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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.
The classic and still-definitive work on forests of eastern North America (approximately east of the 98th meridian) is the life's work of Dr. Lucy Barun (1950). Braun interpreted this entire vegetation as one great forest formation existing as a mosaic of forest regions which in turn were made up of community units that she labeled variously as belts, areas, districts, sections, divisions, etc.
"The Deciduous Forest Formation of eastern North America is a complex vegetation unit most conspicuously characterized by the prevalence of the deciduous habit of most of its woody constituents. This gives to it a certain uniformity of phsiognomy, with alternating summer green and winter leafless aspects. Evergreen species, both broad-leaved and needle-leaved, occur in the arboreal and shrub layers, patticularly in seral stages and in marginal and transitional areas. They are not, however, entirely lacking even in some centrally loocated climax communities" (Braun, 1950, p. 31)."The Deciduous Forest Formation is made up of a number of climax associations differing from one another in floristic compositon, in physiogonomy, and in genesis or historical origin. While the delimitation of associations may be made on a basis of dominant species, and it is from these that the climax is named, dominants alone fo not suffice for the recognition of these units. …Although the delimitation in space of an association is difficult, if not impossible, it is entirely possible to recognize and to map forest regions which are characterized by the prevalence of specific climax types, or by mosaics of types. These regions are natural entities, generally with readily observable natural boundaries based on vegetational features. …Forest regions must not be confused with climax associations. Even though a region is named for the climax association normally developing within it, it should not be assumed that the region is coextensive with the area where that climax can develop.Each of the several climaxes, although characterizing a specific region, nevertheless occurs in other regions." (Braun, 1950, p. 33-34).
Braun (1950, ps. 35-37) listed nine forest regions making up the Deciduous Forest Formation of eastern North America:
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 minor rearrangement as series in the fairly comprehensive system of vegetation (primarily, climax; secondly, disclimax and subclimax) used in A Calassification of North American Biotic Communities by Brown et al. (1998, ps. 37-38). 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 Northeastern Deciduous Forest biotic community and Mixed Mesophytic Series and Pine Series within Southeastern Deciduous and Evergreen Forest biotic community. The Brown et al. (1998) series were included below following SAF and/or SRM cover type designations.
The consistent and persistent use of the eastern deciduous forest associations of Braun (1950) by the foremost contemporary ecologists provides the beginning student of Ecology with a textbook example of the necessity of learning the fundamental concepts— and the language(s) thereof —that are the foundation of his selected field of Biology. No ecological monograph, including those of John E. Weaver or Victor E. Shelford, ever used Clementsian concepts and terminology any more consistently or with any more practical application than did Braun (1950). All three of these (and there were others besides these) patriarchal ecologists of North American vegetation left future generations with not only the seminal but also the definitive treatises of the communities to which they devoted their professional lives
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".
1. Red oak-linden (basswood) mesic forest— This community was described by Weaver (1965, p. 14-17) as the most mesophytic forest in Nebraska. It extends from draws to north slopes and is one of the best-developed forest types at the edge of the vast grasslands of the continental interior. Ironwood or hop hornbeam (Ostrya virginiana) is the dominant species of the shrub layer, but Virginia creeper and wild grape vines climb trees to give an aboreal shrub component. The Missouri Natural Areas Committee (1987) described a similar community as mesic upland forest. The Society of American Foresters (1980) did not list or describe this type, but Braun (1950, p. 234) interpreted it as comparable to the red oak-sugar maple-basswood community in Pennsylvania and in the Mississippi Valley section of the oak-hickory region in Nebraska.Westveld (1939, pgs. 46, 51, 67-72, 77, 86, 114-117, 267, 268) recognized the red oak-basswood-white ash forest type for the New England white pine and central hardwood regions as well as for the mid-Atlanic oak region. Thus it seemed likely that the red oak-basswood mesophytic forest which occurs at the western-most edge of the immense eastern deciduous forest formations and the eastern origins of the vast interior grasslands is a variant of SAF 26 (Sugar Maple-Basswood) which was described as grading into other cover types throughout the deciduous forest zone.No obvious FRES or Kuchler designation, but basswood is a dominant of K-90 (Maple-Basswood Forest) to which it bears some taxonomic kin based on the Braun interpretation. Schramm State Park, Sarpy Cass County, Nebraska.August, estival aspect.
