Oak-Hickory Forests-IB

Forest Range Types of Eastern North America

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 98^th 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:

Mixed Mesophytic Forest Region,
Western Mesophytic Forest Region,
Oak-Hickory Forest Region,
Oak-Chestnut Forest Region,
Oak Pine Forest Region,
Southeastern Evergreen Forest Region,
Beech-Maple Forest Region,
Maple-Basswood Forest Region, and
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.

Historical Footnote and Editorial

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".

Bur Oak (Quercus macrocarpa) Forest

Bur oak as a forest cover type (SAF 42; Eyre, 1980, ps. 39-40, 236) is the most northward and westward of the eastern and central continental tree oaks. Bur oak comprises the only oak forest cover type in more northern portions of the Central Lowlands and Great Plains physiographic provinces. Bur oak is extremely tolerant of drought and fire and forms forests, groves and savannahs within (and within) the central grasslands of North America from the eastern edge of the Prairie Peninsula (Transeau, 1935) through to the Black Hills (Eyre, 1980, p. 39). Bur oak is to this vast region what post oak and blackjack oak are in the south (eg. Cross Timbers). These two forest range types meet near northern reaaches of the Flint Hills Region.

Presented in this section was an example of the bur oak forest cover type (SAF 42) found on a north slope and outward to a ridge top in the Nebraska Sandhills. This was about as dry (least mesic) an environment as bur oak is adapted to, at least to the extent of forming forest communities. This example was a forest and not a woodland or savanna although at its outer edges it did form small groves with tree density and understorey more suggestive, or even typical, of woodland. This contiguous bur oak-dominated community (both forest and grove phases, or two communities if so interpreted) was the climax (ptential natural) range vegetation on this sere except where frequent, close, mechanical mowing had converted the native herbaceous understorey to a manmade one made up of Eurasian perennial grass species adapted to such intensity and frequency of defoliation. Examples of both native and naturalized herbaceous layers were presented following a brief section that introduced the foliage and fruit features of bur oak.

This relict stand of bur oak forest had developed on what was at this time the Valentine, Nebraska city park (and almost any city park says it all). This forest range vegetation occupied both upland, including and especially a mesic north-slope, and bottomland site. Vegetation on all but the north-slope was highly modified by yard-mowing, manicure-it urban man (even in this over-whelmingly rural region). The natural herbaceous understorey of the upland phase was Canada wildrye (Elymus canadensis) except on north-slope upland forest range where the dominant herb was—as on the bottomland phase—long-beak(ed) or Sprengel’s sedge (Carex sprengelii). It was likely that there was also some bristleleaf or ebony sedge (C. eburnea) was growing in association with long-beak sedge, but C. eburnea could not be positively identified given absence of inflorescences. Under frequent, close mowing Kentucky bluegrass (Poa pratensis) dominated the lowland understorey. With less frequent mowing smooth brome (Bromus inermis) dominated both bottomland and upland phases.

Both of these introduced Eurasian grasses have naturalized widely and under a farmer (vs. forester or rangeman) frame of mind, and management consistent therewith, the native grasses and sedges were crowded out by aggressive, highly competitive agronomic forages. The timeless story since Cain and Abel. The farmer (cornhusker in the Cornhusker State) again won out over the pastoralist.

137. Big tree on the prairie- Beautiful and massive specimen of bur oak that made its home in the floodplain of the Bosque River in the Western Cross Timbers of northcentral Texas. Bur oak is obviously a minor member--especially when compared to the dominant post and blackjack oaks--of the scattered forest and woodland communities in southern portions of the tallgrass prairie region. In more northernly parts of this vegetational realm bur oaks replace blackjack and even post oak as the dominant oak. In these northern parts of the Prairie Peninsula and tallgrass-true prairie region bur oak would be second--if that--only to eastern cottonwood as a dominant tree both on grassland and isolated forest communities such as gallary forests. Bur oak is the most widely distributed of all the oak species that have the role of hardwood dominant across the North American central prairies (McGregor et al., 1977, ps. 39-41). Post oak and blackjack oak barely extend northward to Iowa whereas bur oak extends to Ontario.

Bur oak forms forests, woodlands, and groves (distinguished by tree density, extent of canopy cover, and size of stand resulting in varying degrees of understorey development) in more northern areas of North America as in the Nebraska Sandhills, an example of which was used for photographs and corresponding descriptions and explanations in this section.

