Oak-Hickory Forests-II

The fundamental and practical distinction between coniferous and deciduous forests is useful (and was used herein), but precise, non-arbitrary "lines" are impossible when presenting and discussing forest range types in the eastern half of the continent. This is especially the case when climax or potential natural vegetation is used as the basis for forest types (ie. when cover types, or the more specific management cover types, are discussed as being more or less synonymous with permanent forest types). As discussed in detail below, the epic work of Lucy Braun (1950) is still the definitive basis for the ecological discussion and classification of those North American forests which extend from the Atlantic Coast to slightly beyond the Missouri and Mississippi River drainages. Braun (1950) included all the coniferous forests (forest types, regions, etc.)-- the generic "southeastern pine region"--as part of her one Deciduous Forest Formation. 

The forest range types included in the following section include coniferous, deciduous, and mixed coniferous-deciduous forests. This is confusing but unavoidable given the nature of the vegetation and the standard understanding (the Braun interpretation) of ecological relations and classification of  this forest vegetation. Most of the southeastern pine types presented are management cover types maintained silviculturally as more economically valuable coniferous forests rather than as the climax mixed hardwood-pine forest types. In other words, efforts were made to fit the Society of American Foresters (1980) cover types with the climax types of Braun (1950) and the potential natural vegetation units of Kuchler (1966).      

The major forest communities or forest zones of eastern North America are broad or wide in their spatial patterns unlike the narrow zonation characteristic of the forests of western North America. The “young” mountains of the western part of the continent are taller (in fact, still getting taller) and as a result have more elevation-based zonation of vegetation than do the geologically older and more eroded (lower) eastern mountains such as the Applachians or Ozarks. So too, are the soils of the Atlantic Coast more zonal (ie. major soil units are larger or broader in spational dimension like those of the vast continental interior whereas soils of the Rocky Mountains and the Pacific Slope ranges are more of the intrazonal spatial scale. See for illustration the national soil map of dominant soil orders and suborders (Soil Survey Staff, 1998).

 Vankat (1979, p. 137) wrote that relief within the eastern deciduous forest “is quite variable” yet earlier Vankat (1979, p. 41) had also correctly noted that “low hills “ were characteristic of much of this deciduous forest region. Again, contrast this with the extreme physiography of the Rockys or Sierra Nevada-Cascade Ranges.

Braun (1950, ps. 35-37) listed nine forest regions making up the Deciduous Forest Formation of eastern North America:

                1. Mixed Mesophytic Forest Region,

                2. Western Mesophytic Forest Region,

                3. Oak-Hickory Forest Region,

                4. Oak-Chestnut Forest Region,

                5. Oak Pine Forest Region,

                6. Southeastern Evergreen Forest Region,

                7. Beech-Maple Forest Region,

                8. Maple-Basswood Forest Region, and

                9. Eastern Hemlock-Eastern White Pine-Northern Hardwoods Region.

 Braun (1950, ps. 11-12) interpreted these same combinations of species as forest communities at the scale (both spatial, mostly, and, also, temporal) of climax association  from which, as quoted immediately above, Braun derived the names of forest regions. Braun (1950, ps. 11-12) distinguished between the association-abstract and the association-concrete, a distinction discussed in the review of the derivation of vegetation cover type from the concept of plant association. The Braun association is the association of F.E. Clements. Indeed the entire ecological paradigm on which Braun (1950, ps. 10-15) based her monographic treatment of the North American Deciduous Formation is Clementisan except allowance for and inclusion of edaphic and physiographic climaxes of Cowles, Tansley, etc.  Vankat (1979, ps. 137-150) and Delcourt and Delcourt in Barbour and Billings (2000, ps. 365-378) described eastern deciduous forest vegetation under the Braun (1950) associations of the Clementsian model.

It is important to bear in mind that the Braun associations can occur in more than the one forest region bearing the name of the association (eg. the Oak-Pine Association commonly occurs and the Maple-Basswood Association infrequently occurs in parts of the Oak-Hickory Forest Region).

Several of the species combinations that delineate deciduous forest regions and associations were also used as forest cover types by the Society of American Foresters (Eyre, 1980) as for example White Pine-Hemlock (SAF 22), White Pine-Northern Red Oak-Red Maple (SAF 20), Sugar Maple-Basswood (SAF 26), and Beech-Sugar Maple (SAF 60). The Society of American Foresters emphasized that it’s forest cover types were “based on existing tree cover” (… forest as they are today…”) and that some types may be climax while others are “transitory” (ie. seral stages leading to another climax).

Braun (1950, p. xiii) specified: “Some of the communities for which composition is given are readily referable to ‘forest cover types’ as defined by the Society of American Foresters”. She then added, “However, an attempt to classsify all communities as to ‘cover types’ would be artificial” and often impossible. Undoubtedly this was due to the differences in classification by Braun’s climax basis (with seral communities clearly specified) versus the existing or present-day forest communities basis of the SAF.

 The Society for Range Management (Shiflet, 1994, p. xi) also specified the criterion of “existing vegetation” and that some rangeland cover types are climax and others are seral. The author of this collection of photographs and descriptions repeatedly reminded readers of this situation, but specified that most of the rangeland and forest cover types included herein were climax vegetation. That criterion exist for forest range types of the Eastern Deciduous forest Formation with most photographs being of either old-growth or second-growth forest with climax species composition as described in the classic literature such as Braun (1950) or Shelford (1963, ps. 17-119).

The nine forest regions of Braun (1950, ps. 35-37) were retained with little modification as series in the fairly comprehensive system of vegetation (primarily, climax; secondly, disclimax or subclimax) used in A Classification of North American Biotic Communities by Brown et al. (1998). Their organization of the Eastern Deciduous Forest Formation was: Oak-Hickory Series, Oak-Chestnut series, Beech-Maple Series, Oak-Pine Series, Maple-Basswood Series, and Hemlock-White Pine-Mixed Hardwood Series within the Northeastern Deciduous Forest biotic community and Mixed Mesophytic Series and Pine Series within the Southeastern Deciduous and Evergreen Forest biotic community. The Brown et al. (1998) series were included below following SAF and/or SRM cover type designations.

Their like, their genre of comprehensive, panaramic, descriptive, first-hand accounts of vegetation on this grand scale, will not likely appear again before icicles hang in Hell. The contemporary research world is hung up on numbers, even generated or simulated (vs. real data) numbers often for numbers-sake alone, and especially numbers of publications. This has gone beyond Lord Kelvin’s admonition to “express it in numbers”,  (indeed Kelvin used actual numbers derived from physical experiments) to the point that quantity is everything and quality (always subsidary to quantity) itself is based on numbers. Not only is there little room for Descriptive Ecology, but there is hardly more for descriptive analysis of experiments and observations because the gold-standard of refereed publications has descended, has been perverted, to the quantitative entity of LPU (Lowest Publishable Unit). A natural length paper based on objectives of the study is split into as many LPUs as possible to extend the author’s bibliography. This procedure does not allow enough results to be included in any one paper to allow a discussion of  findings from a comprehensive perspective. Besides the experimental procedure (complete with lots of numbers and split-nine-ways-to-Sunday replications) is the most important part according to anonymous peer-reviewers.  

In an institutional culture where “Publish or Perish” has become prostituted to a realm of pot-boiler papers written from predictable-outcome, piss-ant projects the next generation of Brauns, Weavers, Shelfords are “dead meat” if they devote (ie. sacrifice) their careers to document for eternity the kind of knowledge their “takes a lifetime “ research produced. Such incredible work is left to not only the fully vested or tenured but the tenured full professor of independent financial means at career’s end (and then there is not enough time left to do the work). A key factor in the creative genius and amazing productivity of Frederic E.Clements was that he was able to spend most of his career working for the rich Carnegie Foundation which freed him from the routine of classroom teaching and daily chores of academia thereby enabling him the luxury of a self-proclaimed “escaped professor” (Brewer, 1988, p. 503).  Alternatively, the most lasting and useful research is the province of the academic martyr to whom pursuit of knowledge or satisfaction of curiosity are of higher utility than organizational rank and its financial renumeration.