2. Basswood or American linden Forest- This is a "pure" basswood (Tilia americana) form of the Sugar Maple-Basswood Forest that was recognized as forest region 8 by Braun (1950, P. 327-336) or Maple-Basswood Association or Maple-Basswood Forest Type (Braun, 1950, see index therein). Braun (1950, p. 328) remarked that some authorities regarded the Maple-Basswood Region as a western continuation (faciation in her Clementsian usage) of the Beech-Maple Association, but she rejected this based on its geologic age of origin. It is a pure basswood variant of SAF 26 (Sugar Maple-Basswood). Eyre (1980, p. 31-32) concluded that the basswood cover was the most variable component such that basswood was the key species of this forest cover type. Wenger (1984, p. 3) rated sugar maple as Very Tolerant and basswood as Tolerant, however, basswood grows faster than sugar maple and regenerates asexually through stump sprouts which gives it an advantage over sugar maple (Eyre, 1980, p. 32).
This is an interior view of the basswood dunes forest that develop inside the dune complex along the shores of Lake Michigan. The remarkably diverse understory is not clear in this slide taken in the winter phase, but the arboreal-dwelling shrub or liana layer is conspicuous. It consist of bittersweet (Celastrus scandens) wild grape (Vitis cordifolia), and poison ivy (Rhus toxicodendron= R. radicans= Toxicodendron radicans). This forest community was described by Cowles (1899, ps. 361-367) in the first recorded study of plant succession in the United States. Sugar maple and American beech are scarse associates in this stand. Virginia chokecherry (Prunus virginiana) and red osier dogwood (Cornus stolonifera) dominate the tall shrub layer. Eastern witch hazel (Hamamelis virginiana) and hop tree (Ptelea trifolianta) are other common shrubs. Cowles (1899, p. 362) regarded starry false solomon's seal (Smilacina stellata) as the only characteristic herb. Canada wildrye is the dominant grass but is found only in small openings. Hibernal aspect.
Indiana Dunes State Park, Porter County, Indiana. Hibernal aspect. FRES No. 18 (Maple-Beech-Birch Forest Ecosystem), K-90 (Maple-Basswood). SAF 26 (Sugar Maple-Basswood). Maple-Basswood Series of Brown et al. (1998).
3. This is an interior view of the basswood dunes forest that develop inside the dune complex along the shores of Lake Michigan. The remarkably diverse understory is not clear in this slide taken in the winter phase, but the arboreal-dwelling shrub or liana layer is conspicuous. It consist of bittersweet (Celastrus scandens) wild grape (Vitis cordifolia), and poison ivy (Rhus toxicodendron= R. radicans= Toxicodendron radicans). This forest community was described by Cowles (1899, ps. 361-367) in the first recorded study of plant succession in the United States. Sugar maple and American beech are scarse associates in this stand. Virginia chokecherry (Prunus virginiana) and red osier dogwood (Cornus stolonifera) dominate the tall shrub layer. Eastern witch hazel (Hamamelis virginiana) and hop tree (Ptelea trifolianta) are other common shrubs. Cowles (1899, p. 362) regarded starry false solomon's seal (Smilacina stellata) as the only characteristic herb. Canada wildrye is the dominant grass but is found only in small openings. Hibernal aspect.
Indiana Dunes State Park, Porter County, Indiana. Hibernal aspect. FRES No. 18 (Maple-Beech-Birch Forest Ecosystem), K-90 (Maple-Basswood). SAF 26 (Sugar Maple-Basswood). Maple-Basswood Series of Brown et al. (1998).
4. Dim-lite understory of basswood dune forest- The herb here is true Solomon's seal (Polygonatum biflorum). The three young saplings are basswood with the characteristic young bark of this species. Reproduction was by seed. Indiana Dunes National Lakeshore, Porter County, Indiana. Autumnal aspect, October.
5. Dark interior of a basswood-dominated northern hardwood forest- Interior view of basswood dune forest showing the more common asexual reproduction of this Tolerant-rated species. On this Lake Michigan sand dune xerosere basswood enters shortly after eastern cottonwood (Populus monilifera= Q. deltoides) and it is an associate with black oak (Quercus coccinea tinctoria= Q. velutina; could even be hybrids of Q. rubra X Q. velutina) and, infrequently, jack pine (Pinus banksiana). Cowles (1899, p. 365) reported that sugar maple, American beech, and eastern hemlock "produce the densest shade and cause the extermination of the basswood and its associates". This would prove that basswood is sublicmax to the other three which were rated Very Tolerant (Wenger, 1984, p. 2-3). More on this below. Autumnal aspect. Indiana Dunes National Lakeshore, Porter County, Indiana. October. FRES No. 18 (Maple-Beech-Birch Forest Ecosystem), K-90 (Maple-Basswood). Representative of the Maple-Basswood foraest Region and Maple-Basswood Association of Braun (1950, p. 36, 327-336, 448, 524, 527).
