with the native cespitose grasses eliminated. Sagebrush steppe range had been converted into sagebrush desert range.

[Rationale for the conclusion that this range vegetation was a grazing disclimax was presented in the immediately preceding caption.]

The set of processes called desertification (Jacoby, 1989; Helms, 1998) had resulted in the artificial conversion (Clements, 1916, p. 157) of sagebrush-rabbitbrush shrub-steppe into the sagebrush-rabbitbrush shrubland (ie. savanna-grassland into desert). The most probable major factor in this example of retrogresssion was overgrazing, "continued overuse creating a deteriorated range" (Kothmann, 1974) or, though a much less precise definition, "continued heavy grazing which exceeds the recovery cpacity of the community and creates a deteriorated range" (Jacoby, 1989; Bedell, 1998).

Retrogression and regression were first defined by the Society for Range Management as being synonymous with range degeneration, "the process whereby the same area becomes succsssively occupied by different plant communities of lower ecological order" (Kothmann, 1974). In later definitions the Society for Range Management still used range retrogression as a synonym for range degeneration but redefined range retrogression as "the degradation of a site caused by biotic or abiotic factors which results in movement of the site to a lower successional status within the same ecological potential" and offered, as a term new to the SRM Glossary, range degradation which was defined as "the degeneration of a site caused by biotic or abiotic factors which results in a lowered successional stauts to the point that ecological potential is changed" (Jacoby, 1989).

Obviously these definitions were messed up! "Degeneration" is "degradation" and "degradation" is "degeneration" so that these two terms have to be synonyms, but "range degradation" is "degeneration" "...to the point that ecological potential is changed" whereas "range degeneration" (as a synonym for range retrogression) is "degradation" but still "... within the ecological potential" and yet "degradation" was defined as more severe than "degeneration". Go figure!

It was remarked in the preceding caption that in human time scale the site potential of range at this state of range retrogression, degeneration, degradation (take your choice of these terms) has been reduced or lowered (moved to a lower successional stage at which it will remain for indefinite time, perhaps for centuries). This was the original meaning of disclimax (Clements, 1936, Weaver and Clements, 1938, ps. 86, 88). Incidentially, Clements (1916, ps. 145-149 passim) traced the term retrogression to its use by Henry Chandler Cowles who was one of the first ecologists (if not the first one), to describe development of vegetation, including regression (= retrogression) as the backward (retrograde) change in a sere or on a site.

This desertified former sagebrush steppe that was lowered in ecological potential to sagebrush desert became a human-induced (= man-made) "island" of the Great Basin Desert. This rangeland was on a transition landscape between the Owyhee Upland and Basin and Range provinces (Franklin and Dyrness, 1973, ps. 6, 34-38). Range plant species more common and in greater relative abundance in the Basin and Range province had migrated into an adjoining landscape as species of higher ecological (successional) order on the latter rangeland had decreased in abundance due to disturbances like overgrazing and recurrent drought. The range plant community that developed and stabilized on the deteriorated range habitat, the degraded range site, was a sagebrush desert disclimax. This range retrogression was desertification. Great Basin Desert expanded as floristic "frontier outposts" in response to mismanagement of range resources coupled with natural disturbances.

Burns District, Bureau of Land Management, Harney County, Oregon. June. Estival aspect. FRES No. 29 (Sagebrush Shrubland Ecosystem). K-32 (Great Basin Sagebrush). Shrub variant of SRM 401 (Basin Big Sagebrush). Sagebrush Series of Brown et al. (1998). There was no appropriate designation for this big sagebrush-green rabbitbrush/ native bunchgrass range community in the Classification of Native Vegetation of Oregon (Kagan et al., 2004). Degraded form of basin big sagebrush/bluebunch wheatgrass association of Kagan et al. (2004) did not include green rabbitgrush which was the true co-dominant species or Sandberg bluegrass which was more common than bluebunch wheatgrass. Proper designation was Artemisia tridentata/Chrysothamnus viscidiflorus-Poa secunda Shrubland (Nevada Natural Heritage Program, 2003).

 

65. Companions of the cold desert- Basin big sagebrush (Artemisia tridentata subsp. tridentata), left, and green rabbitbrush (Cyrysothamnus viscidiflorus), right, were dominant and associate species, respectively, on a disclimax Great Basin-like desert. These two individual shrubs were those in center midground of the preceding slide of a former big sagbebrush-dominated bunchgrass steppe that had become desertified, probably by overgrazing exacerberated by droughts in the 1930s, 1950s, and 1990s. Rangeland in the immediate vicinity of this degraded range-- and with less mesic, less fertile range sites--had pristine plant communities of climax big sagebrush steppe. (One such relict area that was in a management unit adjacaent to this degraded range was presented as the first example of sagebrush shrub-steppe in that section of this publication.)