 Thus the Ecology student is left with the classical works of those “giants in the earth” who reigned when knowledge was the domain of a more leisurely, honest, genteel, and collegial time and culture.

The scholar of biblical texts cannot read just the several English translations of the Holy Bible. He must also understand the native tongues of Hebrew, Arabic, or Greek in which Holy Writ was written. So too with the “scripture” of Ecology. And the language of vegetation, at least North American vegetation, is Clementsian. The serious student of vegetation must be knowledgable and conversant in this language given that so much of the all-encompassing vegetation literature was written predominately from the view of Clementsian Ecology (and vocabulary). These original, monographic works remain the basis, however distant, of current investigations or even classifications of vegetation. The basic ecological concepts in such natural resource fields as Range Management and Forestry remain Clementsian at root (eg. the Clementsian association is the basis of the forest and range cover types as used in North America).

Any who would refuse to familarize themselves with Clementsian Ecology because there are exceptions to and alternative models for some of its general, long temporal-large spatial scales traverse the terrain of ecological literature half blind. In their zeal to reform the basic vegetation paradigm to include, justifiably, the exceptions they end up “throwing the baby out with the bath water”.

Sugar maple-dominated forest in the Ozark Plateau constitute a more mesic phase(s) of the Oak-Hickory Forest Region (Braun, 168-170). Specifically, sugar maple-dominated forests in the Oak-Hickory Forest Region were maple climaxes (climax sugar maple-dominated forests) the same as (at least, equivalent to) the maple climaxes that define the Maple-Basswood Forest Region of Braun (1950, ps. 327-336). The quote from Braun (1950, p.34) cited in the introduction to this chapter bore reciting: "Each of the several climaxes, although characterizing a specific region, nevertheless occurs in other regions.”. Braun (1950,p. 164) also stated: "The forest of the most mesophytic slopes usually contain sugar maple and an admixture of other mesophytic species". In other words, sugar maple is a defining, dominant species of some upland, slope forest in the oak-hickory forests. Thus there were the climax sugar maple-dominated forests in the Ozark Plateau that were presented in this portion of the Oak-Hickory Forest chapter.

Three forest tracts dominated by sugar maple were described in this portion of Oak-Hickory Forests-II. These separate tracats of forest range were similar and comparable to published descriptions of sugar maple forests in the Ozark Highlands (Ozark Plateau). Two forms, phases, variants, (or whatever they would be designated) of climax sugar maple were recognized for the Ozark Mountains by forest ecologists. These were the Acer saccharum-Quercus alba associes of limestone slopes and the Acer saccaharum-Carya cordiformis associes" that Braun (1950, ps. 168-169) recognized from the preceding work of Steyermark (1940). Both Steyermark (1940) and Braun (1950) used the Clementsian monoclimax vegetation system (Clements, 1916) in which associes "is the developmental equivalent of the association" so "used where the community is not permanent" but seral (Weaver and Clements, 1939, p. 99). In the geologic time scale of monoclimax theory the limestone bluffs and hills of the Ozarks would be worn down to a peneplane so as to eventually become the regional climax (monoclimax) of oak-hickory forest. Forests of sugar maple (with co-dominant tree species) on more favorable, mesic sites (eg. north and east slopes) are in monoclimax theory, postclimax in oak-hickory regional (climax) forests. In the polyclimax theory of Tansley or climax pattern theory of Whittaker the Clementsian associes of Steyermark (1940) would be associations.

The Acer saccharum-Quercus alba associes and Acer saccaharum-Carya cordiformis associes would be interpreted as variants of the Society of American Foresters (Eyre, 1980, p. 30) forest cover type, Sugar Maple (SAF 27). The forest cover type description of SAF 27 in Eyre (1980, p. 30) included four subtypes, two of which corresponded to the two forms of the moist slope Ozark Highlands forest: the sugar maple-bitternut hickory "restricted to deep soils in the southernmost part of Quebec" and the sugar maple-basswood-white ash subtype "found in the lowlands of the St. Lawrence Valley." Obviously authors of the sugar maple cover type description were unaware that the same subtypes (the associes of Steyermark [1940]) also existed in the Ozark Mountains of Missouri.

This sugar maple-dominated forest range type (three variants or forms) was described as mesic-limestone forest by the system of classification and designation in Nelson (1987, p. 28; 2005, ps. 122-125). Two of these variants of the sugar maple cover type had developed on limestone bluffs along (above) Modoc Creek and one was on a steep north slope (limestone parent material though not near a stream) at the western boundary of the Springfield Plateau of the Ozark Highlands. These were presented and described below as sugar maple-bitternut hickory (north slope), sugar maple-white ash- northern red oak (east slope), and sugar maple-northern red oak (north slope).

1. Postclimax of the Oak-Hickory Forest Region- A mesic, north slope of limestone bluffs above Modoc Creek supported a sugar maple-bitternut hickory (Acer saccaharum-Carya cordiformis) forest that was--when viewed from the Clementsian perspective--postclimax for oak-hickory (hardwood, in general) forests of the Ozark Highlands. On this limestone bluff forest sugar maple was the tree species with most regeneration, but this was followed closely by bitternut hickory. Associated tree species were (in this general order) white ash (Fraxinus americana), basswood or American linden (Tilia americana), hackberry or, sometimes, western hackberry (Celtis occidentalis), northern red oak (Quercus rubra= Q. borealis var. rubra), chinquapin (=chinkapin) oak (Q. muehlenbergii), black walnut (Juglans nigra), slippery or red elm (Ulmus rubra), honey locust (Gleditsia triacanthos), Kentucky coffeetree (Gymnocladus dioicus), and sycamore (Platanus occidentalis) .

There were two shrub zones: 1) upper (higher on bluffs; farther from creek) and 2) lower (farther down on bluffs; next to creek). The higher or upper zone had one major shrub layer that was dominated by eastern dogwood (Cornus florida) with eastern redbud (Cercis canadensis) as the associate shrub. The lower zone on bluffs had two major or prominent shrub layers or strata: 1) taller shrub stratum made up almost exclusively of pawpaw (Asimina triloba) and 2) lower (although still relatively high) shrub stratum composed solely of American bladdernut (Staphylea trifolia). There was some buckbrush or coralberry (Symphoricarpos orbiculatus), but this otherwise widespread Ozark Plateau shrub was present only in sub-trace quantities in this mesic, relatively cool, north slope forest.

Locally common to dominant forbs included Jack-in-the-pulpit (Arisaema atrorubens), green dargon (A. dracontium), wake robin (Trillium sessile), trout lily (Erythronium americanum), dutchman's breeches (Dicentra cucullaria), and false Solomon's seal or false spikenard (Smilaceina racemosa). Rue anemone (Aneomella thalictroides) and false rue anemone (Isopyrum biternatum) were the earliest vernal forbs in this forest. Mayapple (Podophyllum peltatum) was present at extremely low cover (it was "barely there") which was "sign-significant" for this climax forest vegetation given the nearly ubiguitous presence of this forb in forest, even savannahs, of the Ozark Plateau. Other forbs were mosses and ferns, including walking fern (Camptosorus rhizophyllus= Asplenium rhizophyllum) and Christmas fern (Polystichum acrostichoides). Ferns were not as abundant (general density and cover parameters) as on an east slope sugar maple forest farther downstream (see below).

Dominant grass overall was silky wldrye (Elymus villous) though locally broadleaf woodoats (Uniola latifolia) was common to dominant. Naturalized Kentucky bluegrass (Poa pratensis) was also common at local scale.