6. Basswood growth form and asexual reproduction- This basswood specimen is on a north slope as an associate with a southern mixed hardwood forest including sugar maple, black walnut, and American sycamore. It is a textbook example of vegetative reproduction which characterizes this species (Harlow et al., 1979, p. 421). Burns and Honkala, 1990, p. 787) explained that this stump or basal trunk sprouting "allows basswood to maintain itself in a stand with the more shade-tolerant maple despite the much larger numbers of sugar maple in the subcanopy". In the Sugar Maple-Basswood Cover Type (SAF 26) maple dominates both canopy and understory (Burns and Honkala, 1990, p. 786).
The understory in this vernal aspect of mesic woods includes bloodroot, trout lily or yellow dog-tooth violet, broadleaf waterleaf, rue anemone, false rue anemone, and mayapple. The bloodroot is conspicuous immediately in front of the trunk. Bluffs above Lost Creek, Ottawa County, Oklahoma. April.
7. Basswood or American linden- Leaves and inflorescences of Tilia americana.
8. American Beech-Sugar Maple Forest- This is interpreted as the climax hardwood forest of the Till Plains, southern portions of the Great Lake Section eastward to Ontario and south to the Western Mesophytic Forest (Braun, 1950, p. 305). The vegetation of this and the next photograph is representative of the Beech-Maple Forest Region and the Beech-Maple Association of Braun (1950, p. 36-37, 305-326, 532-533). It is in the Lake Michigan Dunes locality and, with eastern hemlock as the third dominant tree, was viewed as the climax of the lake dune complex by Cowels (1899, p. 365-367, 384-385). Cowles saw the area occupied by the developmental sequence of vegetation (what Clements called a dune xerosere) becoming progressively more mesophytic until its termination as the Beech-Maple-Hemlock Forest.
To Cowles the basswood-dominated forest that preceded the terminal forest was less mesic than the beech-maple-hemlock forest type. It was noted above that this classic paper by Henry Chandler Cowles was the first published study of plant sucession in North America and that it was the springboard for F.E. Clements grand theory of "dynamic plant ecology". In context of the Clementsian paradigm the basswood-dominated basswood-maple forest was subclimax to the beech-maple-eastern hemlock forest. However, Cowles did not consider specific habitats or forest sites within the Lake Michigan dune complex but viewed sand dunes as all having the same potential end point. At the Lake Michigan dunes and adjacent habitats that remain preserved the beech-sugar maple forest is restricted to alluvial terraces and river bottoms. At this location the dune sere(s) did not appear to progress beyond the basswood forest in which sugar maple and beech were relatively rare. Cowles (1899, p. 365) stated clearly that beech-sugar maple forest were "not frequent on old dunes at the south end of the lake" or well-developed in the dunes region compared to northeastward in Michigan.
It would seem that that basswood-dominated upland hardwood forest seen above (in the dune depressions and slopes) is climax for the xerosere of dunes, and that viewing the beech-sugar maple forests of alluvial sites as climax ignored the fact that two different, distinct habitats (= seres) were represtented. Basswood communities would be subclimax on bottomlands but climax on the upland forest site(s).
The example of the American Beech-Sugar Maple Association seen in this winter aspect still has some scattered representatives of the dominant species of earlier seral stages including basswood as an associate, white ash (Fraxinus americana), black oak, eastern cottonwood, and even white walnut or butternut (Juglans cinerea). Smaller trees or shrubs include sassafras (Sassafras officinale) in openings and edges and eastern hop-hornbeam (Ostrya virginiana) even in deep shade plus the understory species seen in the basswood-dominated communities. The white snag is an American beech as are the trees with pale bark. The large, straight, dark-colored trunks in the center are sugar maple. The smaller trees that retained their leaves are young sugar maples indicating reproduction in shade as is the case for beech (the slender trees in the foreground with light-colored bark).
This is a bottomland forest in the floodplain of the Little Calumet River. Indiana Dunes State Park, Porter County, Indiana. Winter aspect. FRES No. 18 (Maple-Beech-Birch Forest Ecosystem), K-93 (Beech-Maple Forest), SAF 60 (Beech-Sugar Maple). Beech-Maple Series of Brown et al. (1998).