These two composite shrubs are intimately associated with each other across much of the vast Intermountain Region. Students were referred to the numerous publications of the Shrub Research Consortium (published under auspices of U.S. Forest Service) dealing with the Artemisia and Chrysothamnus species and the various sagebrush-dominated communities. The third proceedings (McArthur and Welch, 1986) would be a good one to begin with.

Burns District, Bureau of Land Management, Harney County, Oregon. June. Estival aspect. Phenological stage: full-bloom for green rabbitbrush.

 
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66. Basin big sagebrush-spiny hopsage scrubland range- This example of the Artemisia tridentata-Grayia spinosa (= Atriplex spinosa) association (Franklin and Dyrness, 1973, p. 242) had developed on land transitional between the Owyhee Upland and the Basin and Range provinces. This range vegetation was in conterminous with the three big sagebrush-dominated range plant communities just before the last range plant community of basin big sagebrush-green sagebrush desert scrub (the six photographs just before the three immediately preceding this photograph). The range vegetation shown here was clearly shrubland with herbaceous plants limited to squirreltail bottlebrush and cheatgrass. These grasses were present only in trace amounts. Forbs (including Eurasian annual cricifers) were not present. The Compositae was represented by the dominant shrub and by spiny horsebrush (Tetradymia spinosa) which was the third most abundant plant species after the associate spiny hopsage.

Franklin and Dyrness (1973, p. 245) briefly described this and similar range vegetation as desert or salt desert shrub communities. Young et al. in Barbour and Major (1995, p. 792) discussed such range shrub vegetation only in context of pluvial basin communities. These latter workers concluded: "Grayia spinosa is one of the few species with sufficient ecological amplitude to occur in both Aretmisia- and Atriplex-dominated communities".

This upland habitat was not a saline site or alkali site in the strict sense. Presence of the high "ecological amplitude" spiny hopsage as associate to Wyoming big sagebrush

Vale District, Bureau of Land Management, Malheur County, Oregon. June. Estival aspect. FRES No. 29 (Sagebrush Shrubland Ecosystem). K-32 (Great Basin Sagebrush). Scrub variant of SRM 403 (Wyoming Big Sagebrush). Sagebrush Series of Brown et al. (1998). There was no big sagebrush-spiny hopsage association in the Classification of Native Vegetation of Oregon (Kagan et al. 2004), but there was for Nevada: Artemisia ssp. tridentata-Grayia spinosa Shrubland (Nevada Natural Heritage Program, 2003).

 

67. Shadscale (Atriplex confertifolia) range- Plants were sparse and the plant community was far from scenic but this range vegetation was a good example of a salt desert shrub community (Franklin and Dyrness, 1973, p. 245), specifically the Atriplex confertifolia community (Young et al. in Barbour and Major, 1995, p. 788). These latter author indicated that though shadscale communities have been referred to as "salt deserts", adaptation of shadscale may be more to drought than to salinity. Many soils on which shadscale range has developed in Nevada and northern California are in reality low in soluble salts, but precipitation is certainly always scarce and thus soil moisture limiting (Young et al. in Barbour and Major, 1995, p. 788).

Although it might seem to be "slim pickin's" to human senses, sheep, goats, and native ruminants find shadscale range to be attractive to their senses. Shadscale provides palatable browse-- limited as it typically is-- and this species has proved to be tolerant of reasonably heavy defoliation.

Most of the shrubs in this view (incuding those with brown, dead leaves) were shadscale. Grasses were limited with the most common species being cheatgrass. This was unusual (in fact, unique) because all other range types in this general area (including several associations of big sagebrush and low sagebrush shrub-steppe and big sagebrush-spiny hopsage shrubland as well as big sagebrush shrub-steppe degraded to big sagebrush desert) supported cheatgrass is substantially lower proportions than that of whatever native perennial bunchgrass was dominant. Russian thistle was also present (and also in small quantities).