Two photographs provided a longer glance (first slide) followed by a shorter glance (second slide) of the range vegetation of this mesic-limestone forest (Neldon, 1987,p. 28; 2005, ps. 122-125). Snag (right side near margin in first slide; right of center in second slide) was sugar maple. Large tree to its left with trunk injury or damage blaze (both slides) was bitternut hickory. Sapling to left of blazed big bitternut hickory with missing crown and profuse generation of long shoots was white ash. Sprouts in front and slightly to left of blazed big bitternut were American elm with a few individuals of slippery elm. Shrubs were pawpaw (taller; more sparse) and American bladdernut (forming colonies; shorter that pawpaw). Smaller trees (not shrubs) at edge of dense forest stand with conspicouos leaves (partial crown in first slide; only one or two limbs in second slide) was sugar maple.

2. Tall hardwoods that like it cool and moist- A mesic-limestone forest on bluffs above a creek in the western Ozark Plateau. A fairly comprehensive list of major species (trees, shrubs, forbs, and grasses) in this tract of forest was given in the immediately preceding caption. Coverage in this caption was limited to specific featured species. Tree at left margin was black walnut. Sugar maples were to the close-by right and also behind the black walnut. Tall tree in foreground left of center was basswood. A young Kentucky coffeetree was to the immediate right of tall basswood and with crowns of the young tree passing in front of the bsswood. The three trees in right foreground were (left to right): American elm, hackberry, and white ash.

Shrub layer (mostly in foregroune) were mixture of pawpaw, American bladdernut, and some flowering dogwood. The only herbaceous species visible at this distance were a large plant of silky wildrye and some leaves of the otherwise scarce Mayapple.

3. At the base of a bluff- By the banks of Modoc Creek in the Springfield Plateau section of the Ozark Plateau (Mountains) some large trees of a mesic-limestone forest created a peaceful sylvan scene that belied the extreme competition for light (and undoubtedly, other resources) in this postclimax forest range vegetation. Tree in left foreground was an American or white elm (no umbrella-shaped crown on this forest dweller). The tree behind (and largely hidden by) the tall American elm with its upper bole leaning right was basswood. To the right (and behind at some distance) of the right-leaning basswood was a smaller sugar maple. Largest tree in this photograph (center foreground) was white ash. Smaller trees to left and right of large white ash were hackberry, including the large tree in right background. (Incidentially, real woodsmen would have noticed the black spot of a varmit in the right background hackberry, and we didn't even need our Black and Tans or Blueticks to tree it.) Smaller trees at right were sugar maple. Most of the young shoots in the understorey were also sugar maple. Regeneration in dense shade is a trademark of this Very Tolerant hardwood.

Most shrubs were American bladdernut. Some pawpaqw were present. The spike of silky wildrye (lower right corner) was conspicuous (and a rangeman's signature on this slide).

If any greenhorns were viewing this who could not locate the coon you might have better luck finding the large rotting log, the species of which could not be determined, that was close by the large white ash (in right center midground). Downed timber, especially big trunks and limbs that require long time periods to rot away, are part of the forest. A tree does not cease to be part of the forest range ecosystem just because it dies. There is life after death in the forest.

Along Modoc Creek, Ottawa County, Oklahoma. Late May (vernal aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

4. A logger's view of trees at the base of a bluff- Vertical "photo-transect" of the larger trees introduced in the preceding slide and caption. The greenhorns' log served as focal point. Largest tree to left of log was the large white ash previously noted. Small tree to immediate left of large white ash was hackberry. Foremost tree (near lower left corner) was American elm. Tree at far left margin (only upper bole in photograph) was basswood. Smaller tree with dark trunk between (and behind) the American elm and the upper bole of basswood was sugar maple-- as were most of the seedlings and saplings in the understorey.

Also visible in understorey were large plants of silky wildrye. Most shrubs (foreground) were American bladdernut.

5. As much light as you get in this woods if you're limited to ground-level- This poorly (barely) lite photograph showed the most light that this immediate location (local habitat) receives once trees have fully leafed-out in this north slope, sugar maple-dominated forest. Biggest tree (21 inches DBH) that was slightly left of center was a dandy sugar maple. Tree to its left (lower trunk at lower left margin) was northern red oak. Small sapling to left of northern red oak was white ash. Dominant shrub was flowering dogwood with eastern redbud the associate shrub species. Main herbaceous (not visible) was the lebuminus forb pointed-leaf or cluster-leaf ticktrefoil or tick clover (Desmodium glutinosum).

6. In its own shade, and more some- Two "photo-quadrants" of the understorey of a mesic-limestone, north slope forest dominated by sugar maple (with bitternut hickory, white ash, basswood, northern red oak, hackberry, and American elm other locally important tree species). There was no doubt as to which was the dominant on this forest range (and most range hungry animals had better like it or go elsewhere). The adult tree (center), saplings (small and large), seedlings, and even root or trunk sprouts were sugar maple.

There was some American bladder, distinguised by its compound (largely trifoliate) leaves, buckbrush or coralberry, and silky wildrye (prebloom). Otherwise, this was an "all-ages gathering" of sugar maple.

The second slide featured shoot or stump sprouting in a sugar maple sapling that lost its crown in a severe icestorm in February (three to three and a half months before time of photograph). This never-say-die small sapling simply started over at the bottom as it were. The ability to reproduce (sexually and/or asexually) in "its own shade" is the defining feature of a species with high tolerance. Sugar maple has a tolerance rating as high as it goes: Very Tolerant. This was according to the Society of American Foresters (Wenger (1984, p. 3) which gave ratings of Tolerant for basswood while white ash, bitternut hickory, hackberry, northern red oak, and American elm were Intermediate.

7. Not dead yet (at least, not quite)- Stump suckering (= coppicing) from an otherwise dead sugar maple on a sugar maple-dominated forest that developed on a bluff above Modoc Creek in the western portion of the Ozark Uplands. These were long or heterophyllus shoots (in contrast to fruit-bearing short shoots). Production of stump suckers is a form of asexual reproduction that is well developed in many hardwood trees and shrubs that are interpreted as having higher levels of Tolerance. Sugar maple has the highest rank of Very Tolerant (Wenger, 1984, p.3). In this tract of north slope, mesic-limestone forest sugar maple had various tree species that were local associates including bitternut hickory, white ash, basswood, northern red oak, and American elm.

Note the Jack-in-the-pulpit and various ferns in front and to side of the trunk and long shoots.

8. Coppicing in bitternut hickory- Sprouting from two stumps of Carya cordiformis along the banks of Modoc Creek in a sugar maple-dominated forest in which bitternut hickory and white ash were the most consistent associate tree species. This photograph taken in late autumn provided the detail of several bouts of suckering or coppicing in two hickories that had suffered repeated injury (most likely from spring wildfires).

Along Modoc Creek, Ottawa County, Oklahoma. November (autumnal aspect); dormancy in hickory.

9. Jack the ash lost its crown- Two slides showing coppicing (=suckering ; production of long shoots) from high up on trunk of a white ash that lost almost all of its aboveground portion in a severe ice storm. This intermediate-sized tree was growing about mid-way up a limestone bluff above an Ozark Plateau stream in a sugar maple-dominated forest (in which bitternut hickory and white ash were most consistent associaties; other associate tree species being basswood, northern red oak, and white or American elm). A severe ice storm "wrecked havoc" on some trees in this mesic-limestone forest (Nelson, 2005, ps. 122-125). The white ash presented here lost its crown in February, but by late May it had regrown these long shoots (stump or snag suckers). White ash is a strongly coppicing species, at least under certain conditions.

Along Modoc Creek, Ottawa County, Oklahoma. Late May (estival aspect; coppicing in white ash).

10. And Jill the basswood came tumbling after- When the crown of the white ash (discussed with the immediately preceding two slides and caption) crashed in a February icestorm it took an neighoring (and even larger) basswood down with it. In fact the basswood was brought even lower as the additional weight combined with wet soil resulted in complete toppling of the basswood.

The first of these two photographs presented immediate local habitat (microsite) by the toppled basswood (including the stump of trunk from which the landowner had cut firewood). The owner had not worked up the small side shoot of this basswood that was on the ground surface (center foreground to left lower corner). The basswood had sprouted profusely all along this secondary bole. (A morphological feature of basswood is on-going or continued production of secondary shoots off of the main (original) tree trunk.)