9. American Beech-Sugar Maple Bottomland Forest- This is a representative of the climax Beech-Maple Forest Association and the Beech-Maple Forest Region of Braun (1950, ps. 36, 305-326, 532-533). The understory layers are similar to those of the previous slide except for more mesic species of herbs such as large-flowered trillium (Trillium grandiflorum), jack-in-the-pulpit or Indian turnip (Arisaema triphyllum), and beechdrops or cancer-root (Epiphegus virginiana) (Cowles, 1899, p. 365). Basswood is the major associate.
Climax bottomland (floodplain) Beech-Sugar Maple Forest on banks of Little Calumet River. Indiana Dunes state Park, Porter County, Indiana. Hibernal aspect. FRES No. 18 (Maple-Beech-Birch Forest Ecosystem), K-93 (Beech-Maple Forest), SAF 60 (Beech-Sugar Maple). Beech-Maple Series of Brown et al. (1998).
In the Clementsian monoclimax theory there is a regional-scale climax determined by climate of that region or zone. As such this is climatic climax or, as synonyms, regional climax or just plain climax where the term climax is derived from climate. Given that climax and formation were used by Clements as synonyms, climatic climax= regional climax= formation and, later in Bioecology (Clements and Shelford, 1939), biome. This was monoclimax theory (ie. all above synonyms were synonymous with monoclimax). This was the conceptual framework on which Braun (1950) hung her Clementsian associations of the Deciduous Forest Formation.
According to monoclimax perspective the climatic or regional climax is that which would theoretically exist if the terrain of a region was geologically eroded down to a level upland (ie. hills or mountains worn down and stream drainages filled in such that a peneplane prevailed) (Spurr and Barnes, 1980, p. 413). This would result in a relatively uniform mesic upland according to the prevailing geologic theories upon which Clements based his view of monoclimax. From the monoclimax perspective it seemed most logical to view the regional climax for the locations seen in these photographs as the basswood-dominated upland forest with the beech-sugar maple bottomland forest as post-climax to the basswood forest.
In the shorter time scale of the polyclimax theory, the alternative conceptual view that was proposed by Clements' close friend Arthur Tansley, there are several potential climaxes within the spatial scale of the region in the time period before geologic leveling to an average upland plain. Within a region there are smaller habitats which because of local or area variations in soil, slope, aspect, fire or flooding regime (largely functions of climate), etc. there are physiographic, edaphic, pyric, zootic climaxes that override the influence of regional climate. Polyclimax theory allows interpretation of the basswood forest as climatic climax (beacause it is the mesic upland forest) and beech-maple forest as topographic or edaphic climax.
The third major conceptual view of climax is the climax pattern theory advanced by Robert H. Whittaker (1953). This composite perspective incoroporated parts of both mono- and polyclimax theories besides adding population interpretations that seemed modified from the individualistic theory of plant communities advanced by Henry Allen Gleason (1926). Climax pattern theory would also allow both of these forest communities to be interpreted as climax forest types. With all three climax theories, the basswood and beech-sugar maple forest are potential natural vegetation, by whatever designation they bear.
Also by any ecological status these forest are quite vulnerable to damage by grazing and browsing and forest regeneration can be retarded or prevented by improper grazing management. Species of timber-producing trees are primarily of the phanerophyte life (= growth) form developed by Raunkiaer (1934). Phanerophytes (from Greek phaneros, meaning "visible") are those plants having surviving buds or shoot apices borne on shoots projecting into the air (well above ground level). They include evergreen species both with and without bud coverings and deciduous woody species with bud coverings. The physical location and "presentation" of the apical tissue well within "easy reach" of browsing animals, fires, wind, etc. makes phanerophytes the most apt to be damaged by these agents of defoliation. Like the army gaining tactical advantage of the hill or ridge phanerophytes have the competitive advantage of occupying the "high ground" and fixing light while denying it to the understory species or slower-growing, shade-intolerant woody plants. This "high ground" advantage carries the cost of putting phanerophytes more "in harm's way", and also at a competitive disadvantage with those species having any of the other growth forms as for example cryptophytes (krypos is Greek for "hidden") like many of the perennial grasses which have rhizomes and root crowns at or below the soil surface. Therophytes (theros is Greek for "summer") are annuals or ephemerals which are the most tolerant of all life forms to defoliation because they survive as relatively small, unpalatable, and neigh-on-to-indestructable seeds. This is why overburning and overgrazing ultimately result in a preponderance of annual grasses and herbs in abused plant communities and why grasslands and savannas are maintained under proper burning management.