Vale District, Bureau of Land Management, Malheur County, Oregon. June. FRES No. 30 (Desert Shrub Shrubland Ecosystem). K-34 (Saltbush-Greasewood). SRM 414 (Salt Desert Shrub). Shadscale Series of Brown et al. (1998). Understorey largely lacking so no apparent appropriate vegetation unit in Classification of Native Vegetation of Oregon (Kagan et al. 2004). Closest given for Oregon was the shadscale/bottlebrush squirreltail association of Kagan et al. (2004). Instead the more descriptive unit was Atriplex confertifolia Great Basin Shrubland (Nevada Natural Heritage Program, 2003).

 

68. Shadscale range on which big sagebrush was the associate species- Range vegetation viewed here differed from that in the preceding "quadrant" in presence of Wyoming big sagebrush as an associate to the dominant shadscale or spiny saltbush. Grass cover and density was somewhat more limited than in the preceding sample of shadescale range but again cheatgrass was the dominant (almost the only) grass species. Russian thistle was also present but not common.

Traditionally shadscale-dominated range vegetation was grouped with range commuities dominated by such species as black greasewood and bud sagebrush (Artemisis spinescens) as salt desert shrubland or salt desert scrub. This general conglomerate of range types (a "super type") was once used largely as winter range, especially for for sheep. It was always valuable for native ruminants like pronghorn (Antilocarpra americana) and mujle deer (Odocoileus homionus) .

Vale District, Bureau of Land Management, Malheur County, Oregon. June. FRES No.30 (Desert Shrub Shrubland Ecosystem). K-34 (Saltbush-Greasewood). SRM 414 (Salt Desert Shrub). Shadscale Series of Brown et al. (1998). Understorey lacking and limited mostly to cheatgrass so the closest vegetation unit listed for Oregon was the shadscale/ bottlebrush squirreltail association (Kagan et al., 2004) and that was not "it". Instead the present vegetation was probably climax and the Atriplex confertifolia Great Basin Shrubland designated for Nevada (Nevada Natural Heritage Program, 2003).

 

69. Shadscale or spiny saltbush (Atriplex confertifolia)- Whole plant of shadscale. This specimen was the plant in center foreground of preceding slide. For discussion of spiny saltbush as a valuable browse plant students were referred to Dayton (1931, ps. 30-31), Forest Service (1940, B28), and Sampson and Jespersen (1963, ps. 65-66). It was revealing (and perhaps somewhat nostalgic) that the most recent treatments-- brief though they were-- of native shrubs as valuable browse species date back 40 to 70 years.

Vale District, Bureau of Land Management, Malheur County, Oregon. June.

 

70. Shadscale or spiny saltbush (Atriplex confertifolia)- Shoots or leaders of shadscale with two views showing detail of leaves and stems.

Vale District, Bureau of Land Management, Malheur County, Oregon. June.

 
Miscellaneous Shrublands Affilitated with Great Basin Desert
 
71. Profile of an alluvial soil supporting basin big sagebrush (Artemesia tridentata) illustrating that certain range plants can indicate the potential of soil or other factors for crop production. FRES No. 29 (Sagebrush Ecosystem). Another of several variants of K- 32 (Great Basin Sagebrush). SRM 401 (Basin Big Sagebrush). Sagebrush Series of Brown et al. (1998).
 

The vast Intermountain Region is generally regarded as the land area between the Rocky Mountains and the Cascade and Sierra Ranges, including the Great Basin portion of the Basin and Range province, the Colorado Plateau, and perhaps the Wyoming Basin it being a landscape that interrupts the Rocky Mountain System. Within this immense part of the continent there is vegetation ranging from grasslands, shrub-steppe (a semiarid shrub savanna), deserts (= desert scrub or desert shrublands), mountain brush ("soft chaparral"), foothill woodlands like the juniper-pinyon type, and, depending on interpretation, quaking aspen communities to coniferous forest edges.

Precise categorization of vegetation (thus range vegetation types) would be impossible and would vary among individuals having different backgrounds, professional perspectives, values, and other biases or indoctrinations. The present author interpreted most of this geographic region as having shrubland as the major general climax but with occasional sizable acreages of grassland, shrub-grass savanna, and tree-grass savanna. The Great Basin Desert is, as are all deserts, primarily an arid shrubland but with some trees along with grasses, forbs, etc. Finally, it should be born in mind that two to several of these expressions of vegetation frequently exist side-by-side and with tremendous variation in basic form of vegetation even within one range or other management unit. Several examples of the latter phenomenon and the general mosaic of vegetation were presented below.