Also visible in this first slide were resprouting and seedling plants of white ash, sugar maple, and American elm along with American bladdernut and several pre-bloom-stage plants of silky wildrye, the dominant grass in this mesic-limestone, north slope, Ozark Mountains forest.

The second of these slides showed stump sprouting (=suckering= coppicing) of the basswood in more detail.

Along Modoc Creek, Ottawa County, Oklahoma. Late May (estival aspect; coppicing stage in basswood).

11. Past-prime autumn coloration (in sugar maples), but still instructive- Late autumn in a north slope, sugar maple-dominated Ozark forest was still an appropriate time to describe the postclimax climax vegetation of this forested range. This was the same tract of forest (along and above Modoc Creek) that was presented and discussed in the preceding slides of the Sugar Maple Forest section. (See again first photo-caption for comprehensive list of major plant species.). Plants featured in the autumn scene were sugar maple (big trees at extreme left and right margins, Big tree in center midground (midway up the bluff) still bearing green leaves was a northern red oak. Tree with green leaves at far left (left margin) was a chinquapin (chinkapin) oak. Trees with retained dead leaves were sugar maple.

12. Another instructive view of gone-past-autumn color- Vertical look at a sugar maple-dominated forest on a limestone bluff (above Modoc Creek) in the Springfield Plateau of the Ozark Highlands. Largest tree (center foreground; midway up the bluff) and the larger tree on top of the bluff (to left of largest tree) were sugar maples readily distinguished by their large, crooked limbs. Tree in front of and to left of largest tree (and still bearing green leaves) was a northern red oak. The several trees at far right mid- to background included sugar maple, basswood, and chinquapin oak. Most seedlings and saplings of understorey were sugar maple, the Very Tolerant, climax dominant tree species of this mesic-limestone forest (Nelson, 2005, ps. 122-125).

Attention was drawn to the large, flat rock in left-of-center foreground which was limestone.

13. Spring slope- "Photo-transect" on the north slope of the sugar maple-bitternut hickory in early spring. The spring flora of the mesic-limestone forest (Nelson, 2005, ps. 122-125), especially the lower herbaceous layers, that was described in this portion was one of the most unique or conspicuous features of this climax forest range vegetation. This early vernal aspect showed the temporal and spatial variation of this mesic Ozark Highlands forest. Species details were presented in the two immediately succeeding photographs.

The farmer has to "make hay while the sun shines", and so do most of the florest floor-dwelling plants in this sugar maple-dominated plant community. Once the leaves are fully developed on the maples and associated tree species, along with the shrubs, there is inadequate light for most shorter plant species (this includes almost of the herbaceous species). To survive, forest forbs (which dominate the herbaceous layers) must complete their annual cycle of life (= growth cycle) as early as spring temperatures permit their growth and reproduction.

Ottawa County, Oklahoma. April.

14. Details of spring slope- Two "photo-plots" of the vernal herbaceous understorey on a north slope, climax sugar maple-bitternut hickory forest that was introduced in the preceding slide. Species on the north slope of this forest floor included Jack-in-the-pulpit, wake robin, Solomon's seal, false Solomon's seal, wild geranium (Geranium maculatum), green dragon, trout lily, mayapple, Dutchman's breeches, and the fungus known simply as morel (Morchella rotunda).

The first and last of these forest range plant species were conspicuous. Students should try to find some more of the just-listed species in these two photographs. (Like a good matching question not all named species were present, and there could have been a species or two present in the photographs that was not listed. Good Luck.)

Ottawa County, Oklahoma. April.

15. Leaves and fruit of sugar maple (Acer saccharum)- Details of leaves and nearly mature schizocarp of sugar maple. The fruit of maple has been interpreted as either a samaroid schizocarp having two winged mericarps or as two samaras joined together (Smith, 1977, p. 165). Schizocarp is a dry fruit with carpels separated from each other into single-seeded indehiscent segments called mericarps, which in Acer species are winged; samara is also a dry fruit and a winged one that is indehiscent with a single-seed (Smith, 1977, ps. 66, 307).

Ottawa County, Oklahoma. August. Stage of phenology: premature but late fruit stage (immediate or near-term maturity of fruit).

16. Fall colors- Leaves of sugar maple in autumn coloration. This was near peak color (brightness; most reddish, yellowish, or orangish) for what is typical of sugar maple in the Ozark Highlands. Usually the colors of sugar maple in one of the most western (and marginal) extremities of the biological range of this mesic species are less brilliant and extreme than those in more eastern (especially northeastern) portions of this species' range.

Ottawa County, Oklahoma. October. Leaf fall was immanent.

17. Clusters of fruits in box elder (Acer negundo)- The fruit of maple species has been regarded as either a samaroid schizocarp consisting of two winged mericarps or as two samaras joined at their apexes. Throughout much of the Ozark Plateau Region box elder blooms and sets fruit earlier than sugar maple with which it is sometimes associated on bottomland forests. Box elder is a favored feed of beaver whereas this largest rodent in North American seems to avoid sugar maple.

Along Lost Creek, Ottawa County, Oklahoma. April.

18. American bladdernut (Staphyla trifolia) in understorey- One of the dominant shrubs in a sugar maple-bitternut hickory forest that developed on a north slope of a limestone bluff above Modoc Creek. American bladdernut was the sole shrub species of a lower shrub layer (vegetational stratum) on a lower elevational zone that extended from stream bank upslope to the point where there was a higher or upper zone consisting of one major shrub layer (dominated by eastern dogwood with eastern redbud as the associate shrub). There was also a taller shrub stratum in the lower zone (near the stream) that was made up almost largely of pawpaw. Pawpaw and bladdernut did not "mingle" or the layers they dominated overlap to any appreciable extent. Rather these two shrub species were largely segregated, although this was certainly not entirely the case.

American bladdernut is one of the more common shrubs in more mesic forests in the Ozark Plateau, especially along watercourses and bases of bluffs.

Bluffs above Modoc Creek, Ottawa County, Oklahoma. October.

19. New flowers and old fruit- A leader of American bladdernut retained one of last year's fruits while new inflorescences were in full-bloom during early spring along a north-facing bluff in the Springfield Plateau of the Ozark Hihglands. This was a dominant shrub in the climax sugar maple-bitternut hickory forest of which it was part.

Bluffs above Modoc Creek, Ottawa County, Oklahoma. April.

20. Flowers of American bladdernut- Flowers of bladdernut grown in clusters that hang down in a racmeme-like arrangement. These inflorescences often occur on tips of smaller branches off of the main limb of the shoot.

Bluffs above Modoc Creek, Ottawa County, Oklahoma. April.

21. Nuts! Bladdernuts- The fruit of American bladdernut is a inflated or bladder-like pod consisting of three subdivisions or compartments. Bladdernut is one of two other woody plant species found in the Ozark Highlands that are in the Celastraceae, staff-tree family. Burning -bush or eastern yahoo (Euonymus atropurpureus) and bittersweet (Celastrus scandens) are these other two species, both of which are distinctive or even unusual and niether of which is common.

Bluffs above Modoc Creek, Ottawa County, Oklahoma. October.

24. Walking fern (Camptosorus rhizophyllus= Asplenium rhizophyllum)- This unique (and rare) fern was growing on a moss-covered limestone bluff above a creek in the western oak-hickory forest of the Ozark Plateau. The common name of this species comes from it's form of asexual reproduction. The pointed tip of the frond (the leaf of a fern) often roots and produces a new daughter unit (a module or ramet) which, upon complete development, can repeat this pattern of propagation. This phenomenon was "going hog-wild" in the specimen shown here. Walking fern also reproduces sexually as do other ferns by producing and releasing spores from sori (singular, sorus; the clusters of sproangia in ferns) on the undersides of their fronds.

Fern was growing amidst or a "carpet" of the gametophytic generation of a "true moss" (see slides below).

On a limestone bluff above Modoc Creek, Ottawa County, Oklahoma. March.