Hamilton County, Texas. July.

138. Bur(r) or mossy cup oak (Quercus macrocarpa)- Young leaves and catkins of the dominant oak of the northern tallgrass, true, and mixed prairies northward from central Kansas. Bur oak can be interpreted as the northern ecological equivalent of post and blackjack oaks as the aboreal dominant of the grassland-deciduous forest ecotone (Vankat, 1979, p. 221). This species produces the largest acorns of any oak in North America and it is the oak of the famous oak groves and savannas of the northern grasslands (Peattie, 1938). Seedlings rapidly send their tap roots deep into the fertile prairie soils and become quickly established after germination (Weaver, 1968, ps. 135-139). This genetic adaptation to drought combined with the species’ thick fire resistant bark (Allen, 1967, p. 15) make it admirably suited to drought- and fire-prone prairies. It’s range extends far south of it’s region of dominance into central Texas where it sometimes dominates bottomland savannas.

Hamilton County, Texas, April.

139. Leaves and fruit of buroak- Burr oak (either one or two "rs" are used) is regarded as having the largest acorn of any Quercus species in North America. Like other white oak species buroak bears fruit every year (versus a two-year cycle) in the red or black oaks. The combination of large acorns and production each year makes this species one of the most valuable producers of mast in the eastern deciduous forest (ie. the eastern part of North America).

Burroak is also known as mossy-cup oak, both common names in reference to the conspicuous tapered tips of the scales of the cup which present a fringe-like appearance. The geographic range of. Q. macrocarpa extends from eastern Canada (New Brunswick and Quebec) to Texas.

Hamilton County, Texas. September.

140. Unusual leaf arrangement in bur oak- Bur oak has a unique arrangement of leaves along its leaders. Leaves grow in dense clusters or whorls at intervals along young branches (leaders) with one of these clusters (complete with the current year's acorns) on each of several internodes extending back toward the trunk until older internodes cease to produce such clusters. Two such leaf and acorn clusters on one leader were shown in this photograph. These were obviously the two youngest internodes which showed the last two year's growth of this shoot (one internode being produced each growing season).

Erath County, Texas. Late September; approaching fruit-ripe stage of phenology.

141.. Clusters of leaves (and acorns) in bur oak- Two clusters or whorls of leaves and acorns in bur oak. The first photograph presented a whorl from a lengthwise view whereas the second photograph presented more of an oblique and semiend-on view of the second whorl. Bur oak concentrates its leaves in large clusters infrequently along its branches (one cluster per internode) whereas most oak species produce individual leaves and some secondary (usually short) shoots off of young branches (= leaders or shoots) at more frequent intervals along their internodes.

Erath County, Texas. Late September; approaching fruit-ripe stage of phenology.

142. Clustered at the end- End-on views of two different clusters or whorls (at progressively closer distance) of leaves in bur oak. This is a unique and eye-catching arrange of foliage and fruit in a Quercus species especially well-adapted to drought and fire. Bur oaks grow at variuos densities ranging from isolated individual trees to small groves to dense forests (see rest of section immediately below). Function of this unique arrangement (pattern) of leaves in bur oak was unknown to this author.

Erath County, Texas. Late September; approaching fruit-ripe stage of phenology.

Technical Note: The following sequence of photographs of the Bur Oak forest cover type (SAF 42) was taken in early summer (late-June). Two aspects were presented and described: 1) north-slope and 2) hilltop. These represented two distinct aspect-based bur oak forest communities even though both were: 1) dominated by bur oak, 2) the same cover (dominance) type, and 3) upland forest. Both aspect-determined bur oak communities were photographed at the same time (about 0730 to 100 hours Central Standard Time). This time of day was most advantageous for pphotographing the north-slope forest which, having a general northeast orientation (hillside alignment), received most light in the understorey (maximum land surface area exposed to full-sun lighting; greatest understorey coverage of greatest light intensity) in early to mid-morning. Obviously time of daylight hours (excepting very early morning or late evening) was largely irrelevant for photographing vegetation of hilltop forest.

Relatively high density of adult bur oaks on the north-slope forest coupled with dense individual crowns of this large-leafed species resulted in one of the darkest understorey habitats ever seen by this photographer. Most of the understorey area (square footage, yardage, meterage, etc.) of the north-slope forest range received somewhere between half to three-fourths of an hour of direct light daily. During the remainder of daylight time plants--especially herbaceous species--were in relatively dense shade and obtained only indirect light. Herbaceous species in bur oak forest have to be some of the best adapted and most extreme examples of sciophytes (skiophyes) or sciaphlic (skiaphilic) plants, "shade-loving" or plants that have evolved to shade (shady habitats), in the eastern deciduous forest.