The next three photographs were taken on the same fenced range (within the same fence) and the three examples of vegetation were conterminous. All pictures were taken within a few minutes of each other. Any units of vegetation can be seen as artificial and existing in the eye and imagination of the ecologist and/or photographer, but in this current case each range plant community or arbitrary unit of vegetation was clearly distinct and unique from the other two. In the interpretation of this author-photographer the vegetation existed as a patchwork on the range and it was an example of patch dynamics with each of the three range communities being a successional stage on the same sere. The vegetation was in the southwestern corner of the Wyoming Basin, east of the Wasatch Range and north of the Unita Mountains.

 

72. Intermountain grassland- This first photograph was of a shortgrass-dominated grassland. The dominant species was galleta. Blue grama was the associate species with western wheatgrass and needle-and-thread appearing to comprise the bulk of the remaining cover and biomass. There were a few widely scattered shrubs of spiny hopsage (Grayia spinosa= Atriplex spinosa), but these were not dense enough to present even the suggestion of a shrub savanna. This was a consociation of galleta. There were no forbs. There was a trace of cheatgrass or downy brome, but it was "real scarce".

Unita County, Utah. June. FRES No. 40 (Desert Grassland Ecosystem). Mapped as K-49 (Sagebrush-Wheatgrass Steppe), but at scale finner than Kuchler mapping unit it was K-47 (Grama-Galleta Steppe). K-47 at Kuchler scale occurred farther south where location and description of vegetation best fit SRM 502 (Grama-Galleta) of Southwestern Cover Types. This vegetation was interpreted as an outlier of K-47.

 

73. Intermountain shrub-steppe- The second photograph was of a shortgrass-dominated community with galleta still clearly the dominant grass, but cover and density of spiny hopsage had so increased that the vegetation had the appearance of a spiny hopsage-galleta savanna. There were also a few widely scattered plants of spiny horsebrush (Tetradymia spinosa). Blue grama was still the apparent associate species and western wheatgrass and needle-and-thread were common. There were no forbs and apparent cover of cheatgrass was scarace as in the first example of vegetation. The main difference was addition of the shrub component, a difference of two native species.

Unita County, Utah. June. FRES No. 40 (Desert Grassland Ecosystem). As indicated for the preceding slide, Kuchler potential natural vegetation was interpreted to be an outlying unit (an "island") of K-47 (Grama-Galleta Steppe), but the presence of spiny hopsage made the vegetation shown in this slide more closely fit a described variant of SRM 414 (Salt Desert Shrub) in which spiny hopsage was viewed as representing a transition to sagebrush desert, one (or more) of the sagebrush cover types for the Great Basin Region (Shiflet, 1994). Again, the vegetation shown in this photograph was aptly described as a spiny hopsage-galleta savanna. Variant of Mixed Scrub Series of Brown et al. (1998).

 

74. Tansy mustard-cheatgrass weed patch- Deterioration of the range plant communty (or of the two range communities) presented immediately above resulted in the depleted range shown here. Deterioration (obviously to Poor range condition class) resulted as the vegetation digressed down the sere to a successionally lower seral stage that was dominated by two invader species (two naturalized Eurasian annuals). This is the retrograde direction (from or versus succession) in vegetation dynamics known as retrogression.

These three photographs illustrated the mosaic of vegetation in various states of succession/retrogression that can be explained by the current theory of patch dynamics. The stage of retrogression seen in the third slide was so severe-- so far down the sere-- that no FRES number, Kuchler unit, or SRM cover type was possible. (Who would want to claim it?) Unita County, Utah. June.

 

75. Spiny hopsage (Grayia spinosa)- Branches and leaves of spiny hopsage. Unita County, Utah. June.
 
76. Inflorescences of spiny hopsage- There is some dispute as to whether Grayia or Atriplex is the more nearly correct genus to apply to this plant according to the rules of nomenclature. There is no dispute that it is a halophytic species in the Chenopodiaceae, one of the major families of range shrubs throughout the Intermountain Region. Unita County, Utah. June.
 

77. Spiny (or shortspine) horsebrush (Tetradymia spinosa)- This member of the Compositae is often regarded merely as brush (a noxious woody plant), but Dayton (1931, p. 177) reported that other investigators found it to be a valuable component of diets in sheep and pronghorn in the Red Desert. He also reported that another common name for this shrub was cotton thorn, a descriptive designation as can be seen from this close-up view of the stemy branches and "fluffy" inflorescences. Unita County, Utah. June.