The next series of photographs and their captions was of another sugar maple-dominated forest also along Modoc Creek in the Springfield Plateau section of the Ozark Highlands. This forest tract was an east slope forest located less than one mile downstream from the sugar maple-dominated forest just described. The east slope sugar maple forest had fewer species--except for ferns--overall. Most conspicuous was white ash (versus bitternut hickory) as the most frequent associate tree species followed by northern red oak and chinquapin oak. Basswood, bitternut hickory, and American elm were infrequent and did not approach associate species status even in local stands.

This east slope, limestone bluff, sugar maple forest--another variant of mesic-limestone forest (Nelson, 2005, ps. 122-125)-- was postclimax in the general Ozark Plateau oak-hickory forest. The sugar maple-dominated forest described in the following portion was contiguous with a mesic bottomland forest (Nelson, 2005, ps.147-150), except for the separation by stream corridor of Modoc Creek, that was described later in this section on Miscellaneous Forest Types.

26. East slope sugar maple forest- Another example or phase of sugar maple-dominated forest in the Ozark Plateau was also found along Modoc Creek. This forest tract had developed on an east slope and differed from the sugar maple-bitternut hickory forest type or subtype (variant) that developed on a north slope of Modoc Creek located only 3/4ths to one mile upstream from the forest vegetation described here. This sugar maple-dominated community was much less species-rich except that it had more ferns including maidenhair (Adianthum pedatum) and Christmas ferns (Polystichum acrostichoides). In this forest communitysugar maple was sole dominant with northern red oak and chinquapin oak (Quercus muehlembergia), and white ash being local associate species. Mature trees of these two oak species were generally larger than all but a few of the slower-growing sugar maples.

There were also larger, less abundant trees of sycamore, bitternut hickory, and black walnut. Most regeneration was of sugar maple with somewhat less reproduction in box elder and northern red oak with these two species swapping places depending on microhabitat. Co-dominant shrubs overall (and of two different layers)were American bladdernut (taller) and spicebush (shorter-growing). The tallest shrubs (those of the taller shrub and/or lower tree layer) were flowering dogwood (more abundant) and eastern redbud. Pawpaw was present, but was primarily on the adjacent (and other side of the creek hackberry-American elm-sycamore-eastern cottonwood bottomland forest). Lanceleaf buckthorn (Rhamnus lanceolata) grew in association with American bladdernut, and though usually overtopping the latter, R.lanceolata was uncommon. Almost no herbaceous species other than ferns. Occasional plants of Virginia or silky wild-ryes or beakgrain (Diarrhena americana) were present, but these-like woodreed grass (Cinna arundinacea)-were usually confined to rock or gravel bars away from the sugar maple forest. Grasses were much less common than on an adjacent hackberry-elm-box elder forest on the stream floodplain (described below).

The two wide-view photographs shown here presented species composition and structure of a postclimax sugar maple forest that developed on an east-facing limestone bluff along a typical stream in the Ozark Plateau. In the first of these photographs a large hackberry (largest trunk; dead center of photograph) and black walnut (tree to right of big hackberry) added some diversity to an otherwise solid stand of uneven-aged sugar maple. In the second of these slides an immense sugar maple (25 inch DBH) overlooks a nearly "pure" stand of its species (undoubtedly many of which were its own offspring). Even smaller adult trees at right were mostly sugar maple. Lanceleaf buckthorn (Rhamnus lanceolata), an exmple of which was tallest shrub in front (and slight to right) of large sugar maple, American bladdernut, flowering dogwood (conspicuous in right foreground), and American hazlenut (Corylus americana) were the primarily shrubs vbisible in the second photograph.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

27. Broad view of an Ozark Plateau bluff and its forest- A wide-angle "photo-transect" on an east slope of a limestone bluff along a typical stream in the western part of the Ozark Highlands on which a postclimax sugar maple-dominated forest (with white ash and, to lesser extent, northrn red oak were associate tree species) had developed. This was a mesic-limestone forest (Nelson, 2005, ps. 122-125) that in monoclimax theory (Clements, 1916) was postclimax to the regional (climatic) climax oak-hickory forest. This photograph introduced forest range vegetation that was viewed at increasingly closer-in scale in subsequent slides.The huge sugar maple at the right served as a "landmark" and featured topic in the subsequent slides. The smaller tree in left midground with the right angle-like trunk leaning sharply to the left was another sugar maple. The tree in upper left margin (upper right corner) was a northrn red oak.

Shrub species included American bladdernut (generally the dominant shrub), lanceleaf buckthorn, flowering dogwood, shadbush or, as it is also known, eastern serviceberry, and eastern redbud. There were only occasional herbaceous species that were not forbs, most of which were ferns, as most grasses and sedges grew closer to the creek. Along banks of the stream (Modoc Creek) there were occasional individuals of silky or Virginia wildryes, beakgrain, or giant woodreed. Most common ferns were Christmas fern and maidenhair fern.

Regeneration of climax dominant trees (mostly sugar maple, white ash, and northern red oak) comprised much of the lower layers of the understorey as the young of these trees ranged from seedlings to large saplings.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

28. Postclimax and "pure"- An east slope of a limstone bluff above an Ozark Plateau stream provided the setting for a "nearly pure" stand of sugar maple. In the Clementsian monoclimax theory this was a consociation of Acer saccharum that was postclimax vegetation where the climatic =regional or zone) climax was oak-hickory forest, the Oak-Hickory Forest Region (an association) of Braun (1950, ps. 35, 162-191). The mighty sugar maple in center foreground was the sugar maple described as "huge" in the immediately preceding photograph. This large maple had a large (by standards of its species) lanceleaf buckthorn to the right and in front of it. Shrub in lower right corner was flowering dogwood. Shrub species in left foreground included American bladdernut, pawpaw, and flowering dogwood. Many of the shrubs higher up on the bluff were shadbush or, as is also known, eastern serviceberry. Almost all tree regeneration was sugar maple with traces of northern red oak and white ash.

Details of understorey of this immediate (local) site was given in the next slide and caption.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

29. On the bank- On the bank of a typical stream in the Ozark Highlands there was a multi-layer understorey in a sugar maple-dominated forest on an east slope of a limestone bluff. Tree trunk in center midground was that of the mammoth sugar maple that served as the "landmark" in the immediately preceding slide. Shrub to right (and with its upper shoot growing to the right)was lanceleaf buckthorn. Most of the other shrub cover was that of American bladdernut. Ferns in edge of stream bank were Christmas fern, a major forb in this mesic-limestone, postclimax forest. Also present was a ground layer composed of luxuriant cover of moss, the species of which this bryophyte-ignorant author knew not.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

30. A bluff full of beauties- An east-facing limestone bluff aligned along Modoc Creek in the western part (Springfield Plateau) of the Ozark Highlands supported a mesic forest dominated by sugar maple (with white ash and, secondly, northern red oak as associate tree speceis). This forest range was postclimax in the general oak-hickory forest of the Ozark Mountains.

This photograph featured species composition (especially of dominants and associates) and structure of this southern and western outlier of the sugar maple forest cover type. In this stand white ash was the clear associate to sugar maple, but with northern red oak a close "runner-up". Large tree at right midground (and midway up the bluff) was sugar maple. The large tree to the right of this sugar maple (along right margin of photograph) was northrn red oak. The adult tree closest to the big sugar maple (left of it with its upper bole in the crown by large left limb of the maple) was white ash as was the largest tree in this photograph which was largely obscured by two smaller hackberry trees. The largest tree, the white ash, had lost much of its crown which retained a large left-leaning limb.

Major shrub was American bladdernut, but flowering dogwood, American hazelnut, shadbush, and eastern redbud were present to locally common.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

31. Sugar maple-white ash stand- Composite view of species composition and structure of a mesic-limestone (east slope; bluff habitat) with sugar maple the dominant and white ash the associate species. Biggest tree (right side) was sugar maple. Second largest tree ((left of center midground) was white ash. Most regeneration was sugar maple and white ash, including the larger saplings in baqckground. Hackberry at far left. There were two shrub layers: 1) taller layer dominated by flowering dogwood, lanceleaf buckthorn, and American hazelnut (the large shrub in front of the big sugar maple) and 2) lower layer almost exclusively American bladdernut but with considerable poison oak/ivy. Grape vines grew to top of canopy and formed a "unifying wooden thread" among the various layers of forest range vegetation.