Phanerophytes of both woody angiosperm and gymnosperm species have meristematic tissue, especially apical meristems, that are readily accessible to browsing animals until most of these tissues grow beyond teeth, tongue, lips, hooves, etc. Even at matuirity the bark and cambium of woody plants remain exposed to herbivores like beavers, porcupines, and elk. Conifers, however, generally are much less palatable— for whatever interesting plant defense mechanisms are involved —than angiosperm trees and shrubs. Coniferous forests also typically are more open with understories which produce grass and browsable shrubs that are relatively more palatable than dominant conifer species. Finally, the naked seeds of conifers are less nutritions and palatable than the fruits of angiosperms. The nut pines are an exception, but a mental comparison of acorns, hickory nuts, walnuts or even maple samaras to the seeds of ponderosa pine or redwood proves the general condition.
Nutritional attractiveness of fruits is an evolutionary adaptation for propagule dissemination by animal dispersal (epizoochory), but what happens when there is "too much of a good thing" as by introduction of too many efficient epizoochores (eg. too many acorn-eating, rooting hogs in the woods)? Any observant woodsman knows how readily livestock, especially hogs, fatten on forest mast. This was discussed in historical perspective by Towne and Wentworth (1950, ps. 104-112) who indicated specifically the role of free-ranging hogs in destruction of native bamboo canebrakes.There is probably no mast more palatable to swine than beechnuts. Steyermark (1963, p. 528) discussed use of beech in Missouri and reported that beechnuts "are a favorite food of hogs in those areas where open range is permitted". Burns and Honkala, 1990, p. 330) reported that all kinds of animals, including black bear and fox, ate beechnuts and that beech was "the only nut producer in the northern hardwood type". Obviously sexual reproduction of the dominant species in the American Beech-Sugar Maple Association can be impacted adversely by improper numbers and kind of animals.
This includes wildlife the same as livestock. In commenting on beech-dominated northern hardwood forest as habitat for wild turkey Wunz and Pack in Dickson (1992, ps. 235-236) stated that shrubs which are desirable for turkey have been reduced and even eliminated due to overbrowsing by white-tailed deer. They noted further that most understory species in this forest type are palatable and prone to damage by deer. Burns and Honkala (1990, p. 330) reported that American beech was seldom utilized heavily by white-tailed deer and that when other tree species were present beech was "usually nipped only sparingly". Beech often reproduces asexually by root suckering, especially on south slopes (Burns and Honkala, 1990, p. 327-328), so it can persist with properly managed herbivores. Again, this includes management of wildlife species. Bag limits to control (reduce and keep consistent with grazing capacity) deer numbers are as critical as is stocking rate with cattle or range hogs.
One of the best and longest-term studies on the role of native and domestic herbivores on mixed deciduous forest ecosystems is that reported by Tubbs (1968) and Putman (1986).
Multiple use management of northern hardwood forests to include browse and forage for range animals is a valid and desirable goal if— as is always the case —management is well-planned and -conducted. Even hogs (eg. feral "Russian wild boar" as a game animal) can be safely included in forest management if, above all else, proper animal numbers are maintained so as not to interfere with forest regeneration. Sometimes that is a "big if". Conscientious stock-growers realize and manage according to the truth given by Spurr and Barnes (1980, p. 360):
"Around the world, grazing by livestock has probably been more important than any other factor in reducing the productive capacity of uncultivated land".
Livestock consumption of woody forest plants, even seemingly relatively unpalatable species such as Virginia creeper or posion ivy, and even by cattle is self-evident when these plant species recover following removal of livestock (again, even beef cattle which do not prefer shrubs). In recent years leaders in the livestock industries have become extremely "pro-active" in identifying and highlighting examples of faithful stewardship. The Environmental Stewardship Program of the National Cattlemen's Beef Association is a sterling example and makes one proud to be counted among the membership. This must be an unending effort by all involved.
10. Mast of the Oak-Hickory Forest- Pignut or bitternut hickory (Carya cordiformis), hazelnut (Corylus americana), Ohio buckeye (Aesculus glabra), black walnut (Juglans nigra), bur oak (Quercus macrocarpa), and northern red oak (Q. rubra).
11. About as dense and dark as it gets- High noon in early summer in the interior of an oak-hickory forest in which American beech and sugar maple are the major associate species. In the first of these three photographs pignut hickory dominated a stand of mature trees on a north slope. The second photograph featured a second-growth stand dominated by American beech with pignut hickory as associate species on a northeast slope. The third slide showed dominance of beech in this stand (pignut hickory represented by one tree in right background). The second and third slides presented the very liited understorey which was comprised mostly of regenerating beech. This demonstrated the Very Tolerant tolerance rating of this species. In fact, presence of several age classes of beech attested to this feature.