The greater Intermountain Region was generally interpreted by Garrison et. al. (1977) as FRES No. 29 (Sagebrush Shrubland Ecosystem) plus some elements of FRES No. 30 (Desert Shrub Ecosystem), especially K-34 (Saltbush-Greasewood). The concept of a vegetational mosaic in this region (with special reference to Wyoming) was explained in some detail by Knight (1994, ps. 110-119) for what he labeled as the Desert Shrubland Mosaic. Knight (1994) divided the Wyoming desert shrublands into: 1) saltbush desert shrubland, 2) mixed desert shrubland, 3) greasewood desert shrubland, 4) saltgrass meadow, and 5) basin grasslands. These (the Desert Shrubland Mosaic or general Desert Shrubland Ecosystem) were distinct from the Sagebrush Steppe, though of course all of these formed a quilt-work with each other as well as having patch-works within themselves. Such is the nature of vegetation, especially with extremely varied soils and topography:

"The vegetation mosaic of Wyoming deserts is strongly influenced by water availability and topography. Greasewood desert shrubland and saltgrass meadow are characteristic of playas and other comparatively wet depressions. On the upland, the mosaic is composed of mixed desert shrubland, saltbush desert shrubland, and desert grasslands. Shrublands dominated by big sagebrush are intermingled with desert shrublands and grasslands, commonly occurring where soils are less saline, where drainage is not impeded by fine-textured soils, and on the lee sides of slopes where snowdrifting is greater. Extensive sagebrush steppes ... are found at slightly higher elevations or where annual precipitation is somewhat greater" (Knight, 1994, p. 110).

 

78. Saltbush desert shrubland or salt desert shrub- Gardner or Nuttall saltbush or, sometimes, saltsage (Atriplex gardneri) was the dominant of this sparse range community, but bud sagebrush or bud-sage (Artemesia spinescens) was a strong associate species becoming a local co-dominant. Forbs were scarce but there were widely scattered plants of Hooker sandwort (Arenaria hookeri) and squarestem phlox (Phlox muscoides). (For that matter, everything was widely scattered.) Grasses were absent. As is the case for most of the Atriplex species Gardner saltbush is an important browse plant for both livestock, especially sheep, and big game species. Bud-sage is also a valuable browse species though of lower palatability. The major grazing animal on this desert range was the white-tail prairie dog (Cynomys leucurus) that had built a scattered-- widely-- town across this bleak-looking landscape.

This range vegetation was definitely not in the Great Basin or even Basin and Range physiographic province (it is part of the Colorado Plateau physiographic province). The range plant community certainly was desertscrub and could conveniently be thought of and treated as an "island of Gret Basin Desert vegetation.

Great Divide Basin, a section of the Wyoming Basin. It was not apparent from the gray color of this shale-derived soil, but this general area was in or on the edge of what is known as the Red Desert (Fenneman, 1931, ps. 143-144). Sweetwater County, Wyoming. July. FRES No. 30 (Desert Shrub Ecosystem). K-34 (Saltbush-Greasewood). One of several variants of SRM 414 (Salt Desert Shrub). Variant of Saltbush Series of Brown et al. (1998).

 
79. View of Wyoming badlands- This escarpment rising above the saltbush-bud sagebrush scrub shown in the preceding slide was derived from shales and sandstones of the late Cretaeceous period (Knight, 1994, p. 116) and showed the parent material of the soil shown in the slide immediately above. This is one of several badlands in northcentral and western North America. Sweetwater County, Wyoming. July. FRES No. 30 (Desert Shrub Ecosystem). K-34 (Saltbush-Greasewood). One of the variants of SRM 414 (Salt Desert Shrub). Saltbush Series of Brown et al. (1998).
 

80. Bud sagebrush, bud sagewort, or simply bud-sage or budsage (Artemesia spinescens)- This species of sagebrush differs from other members of Artemesia in having clustered inflorescences superficially resembling a bud. It is a valuable browse plant for sheep and quite drought-resistant (Dayton, 1931, p. 172), but it may be toxic to cattle at certain levels (Kingsbury, 1964, p. 393).

Consociations of budsage like the one shown here are much less common than those of shadscale, greasewood, and winterfat.

Landers County, Nevada. March. Budsage was listed by the Society for Range Management (Shiflet, 1994) as one of several variants of a general Other Sagebrush Types (SRM 408, Other Sagebrush Types). It would most likely fall under FRES No. 29 (Sagebrush Shrubland Ecosystem). K-32 (Great Basin Sagebrush). Variant of Sagebrush Series of Brown et al. (1998).

 
 

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