Herbaceous layer(s) consisted primarily of Christmas and maidenhair ferns. Mosses made up a lush ground layer (the lowest layer of vascular plants).

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

32. Hole in the canopy- Example of gap or patch dynamics in a sugar maple-dominated east slope bluff forest in Ozark Plateau. A postclimax forest range in the general oak-hickory forest had extensive feeding by beaver (Castor canadensis) 17 years prior to this follow-up photographic session. Beaver killed a high percentage of the largest northern red oak (along with lesser browsing on American elm, box elder, sycamore), but fed on very little sugar maple. This gap was created 17 years earlier when beaver girdled three massive northern red oak (all were between two and a half and three feet DBH) which died in the spring following winter browsing a few months earlier (the three oaks never really leafed-out). The light-colored trunk in right background was the snag of the only one of the three northern red oaks that had not fallen.

Death of the three giant oaks left such a gap in the canopy that the stage was quickly set for the process of recovery of the forest vegetation through secondary plant succession. Such vegetation dynamics--to use the term made famous by F.E. Clements who adopted it from H.C. Cowles--is studied as patch or gap dynamics which is unique from the perspective of small spatial scalet as in, say, the larger spatial of a large forest clearcut, blowdown, fire, or old-fields as in cut-over lands.

Most tree regeneration was of sugar maple (including the sugar maple sapling in lower right foreground) and white ash. The large limb, which was shown at close range in the next (succceding) slide, was off of a large northern red oak (outside of camer range at left) brought down by a February icestorm. The falling red oak limb brought down canopies of two medium-sized black walnut trees (left midground). Beneficiaries of this tree damage were understorey plants, espceially herbaceous species the most common of which were maidenhair fern and the pioneer composite, giant ragweed (Ambrosia trifolia). American bladdernut was the most common shrub in the gap.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

33. Ground level and ground zero- Lower and mid levels of forest range vegetation in a seventeen-year old gap in a sugar maple-dominated forest that was made when beaver girdled three massive northern red oak. In the 17 years following beaver-felling of old-growth trees the "dynamics of vegetation"--to borrow a title for selected writings of F.E. Clements (Allred and Clements, 1949)--had resulted in re-establishment of sugar maple and white ash, the two major (dominant) climax tree species for this forest site. Of course trees of these two climax domiants were still small, but the species composition had quickly progressed to that of the climax forest vegetation. The dominant shrub was American bladdernut which, while not as abundant as on the banks of the stream (Modoc Creek), still had appreciable cover and density.

The largest and one of the most common herbaceous species was giant ragweed. It was not known whether this pioneering annual composite was more plentiful due to (or even present only after) disturbance due to tree damage from the February icestorm .There was very occasional cover of Virginia wildrye, but in more shaded local habitats the most common forb was maidenhair fern.

The sugar maple sapling (right-of-center foreground), that became conspicuous within a couple or three years following death of three massive northern red oaks by beaver girdling, had in the interim become well-established and received limited beaver feeding (note blaze on lower trunk). Obviously beaver abandoned this feeding station quickly and before the sugar maple sustained enough feeding damage to be life-threatening, at least in the short-run. (Reduced performance or even death might be possible via disease entry through the debarking wound where beaver fed, however limited that was.)

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

34. Life among the fallern on the forest floor- A severe February icestorm brought down a large part of the crown of a northern red oak (which in a chain reaction brought down crowns of neighboring black walnut as shown in a preceding photograph). About six months later, as shown in this photograph, maidenhair fern and regenerated (seedling and/or root-sprouting) sugar maple were apparently benefiting from the ecological windfall caused by ice.

Along Modoc Creek, Ottawa County, Oklahoma. July (aestival aspect). FRES No. 15 (Oak-Hickory Forest Ecopsystem), but a postclimax maple forest therein (Braun, 1950, ps. 168-169) so closest Kuchler unit was K-90 (Maple-Basswood Forest). SAF 27 (Sugar Maple). Either sugar maple postclimax in Oak-Hickory Series, 122.11, or Maple-Basswood Series, 122.15, of Northeastern Deciduous Forest in Brown et al.(1998, p. 37). Mesic-limestone forest (Nelson, 2005, ps. 122-125). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

35. A lingering death and the tragic end of their reign- The first act of the unfolding forest drama (tragedy or comedy was left up to viewers' discretion) that was revealed above began with the empty stomach and ever-growing incisors of beaver(s). Bark-feeding by beaver during winter months left three very large northern red oaks (each over two and a half foot DBH) girdled and soon-to-be-dead in an east slope, mesic-limestone, sugar maple-white ash climax forest. The tree in left background as well as the trunk in midground, and partially concealed by the foremost tree, were all northern red oaks and completely girdled. Death would "officially" wait until spring when, with rising sap, these once-magnificant oaks would fail to leaf-out. (As it turned out, the preformed, terminal buds of these oaks did not fully open before they fell off indicating that trees were dead.) None of the three trees sent up any stump sprouts. Lack of suckering (production of basal shoots) is the typical or normal physiological response of old hardwood trees. Death of the entire tree (not just top-kill) was "sure and swift" for all three mature "timber-ripe" oaks.

These three northern red oak were some of the largest trees in this east slope, limestone bluffs forest. Only a few sugar maple and white ash reached similar size. Trees of these latter two species were not browsed. This was a textbook example of feeding selectivity (= selective browsing). Locally these three oaks were (had been) "far and away" the largest trees that controlled the largest portion of the canopy (ie. had the greatest impact on how much and for how long light reached lower levels of the forest). Loss of the "masters" of the forest canopy set the stage for secondary plant succession on the bluffs above Modoc Creek.

Oange inner bark is characteristic of several of the red oak species (Erythrobalanus subgenus) , especially black oak, and it showed prominently on the three girdled northern red oaks featured here. "Reading sign" revealed that beaver gnawed higher (almost three feet above ground level) on the upslope side of the trunks showing these rodents (largest rodent species in North America) fed on their hind legs on the high side of trunks while "standing on all fours" on the downhill side.

Tthe author's 38-inch, hickory walking stick was placed lengthwise at base of the foremost (and largest) oak for scale.

Historically there have been high population densities of beaver along Modoc Creek and other streams in this local area. As a boy the photographer's younger brother trapped beaver for several years along these streams. He caught a few adult male beaver that exceeded 50 pounds in weight. These were (are) bank-beaver. The beaver do occasionally build high dams on streams causing localized flooding of bottomland forests, but as far back as local observers can remember beaver never built stick-and-mud lodges. Rather, long tunnels dug far back into creek banks served as beaver dens.

As was shown in this photograph adult beaver often fed at considerable distances from streams. This was never much more than half-way to top of bluffs (usually feeding was limited to approximately the lower one-third of bluff height). In other words, trees that grew high up on bluffs were safe from beaver browsing or, from a forester's perspective, beaver depredation.

36. Standing tall, proud, and dead- On east-facing, limestone bluffs above Modoc Creek the tallest and largest-diameter (over 30 inches DBH) of three northern red oaks was quickly dying (after only partially leafing out) following bark-feeding by beaver during the immediately preceding winter months. Death of the three northern red oaks was complete in a month or month and a half following bud-opening. Most of the neighboring (surrounding) trees--all of which were considerably smaller and, presumedly, younger--were sugar maple and white ash plus a few black walnut.

Death of the largest--and locally dominant--northern red oaks created a forest gap or patch almost as rapidly as windthrow (blowdown) or lightening strike. Beaver were not only hungry and "eager" they were lethal. The stage was preparing for the second act of patch or gap dynamics.