Viewers should realize that the shady (generally dark; poorly lite) images presented below, while of relatively poor viewing quality (compared to range types in other biomes), "caught" exactly normal light conditions as they existed, and at their brightest (time of day in which most light penetrated forest crown canopy to reach ground level). No artificial lighting was used. In other words, intensity and quality of light seen in photographs were those that the viewer himself would have experienced, the images that would have traveled through his cones, rods, and optic nerve, had he moved through this forest environment.One can but marvel at the adaptation of the herbaceous plants in bur oak forest range.

143. Sylvan scene in Nebraska Sandhills (Are you kiddin"?)- Send this as a postcard from the Nebraska Sandhills and those who deal in sterotypes will asert, "You're kidding me". Nope, the real thing.. Bur oak Sandhill forest on a north slope in early summer. Most of the trees in these two "dendrographic" photographs were bur oak (including the largest tree and the pole-size sampling in left front of the "big 'un"), but white or American elm (Ulmus americana) and green ash (Fraxinus pennsylvanica) were associates that were present (as in background of these two slides). (Incidentially the commerative specific epitthet pennsylvanica means literally "Penn's woods" [ in honor of the Quaker founder, William Penn] ; " sylva from the Latin and Greek roots is in reference to "wood" or "forest").

This was an old-growth stand of bur oak with the climax herbaceous species still dominating the understorey. This was clearly virgin range vegetation.

The graceful herbaceous understorey in these two "photo-plots" was almost exclusively made up of long-beak or Sprengel's sedge (Carex sprengelii). Canada wildrye (Elymus canadensis) was the associate herbaceous species overall though very little of this grass was present in forest range vegetation presented here. Eastern red cedar (Juniperus virginiana) had in absence of fire begun to encroach as an invader into this sylvan Eden.

Cherry County, Nebraska. Late June, estival aspect. FRES No. 15 (Oak-Hickory Forest and Woodland Ecosystem). No Kuchler unit for bur oak forest; closest was Bur Oak Savanna (unit 81 in Kuchler, 1964, unit 72 in .Garrison et al., 1977, including map). SAF 42 (Bur Oak). In Brown et al. (1998, p. 37) would be Quercus macrocarpa Association 122.11? (say 111) of Oak-Hickory Series 122.11 of Northeastern Deciduous Forest 122.1. Nebraska Sandhills-Sand Hills Ecoregion 44a (Chapman et al., 2001).

144. Appreciative of what it receives- Close-up "photo-quadrant" of local sward of long-beak or Sprengel's sedge presented in the first photograph of bur oak forest treated in this series. This is the very fleeting maximum intensity of light that these shoots will receive.Short duration of light from early morning rays on a north slope in Nebraska Sandhills.

Cherry County, Nebraska. Late June.

145. Forest and sunflecks- Nebraska Sandhills bur oak forest and shade-adapted herbaceous species. Light conditions of early morning, the major part of day during which light could reach ground level of this north-slope forest, provided a textbook illustration of the sunfleck phenomenon. In dense-canopy plant communities like forest (and even grassland swards) sunlight penetrates through foliage at varying lengths of time. The shortest of these light periods or bouts (time lengths or durations of light at whatever light intensity) which can last only a few seconds up to several minutes are known as sunflecks (Smith et al., 1989; Chazdon and Pearcy, 1991). The converse of sunflecks are shadeflecks which are shade fluctuations due to cloud cover between shaded spots and the sun.

In vegetation, such as that of a bur oak forest featured here, wind movement of leaves, travel of Earth relative to sun, and any cloud cover are responsible for the ever-changing state of light that penetrates to lower strata of the range plant community. The general condition or phenomenon of changing or dynamic light as to duration and related intensity or "fluctuation in irradiance" as it was described by Chazadon and Pearcy (1991, p. 760) is an all-important abiotic factor in growth and survival of plants in lower layers of range vegetation-- the understorey of this bur oak forest. Light dynamics interacts with other factors (abiotic and biotic) such as defoliation, precipitation, and, as in this north-slope forest, aspect. Dense shade produced by the large leaves and close interlocking crowns of bur oak on the aspect most shielded from sunlight resulted in severe conditions of light deficiency related stress for understorey plants in this bur oak forest.