Extent of shade on the forest floor at mid-day (1230 Central Standard Time) in early summer portrayed (clearly though darkly) the phenomenon of sunflecks and and the resultant extremely sparse layer of range vegetation on this shaded forest floor.
July. Buffalo National River, Newton County, Arkansas.
12. American beech, and nothin' else- A northeast slope above floodplain of the Buffalo River was naturally stocked by the single species, American beech. This was an example of a forest consociation. In the first of these two slides there was only one representative of another tree species. Can you find it? Hint: it is a pignut hickory. Note the different age classes of beech present in these two "photo-plolts". Viewers should also take not of relative area of the forest floor as to: 1) proportion of shade and 2) absence of understorey species other than beech. These photographs showed the maximum surface area of the ground receiving sunlight in early summer because pictures were taken at mid-day (1230-1245 hours Central Standard Time) when shadows cast by trees was at a minimum. The portion of shaded vs. sunlite ground surface also presented the concept of constanting changing patches of light caused by changing position of Earth relative to its sun, cloudiness (not shown on this cloudless day), and wind-caused leaf movement.
The scant plant cover and density at lower layers of this forest vegetation was largely due to the dense shade cast by beech (the specific epithet, grandifolia, was chosen most appropriately). It was likely however, that grazing/browsing by livestock in the not-too-distant past was also a factor in lack of understorey development. This steep hillside was now part of Buffalo National River, but it had previously privately owned land that was located immediately above an old barn (of sorts) and "cowpens". Any halfway knowledgable forest or range "detective" would have to assume that even a slope of this steepness had received relatively heavy stocking of cattle. Also, this area was some of the last legal open range (land open to the public to run livestock on and therefore subjected to free-roaming livestock) which included free-ranging, privately owned hogs. Swine are potentially the single most destructive species of range livestock on deciduous forest such as oak-hickory and oak-pine cover types. There was no denying the high probability that cattle and hogs had likely impacted this tract of forest in recent history of, say, 15-25 years ago. Nonetheless, much of the absence of understorey development was due to conditions of exteme shade.
July. Buffalo National River, Newton County, Arkansas.
13. Sign post (or "fools names in public places")- The trunk of an old American beech bore names and other graffiti left by vulgar, clueless scribes (probably urban and rural) who could not resist the temptation to use beech's characteristically smooth bark as sylvan space on which to "leave their mark" The mark left by literal sons of bitches (Canis familaris, C. latrans) quickly dries and, if not too frequently left, leaves little impact on the face of Mother Nature. By contrast, the heavy hand of vain-glorious, ego-driven, illbred, human SOBs bears a longer-lasting imprint of visitors to public property who violate the first rule of the woods, Leave a Clean Camp. Besides, unlike Daniel Boone, these self-centered wood carvers kilt no b'ars under thishere beech. Any claw marks left by the once native black bear (Ursus americanus) would by contrast be most welcome in this designated wilderness administered by the National Park Service.
Desecrationof public property aside, the identifying smooth gray bark and dense shade cast by American beech was presented in this Kodak moment on a steep north slope dominated by beech in the Ozark Plateau.
Another feature of American beech is root sprouting, development of secondary shoots from roots of mature and even uninjured beech trees. Most of the beech shoots in foreground of this photograph arose as asexual (vegetative) reproduction rather than as sexual reproduction from this tree, the bark of which that bore inscriptions from self-appointed, wood-carver scribes. More examples of root suckering (sprouting) were presented farther below.
July. Buffalo National River, Newton County, Arkansas.
14. A steep, beech-shaded slope- This steep, north slope was dominated by American beech underwhich shade-adapted plant species comprised some layers of forest vegetation. Root sprouts or secondary shoots (introduced in the preceding slide) and beech seedlings made beech the most abundant plant species at various micro-locations, but there were a few other understorey species including poison ivy, Virginia creeper, Christmas fern (Polystichum acrostichoides), and rolled sedge (Carex convoluta). The mature tree and two smaller trees closest to it on the right were beech as were most of the seedlings and small saplings, almost all of the latter of which were root sprouts of the adult tree.
July. Buffalo National River, Newton County, Arkansas.
15. Hard to see but instructive- Trunk of the largest American beech shown in the preceding photograph was shown in more detail in these two slides. One distinctive feature of beech--especially older, larger trees--is the self-exposed roots which in normal growth commonly protrude above the ground surface.This growth characteristic results in a fluted basal tree trunk.
Also presented in these photographs were the lower layers of forest vegetation--sparse though they were--that developed in the dense shade of a stand of beech. Viewers were again reminded that this photograph was taken at noon time (1230-1245 hours Central Standard Time) when light penetration to the forest floor was theoretically greatest overall (on average). Some plants of rolled caric sedge were visible in the second slide.