37. The new living among the old dead- Two local "photo-quadrants" showed details of and adjacent to the largest of three northern red oaks that died after being girdled by bark-feeding beaver over a period of roughly two to four months prior to an aborted effort by oaks to leaf-out in spring. The first fact to "leaf-out" from the "crime scene" at this photographer was that the large oak (three foot DBH) was largely hollow. The trunk of this otherwise healty northern red oak (prior to beaver strike) consisted almost solely of sapwood. This condition of "hollow-heart" (by which it is known among Ozark sawmill operators) probably had little, if any, influence on this tree because 1) heartwood is dead and provides no life-supporting function and 2) a hollow tree, like many hollow cylinderical things in nature (grass culm, bird quill) is almost as strong as trees with solid (non-hollow) trunks. Therefore, beaver did not bring down a tree that was dying (they killed a sound, healthy tree). On the other hand, beaver did not destroy a valuable lumber tree and cause economic loss to the firm or landowner. The huge tree was useless for lumber and was fit only for fuelwood (the trunk would not have made a saw log and loggers would have wasted their time felling the tree). In fact, beaver conducted their own version of "site preparation" by clearing the way (making resources available and conditions more favorable) for younger trees that could grow sound boles for future (and more valuable) wood products.

Let's here it for the beaver! Plus, the browse (bark) of the oaks contributed to the production of more beaver plew (pelts), another product of the forest. Why, it might even stir that younger brother to re-run his trap line (at least renew his subscription to Fur, Fish and Game).

The hollow-trunk northern red oak was an example of "over-ripe" timber known technically as overmaturity or overmature which when applied to individual trees refers to the condition of having reached the "...stage of development when it is declining in vigro and health and reaching the end of its natural life span" or "...one that has begun to lessen in commercial value because of size, age, decay, or other factors" (Helms, 1998).

It was possible (probably likely) that once it was dead, and with weakened and soon-rotting sapwood, the hollow oak crashed sooner than if it had been solid. In point of fact, one of the three girdled northern red oaks was still standing 17 years following its death (the snag standing conspicuously on the bluff in two of the photographs presented above). The solidness of this trunk was not determined by the author because cutting into the tree to determine its state of soundness could have caused it to fall when it might otherwise have continued to stand for decades. (Besides only a hollow-headed idiot would risk life and limb--catch the pun--to tote a double-bit up such a steep, slippery slope to cut a tree that was useless for wood. Now slinging a 35mm SLR Nikon for educational purposes--that is, to chop out ignorance--is a different grade of lumber.)

The other--and more relevant--fact from forest vegetation and succession standpoints was the tree species that were replacing the former "mighty oak". Saplings and seedlings of sugar maple began almost instantly to fill the gap created by the beaver. Obviously, maple saplings had been growing beneath this northern red oak prior to beaver "attack". Furthermore, sugar maple is rated as Very Tolerant (Wenger, 1984, p. 3) so that continued survival and growth of sugar maple was likely even with continued canopy cover of the potential still-living oak. Nonetheless, more resources and modified conditions (including increased light, space, and soil moisture) undoubtedly was of some benefit to sugar maple growth and regeneration. There were also several age-size classes of white ash (and of northern red oak) in the gap formed by death of the large northern red oak.

The tree behind the fallen oak was one of the other two northern red oaks killed--but still standing--by beaver.

38. Down and out (and after only one "beaver strike")- The "long view" of the largest of three northern red oak killed by beaver girdling in the preceding winter. This hollow-trunk old patriarch fell across the channel of Modoc Creek creating a forest gap in which already active-growing sugar maple and white ash (even a few young northern red oak) were ready to utilize more available resources and different conditions (not least of which was more light, space, and soil water).

It would be humanly impossible to know all of the ways in which death and crash of this old-growth speciment affected life in this east slope climax forest, or of the creek below it or the bottomland forest (another forest cover type and separate tract of forest) separated from it by the stream. Even the trunk and crown of the oak across Modoc Creek could conceivably have some impact on some organisms. For instance, it could permit some animals to cross to other side of the stream. The potential barrier to movement, which though not exactly a grand canyon, had been breached. This was of no momemt to a coon, but it could be determinative to a biped (such as the hillbilly who took this photograph).

Above Modoc Creek, Ottawa County, Oklahoma. September, 1991.

39. Bridge to a new forest and return of the final order- Two views from opposite ends of the rotting log of a large northern red oak that was killed by bark-feeding beaver and fell in the first summer following its death in early spring. The tall tree in left foreground of first slide was a sugar maple. Much, probably most, of the tree regeneration was also of sugar maple though this was accompanied by that of white ash, northern red oak, bitternut hickory, hackberry, and black walnut. Sycamore, the dominant pioneering or colonizing tree species along stream channels and freshly scoured bottomlands, was not released or encouraged by loss of northern red oak.

Shrub species along this stream bank and the sides (slopes) of a limestone bluff above included American bladdernut, flowering dogwood, lanceleaf buckthorn, pawpaw, eastern redbud, and shadbush. These species were aligned along the slope from stream bank to top of bluff with bladdernut, lanceleaf buckthorn, and pawpaw typically restricted closer to water while shadbush grew highest up on the bluffs farthest from the stream. Flowering dogwood and eastern redbud generally grew all across this elevational gradient.

Understorey herbs ranged from colonizing species like annual giant ragweed and mare's tail (and where did that seed come from?) and the hugh tap-rooted, perennial pokeweed to maidenhair and Christmas ferns.There were a few individuals of the two grass species, woodreed and beakgrain. Mosses grew on rocks, logs, tree trunks, etc.

Above Modoc Creek, Ottawa County, Oklahoma. July,1997.

40. The young beneficiary (an immediate heir after assination)- A small pole of white ash was the largest tree above sapling size closest to the beaver-killed (and soon crashed) northern red oak described above on the east slope of a bluff above Modoc Creek that supported a climax sugar maple-white ash forest. Sugar maple (sole climax dominant), northern red oak, bitternut hickory, hackberry, and black walnut were generally the most abundant tree species and, not surprising, these species had the most regeneration in the gap created by death of three large northern red oaks. Of these, sugar maple was followed by white ash in general abundance (cover, density, etc.) as the major species to benefit from death of large, mature (actually, overmature) northern red oak. Not only were did sugar maple followed by white ash furnish the largest individual trees and greatest canopy cover, they were also the species which had greatest apparent (quite obvious) reproduction. Ergo, a sugar maple-dominated forest in which white ash was the associate species.

Above Modoc Creek, Ottawa County, Oklahoma. June, 1997.

Concluding observtion with regard to browsing by beaver- On this stream-bordering, bluff forest (an east slope form of mesic-limestone sugar maple forest) feeding by beaver had a major impact on existing forest composition and structure and on future forest development (revegetation). Beaver were a major biotic factor that at local scale were a major cause of denudation and subsequent changes in the forest plant community via secondary plant succession.

Beaver preferentially browsed northern red oak while largely leaving sugar maple and white ash untouched. Defoliation of some of the largest and oldest northern red oak by complete girdling resulted in quick death of some of those individual trees that had greatest control of canopy (forest) cover. Elimination of forest trees with some of the largest canopies produced forest gaps and patch dynamics. The main tree species to benefit from death of northern red oak by beaver and openings in the forest canopy created by such death were sugar maple and white ash, the climax dominant and associate of this forest which was a subtype of the sugar maple cover type, SAF 27 (Eyre, 1980, p.30). Some northern red oak--typically smaller and younger trees--was unbrowsed and remained in this forest as an important (though not an associate) species.

Northern red oak was most likely a subclimax tree species having some large, long-lived (and lucky!) trees that persisted into the climax forest vegetation dominated by sugar maple with white ash as its associate (at least, major associate) species. Selective browsing by beaver hastened dominance by and general increased cover of sugar maple and white ash.

Thus it appeared that sugar maple-dominated forest in the greater oak-hickory forest of the Ozark Highlands were partly a result of zootic influence and not just an edapho-topographic climax. Conversely, there were other tracts of sugar maple forests along this same stream (including a sugar-maple-bitternut hickory subtype of SAF 27) which supported no beaver populations and in which northern red oak was a major constituent but not an associate species.