Range plants in lower layers of this north-slope bur oak-dominated forest community were sciophytes (sciophytes), "shade-loving" species of the highest adaptation. There were a few, though extremely patchy or irregular, layers of woody plants below the forest canopy. These vegetational strata were made up primarily of regenerating bur oak (seedlings, saplings, and poles), American elm, green ash, and, least of all, eastern red cedar. This photographer did not see any shrub species. The herbaceous layer (which was also the ground layer) of this forest range was dominated mostly by long-beak or Sprengel's sedge with Virginia wildrye the associate species. The major--and about the only--forb was anise root (Osmorhiza longistylis).

This virgin range vegetation was a fine representation of old-growth bur oak forest (even if there were too many shadows to show it to best advantage).

146. A study in shadows- Closer-in photograph of the two big bur oaks and associated herbaceous layer introduced in the last slide (second slide of the preceding pair of photographs). This will be about all--and clearly the most (greatest intensity and longest duration of)--light that the understorey of this north slope bur oak forest will receive, and this was close to longest day of the year. Early morning and late evening were the major (about the only) times that sunlight could fall on the ground at this extreme north aspect.

The phenomenon of sunflecks as explained in the preceding caption was obvious.

Understorey was herbaceous, except for basal sprouts of bur oak (see below), and consisted primarily of long-beak sedge with some Canada wildrye. The only forb of note was anise root (Osmorhiza longistylis). This was virgin vegetation in structure and composition and in all layers; a good representation of climax bur oak forest range.

147. About as bright as it ever gets- The slant of earlier morning light on this north slope is just about as much photosynthetically active radiation as the understorey of this north-slope, Nebraska Sandhills bur oak forest ever gets.

These paired photographs presented an example of light dynamics in the understorey layer of this densely shaded forest range. The second of these two photographs was at a closer distance to trees, but the major difference in pattern of light and shade on the forest floor was due to changing radiation that occurred with passage of time. These photo-dynamics resulted from 1) variation due to the diurnal (day-and-night) cycle of light and 2) annual cycle due to travel of Earth on its yearly orbit around the sun. Sunflecks lasting only a few minutes or, perhaps more commonly, mere seconds (or fractions of seconds) are largely due to wind movement of leaves in the forest canopy. This rapid photo-dynamics--very short-term spots of alternating sun and shade--could not be captured in photographs or sequences photographs, but the prevalence of light dynamics, hence the concept of sunflecks, was represented photographically.

Trees and saplings in these slides were all bur oak. The herbaceous layer was mostly long-beak sedge with some Canada wildrye and, even less, anise root. Old-growth bur oak forest serving as a reminder of what a virgin forested range was like in a most unlikely grassland region.

148. Shade-adapted range plants- This two-slide set of a north-slope, Nebraska Sandhills bur oak forest featured the 1) herbaceous understorey dominated by long-beak sedge with Canada wildrye as associate species and anise root as principal (essentially sole) forb and 2) base of a mature bur oak with stump sprouts and a sapling. The sapling was at such distance (about a foot and a half) away from the trunk of the adult tree that it was apparently a separate tree derived from an acorn (most likely the adult bur oak it was closest to). Thus this bur oak sapling appeared to be a sexual offspring of the adult oak, a separate and unique genetic individual produced by an adult bur oak through fruit. It was possible that this sapling grew from an acorn produced by a neighboring bur oak and transported next to the big oak shown here by a combination of gravity, wind, and steep slope or by a food-storing squirrel. There was some probability that this sapling was actually a basal sprout, secondary shoot, that arose from the adult tree, but this seemed not to be the case.

By contrast, the small stump sprouts to the right of the sapling were asexual offspring from the large bur oak. In this case the new oak shoots (stump sprouts or stump suckers which are secondary shoots) were clones (clonal progeny) of the parent tree. These were genetically identical to the big bur oak from which they arose. Stump sprouts were secondary shoots of the existing bur oak tree the same as new limbs, branches, and buds. Such clonal shoots are often called offshoots. This asexual reproduction is vegetative reproduction (synonyms), human horticultural forms of include grafting and budding. More (and more clear) examples of suckering from healthy, uninjured, mature bur oak was shown below near end of this section.