The phenomenon of sunflecks was presented here,, but shown to better advantage in the next slide. Another phenomenon displayed in the first of these two slides was that of geotropism, the directional movement (and subsequent growth) of a plant to gravity. This old beech was leaning so as to remain upright against the pull of gravity as exerted on this steep hillside (ie. a plant response to the stimulus of gravitational pull). There was also greater accretion of wood in the trunk on its uphill side in order to balance the entire shoot (bole and crown) of this beech which was large by standards of the Ozark Plateau, a marginal habitat for one of the most mesic of North American hardwood (angiosperm) tree species.
July. Buffalo National River, Newton County, Arkansas.
16. Things got hot (but they're cool now)- The personality of this beech attested to hot fire(s) in the past. This scar extended over eight feet up the bole of this second-growth specimen and penetrated through to the heartwood. Most trees survive this invasion (at least initially) unless such injury allows entry of pathogens that may later kill the tree, directly or indirectly. Heartwood and much of the sapwood is dead tissue anyway so that loss of such wood has no physiological impact on the plant. Instead the tree is weakened by loss of some support provided by the trunk. This frequently results in toppling of the tree when it is subjected to high winds: blowdown when the trunk is snapped, or, even, twisted off. Examples of such blowdown or windthrow (and the consequent forest gaps) were presented later in this section.
For now this beeech was still a "member in good standing" of this forest community. Much of the beech reproduction (which made up most of the regeneration shown here) was asexual in form of root sprouting (suckering). Throughout this section emphasis was frequently placed on the phenomenon of secondary shoot production by root sprouting in American beech. Some of the smaller trees presented here were seedlings showing that both sexual and asexual reproduction was successful in this forest. This was in spite--or perhaps because--of fire which may have initiated beech suckering.
Fire(s) that burnt this beech and its neighbors undoubtedly had influences on neighboring plants, for good and bad depending on species.
Lost Valley, Buffalo National River. Newton County, Arkansas. July, estival aspect.
17. Memories of hotter times- An American beech sports a long and deep fire scar that bears testimony of a once-upon-a-hot-time in these Boston Mountains woods. Like the example presented in the preceding photograph, the fire scar of this second beech had burnt through to the heartwood along entire height of the pyric injury. In fact, in both of these cases flames inside the trunk actually burned higher up inside the bole than on the outside. Also, these trees were healing around the injured area so that the scar was simultaneously "growing" as the tree grew in heighrt and girth and also healing over as replacement growth enveloped the injury site.
The thin bark and big, protruding roots of beech make it one of the most susceptible hardwoods to fire (Fowells, 1965, p. 176; Burns and Honkala, 1990, p. 329). Thin bark also makes beech prone to sunscald, especially when trees in dense forest (hence protected from damage from sun's rays) are suddently exposed to brighter or even full-sun following logging. This species is also vulnerable to mechanical injury from logging and prunibng as well as damage by insects with piercing-sucking mouthparts (bugs) and diseases in general.(Burns and Honkala, 1990, p. 329).
As demonstrated by this and the preceding example some individuals of American beech can live with extensive fire injury as long as additional strrains from wind and gravity and stresses do not exceed physical strength and disease pathogens cannot gain entry through a compromised physical barrier of bark and associated tissues. It was not known if fire was a factor involved in root suckering.
Lost Valley, Buffalo National River. Newton County, Arkansas. July, estival aspect.
18. Innards of a botanical "island"- Composition and structure of an Ozark forest dominated by second-growth American beech. Isolated forest communities of beech-sugar maple occassionally develop in more favorable habitats of the regional oak-hickory forest (ie. isolated communities of the beech-sugar maple association within the surrounding oak-hickory association).Forest vegetation in these two photographs represented the interior of an American beech-dominated variant of the white oak-northern red oak-pignut hickory community of more mesic environments such as this one in the Boston Mountains of the Ozark Plateau region. The two photographs were horizontal and vertical views of the same stand to better represent species make-up and forest structure.
While beech requires more mesic forest sites than its co-dominants in this forest (white oak, northern red oak, pignut hickory) it also require better drained soils. Beech is one of the most flood intolerant species of all North American trees, especially flooding durnig the growing season (Burns and honkala, 1990, p. 329).
Almost all of tree regeneration in this stand was beech and not that of white oak, the major co-dominant, or sweet gum, a locally abundant associate that is a seral species sometimes persisting into advanced successional stages. This was also the case for some of the other stands presented below.