While beaver ignored or even avoided sugar maple in these forests they readily consumed bark and harvested saplings and smaller branches of box elder, the other Acer species on this tract. Box elder was uncommon on the sugar maple-white ash forest on the east-facing bluff above Modoc Creek, but box elder was locally a major species on the adjacent bottomland forest (just across the channel of Modoc Creek) where it was readily and regularily fed on.

In contrast to browsing selectivity by beaver on a subclimax species (and avoidance of climax tree species) in this forest, a representative tract of SAF 27, beaver had a preference for and browsed selectively on climax American elm and hackberry on a bottomland forest, a representative of cover type SAF 93. These two tracts (and representatives of two forest range types) were contiguous except for separation by the narrow stream channel of Modoc Creek. On the bottomland forest the climax tree species were decreasers under beaver bvrowsing whereas on the adjoining bluff forest (and a different forest cover type) the climax tree species were avoided while beaver exhibited browsing selectivity for an important subclimax tree species which was a decreaser species..

Apparently there has been little evaluation or even recorded observations on the affect of beaver browsing on the development and compostion of forest range communities. Two interesting and extremely detailed studies on impacts of beaver on North American forests were included as chapters 18 (Donkor) and 19 (Smith) in the reference, Plant Disturbance Ecology, edited by Johnson and Miyanishi (2007, ps. 579-671).

A thrid series of slides and captions presented a third tract of sugar maple-dominated forest. This was also a third variant of form of the sugar maple forest cover type (SAF 27) in the Ozark Highlands which is the more westerly extent of the oak-hickory forest in general, the Oak-Hickory Forest Region of Barun (1950, ps. 35, 162-191). In monoclimax theory (Clements, 1916) sugar maple-dominated forests are postclimax vegetation in the climax oak-hickory forest region. Viewed from the polyclimax or climax pattern theories proposed by Tansley (1926) and Whittaker (1953), respectively, sugar maple forests are edaphic, topographic, etc. climaxes within the general or more widespread climatic climax (oak-hickory forest). By any of these interpretations sugar maple forests are the potential natural vegetation (Kuchler, 1964).

Just as sugar maple-dominated forests in the general oak-hickory forest are variants of this regional forest (sugar maple forests usually include an oak and/or hickory species as the associate) so too are there variants (variant forms) of the generic sugar maple forest. The first series of photographs and their captions in this sugar maple section of Oak-Hickory Forests-II was devoted to the sugar maple-bitternut hickory variant and the second series of photographs-captions dealt with the sugar maple-white ash variant which were subtype 4 and subtype 3, respectively, of the sugar maple forest cover type, SAF 27, (Eyre, 1980, p. 31). The current (third) series of slides dealt with a sugar maple-northern red oak variant. This subtype was not noted by the Society of American Foresters description (Eyre, 1980, p. 31). Nor was it described by Steyermark (1940) or Braun (1950). Likewise, the SAF description did not include the sugar maple-white oak subtype of Steyermark (1940) and Braun (1950).

It was somewhat surprising that Steyermark (1940) did not identify and describe the sugar maple-northern red oak variant because northern red oak is more mesic in its general habitat requirement than bitternut hickory and, even more so, than white oak. In moisture regimes of these tree species habitats, sugar maple is closer (more mesic) to northern red oak than to white oak or bittrnut hickory. In fact, among the three tracts of sugar maple forests described herein (western edge of Springfield Plateau of Ozark Highlands) northern red oak was the most consistently represented associate species. Nelson (1987, p. 28) listed the first three dominant plants of mesic-limestone forest as (in order): northern red oak, sugar maple, and white oak. In the first two tracts of sugar maple-dominated forest described above northern red oak was of lesser importance than bitternut hickory and white ash, but northern red oak was present at greater cover, density, frequency, etc. in all three tracts than the two associate species (other two species, if northern red oak was also an associate species).

The sugar maple-northern red oak was the least mesic and most exposed of the three forest tracts described herein. This third variant form os sugar maple-dominated forest was a north slope (and limestone) forest, but it was not near a stream and more upland than bottomland forest. It was about two miles (or less) from the second tract (east slope) of a sugar maple-dominated forest, and with white ash as overall associate species.

This third example of a sugar maple-dominated forest, or in this case co-dominated by northern red oak (Quercus rubra= Q. borealis), was on a steep north slope less than 2 miles from the two sugar maple forest stands along bluffs of Modoc Creek. The forest community featured next was a dry-mesic limestone forest (Nelson, 2005). This one was also in Ottawa County, Oklahoma; July, 2007). In strictest sense sugar maple was sole and defining dominant because most regeneration-especially in deeper shade-was of Acer saccharum and not Quercus rubra even though the latter was reproducing on some better-lite microsites (sometimes by established maples). Other species represented by occasional mature (and large) trees included bitternut hickory (Carya cordiformis) and white ash (in roughly equal proportions) along with lesser cover of basswood, all of which are climax species on this cover type and site. At upper (and drier) habitats in this forest chinquapin oak had both mature trees and regeneration. This species was regarded as a local climax member of this forest. Black walnut survived in more open spaces where it probably established in some gap and, having captured its share of canopy, survived to adulthood. At other spots in this forest black walnut succumbed to competition (was shaded out) by sugar maple and northern red oak. Major understorey (sub-canopy) shrubs included both eastern redbud and flowering dogwood throughoutalong with American bladdernut and pawpaw these latter two of which were limited to lower, more mesic habitats.

The lower ground shrub layer was comprised mostly of Virginia creeper (Parthenocissus quinquefolia), but like the common, well-distributed summer grape (Vitis aestivalis), this woody climber ascended into the canopy. Poison oak/poison ivy (Rhus toxicondendron) was present, but was less common than in drier forests. Dominant forbs were tick clovers (Desmodium nudiflorum and D. glutinosum). Forbs that were locally abundant (in a relative sense) included Jack-in-the pulpit, Bloodroot (Sanguinaria canadensis), and wild ginger (Asarum canadense). An uncommon (and uncommonly striking) forb was blue cardinal flower of giant lobelia (Lobelia siphilitica). The only graminoids were unidentified species of Carex (only non-fruiting specimens present).

These photographs were taken at abut 1330 hours Central Standard Time to get maximum direct light, but even then there was too much shade (too many shadows) to be able to catch key features such as bark. Ergo: not many good shots. Will try "next year" (wait until next summer) using with light cloud cover to get diffuse light.

41. Looking in on more sugar maple in the Ozarks- Exterior view of a north slope, mesic sugar maple-northern red oak forest at western extreme of the Ozark Plateau, and of the Oak-Hickory Forest Region (Barun, 1950, ps. 35, 162-191), in which this island of the sugar maple cover type (SAF 27) is postclimax (Clementsian monoclimax theory) or an edaphic or topographic climax (Tansley polyclimax and Whittaker climax pattern theories). The small pole-size trees were sugar maple. The tree species higher upslope (behind maples) included three oaks: chinquapin (chinkapin), northern red, and black oak with the latter more abundant on the drier, higher part of slope.

Shrub species included American bladdernut (the most abundant shrub in understorey shown in this photograph), pawpaw (second most common shrub here), flowering dogwood, and eastern redbud. The latter two shrub species were more abundant in the tract overall just not in the sample of the forest plant community presented here. Virginia creeper formed the bulk of a lower shrub laye,r but along with the less common summer grape, this woody climber ascended into the canopy layer.

Relatively little cover of herbaceous species, but the major forbs two species of ticktrefoil (Desmodium nudiflorum an D. glutinosum). Other forbs that were locally (and relatively) abundant in this forest vegetation were Jack-in-the-pulpit, mbloodroot (Sanguinaria canadensis), and wild ginger (Asarum canadense). An uncommmon (and uncommonly striking) forb wqas blue cardinal flower of giant lobeila (Lobelia siphilitica). The only graminoid observed by the author was an unidentifiable (pre-bloom) caric sedge (Carex sp.?).