This forest understorey was comprised of both herbaceous and woody species, including beech seedlings and root sprouts as discussed above. The most abundant, though certainly not of great density or foliar cover, herbaceous species overall was hairy wood brome. In locally miacrosites the herb with most cover was broad beech fern. mmon.
Lost Valley, Buffalo National River. Newton County, Arkansas. July, estival aspect. FRES No. 15 (Oak-Hickory Forest and Woodland Ecosystem). K-91 (Oak-Hickory Forest). Mixed mesophytic form of the oak-hickory forest with American beech as defining/distinguishing species and in association with sugar and red maple designated this as a isolated unit of a variant of SAF 60 (Beech-Sugar Maple) rather than as a variant of SAF 52 (White Oak-Black Oak-Northern Red Oak). Likewise, isolated unit of Beech-Maple Series 122.13, Northeastern Deciduous Forest 122.1 of Brown et al., 1998, p. 37). Boston Mountains- Upper Boston Mountains 38a (Woods et al., 2004).
19. A study in American beech (Fagus grandifolia)- A mature beech at old-age including some sucker shoots arising from surface roots. Leaves and the smooth, gray bark of beech were also presented in this composite shot. Buffalo National River. Newton County, Arkansas. July.
20. Shady details- Close-up photographs of basal trunk of the American beech presented in the preceding photograph. The photograph presented details of beech bark and (in front of trunk) a secondary shoot arising from one of the upper roots that was naturally protruding above ground surface. Second photograph showed this entire root sucker.
The thin, smooth bark of American beech makes it very susceptible to fire injury and sunscald (Burns and Honkala, 1990, p. 329). Sunscald refers to the condition of "localized injury to bark and cambium caused by a sudden increase in exposure of a stem or branch to intense sunlight (insolation) and high temperatures" (Helms, 1998). Certain smooth, thin-barked tree, including both beech and sugar maple, are also susceptible to winter sunscale which can develop on the side of trunks and limbs that are exposed to warmer temperatures and brighter light of winter afternoons.
Buffalo National River. Newton County, Arkansas. July.
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21. Leaves of American beech #1-Leaves and twig on the root sucker of beech introduced in the preceding two slides. Northeast slope above Boxley Valley in Boston Mountains. Phenomena of tolerance, shade leaves, and sunflecks was explained in the two-slide set presented immediately below.
Buffalo National River. Newton County, Arkansas. July.
22. Leaves of American beech #2- Another (the second) example of a beech root sucker. This specimen was growing in the terrace (broad stream bank) of Clark Creek that drains into Buffalo River. Both this and the previous example of beech leaves also showed the extremely shady conditions produced by the dense foliage of American beech and high this Very Tolerant species can grow and have successful vegetative (asexual) reproduction in the dim microenvironment beneath its own dense foliage.
These two photographs (and the two photographs shown immediately above) were taken using natural light at mid-day (1245 hours Central Standard Time). This photographer had to wait until a shaft of light from the appropriate direction struck the leaves of these root sprouts. This was for a brief period lasting no more than a quarter hour. Most likely there were other such brief periods when the orientation of Earth to Sun permitted streams of light to strike these leaves. This is the phenomenon of sunflecks, several examples of which were presented in this section. Obviously these-more-often-shaded-than-sunstruck beech leaves were, on average, more sinks than sources of photosynthate. These lower leaves almost assuredly had to be supported by leaves in the crown which functioned as photosynthate sources for these energy and nutrient-dependant organs.
Leaves on these beech root sprouts (secondary shoots arising from near-surface or even protruding roots) were example of shade leaves, those which due to their position in shaded environments are larger and thinner than co-hort sun leaves that are in environments which receive full-sun light (even if on the same tree).
Buffalo National River. Newton County, Arkansas. July.
Directions: the rest of the example of Ozark forest dominated by American beech was included in Oak-Hickory Forest-I.
23. Fruits and leaves of American Beech.
24. Sugar maple (Acer saccharum)- Leaves and fruit (paired winged schizocarps) of the co-dominant of the beech-maple forest cover type. This example was from a north slope bluff above a stream in the oak-hickory forest of the Ozark Plateau. Early pioneers in southwest Missouri, northeastern Oklahoma, and northwest Arkansas tapped sugar maples for syrup in the same way as in New England. Ottawa County, Oklahoma. August.
25. 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).
26. A real bundle- Cluster of schizocarps of sugar maple in mid-summer. This photograph presented better depth-of-field for abit more detail than that afforded immediately above. Ottawa County, Oklahoma. Late July.
27 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.
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