Almost all tree species are capable of both sexual and asexual reproduction, but sexual regeneration is less successful in forest of dense shade unless the species are relative in tolerance (Tolerant or Very Tolerant). Vegetative regeneration is not limited (at least not nearly as much so) because the parent tree can translocate photosynthate and other nutrients to its own shoots (clonal organs). By contrast, sexually produced progeny are their "own plants" and must be able to survive under the shade of their parents at age classes ranging from seedling through sapling to pole-size. Most of these individual smaller trees--at least in species having lower tolerance--die. An example of this reality was the stick (at left of trunk and sapling) which was the remains of a small sapling tht could not survive in the shade of (compete with) the aduld bur oak.

Burns and Honkala (1990) reported that bur oak has usually be interpreted as being Intermediate in tolerance rating although certain observers viewed bur oak as more tolerant than other climax oaks such as northern red and white oak. In the Prairie Peninsula Region however bur oak stands have been invaded by other oaks including white oak, and bitternut hickory (Burns and Honkala, 1990). This was far to the east and on more mesic habitats than in the Nebraska Sandhills where the more mesophytic oaks and hickories are absent. These same authors specified that in forests to the east and north bur oak died from suppression (due largely to shading?) after reaching sapling size. That same response was frequent in the north-slope Sandhills bur oak forest described here.

149. Dominants of a deep, dark lower layer- Local sunlit patch of the herbaceous layer in a north-slope bur oak forest in Nebraska Sandhills. Plant species seen here were the climax herbaceous species that dominates the understorey of a sandhills bur oak forest..Long-beak or Sprengel's caric sedge (Carex sprengelii) was the dominant--almost exclusive--species with Canada wildrye the associate species. Anise root was the only forb of consequence in the herbaceous layer. These were reported as characteristic (indicator) herbaceous species in bur-oak dominated range vegetation (Barker and Whitman, 1989, ps.17-18).

The first of these two photographs was of a single-species stand of long-beak sedge. Second photograph included a shoot of Canada wildrye accompanying the long-beak sedge.

150. Contaminated understorey- Sward of herbaceous layer of a north-slope bur oak forest in Nebraska Sandhills consisting of long-beak or Sprengel's sedge and of naturalized Kentucky bluegrass (Poa pratensis). Kentucky bluegrass and smooth bromegrass (Bromus inermis) are two widespread Eurasian, perennial festucoid grasses introduced by the white man that have natrualized widely in North America. These two introduced grasses are commonly used throughout the greater Northern Great Plains Region (as well as areas of adjoining regions) for grazing and, in case of smooth brome, for both pasture and hay. They continue to have ample opportunities for naturalization and establishment across a vast acreage, especially on disturbed sites in humid through semiarid zones, so they are properly regarded as naturalized range plants..

Continued heavy mowing up to edge of the north-slope, old-growth bur oak forest described heein enabled both Kentucky bluegrass (as shown here) and smooth brome (covered below) to invade outer parts of the native herbaceous understorey of this bur oak stand. This invasion allowed displacment, to varying extents, of native graminoid species like long-beak sedge and Canada wildrye. These two agronomic, Eurasian grasses were able to outcompete natives only where there was continued disturbance by repeated, heavy mowing over specific locations or of adjacent areas from which the exotics could spread for short distances into unmowed native sward. The sward shown here was an example of the latter situation.

Cherry County, Nebraska. Late June, peak flowering stage of both long-beak sedge and Kentucky bluegrass.

151. Long-beak or Sprengel's caric sedge (Carex sprengelii)- Three photographs showing progressively greater detail of sexual shoots on the dominant herbaceous species in the understorey of a north-slope Nebraska Sandhills bur oak forest.

Cherry County, Nebraska. Late June, peak flowering stage just after anthesis.

152. Broadleafed Lone Ranger- Anise root (Osmorhiza longistylis) in the herbaceous layer of the understorey of a north-slope bur oak forest in Nebraska Sandhills. This was only forb that this photographer could find in this climax forest range. It is a characteristic species; generally a dominant and indicator species in the bur oak-dominated forests of this region (Barker and Whitman, 1989, p.18). Its graminoid neighbors were long-beak caric sedge, the dominant, and Canada wildrye, the associate species.

Cherry County, Nebraska. Late June, late pre-bloom phenological stage.

153. Invasion at the edge- Lower and outer edge of a north-slope bur oak forest in Nebraska Sandhills with an individual eastern red cedar prominently and happily growing in a mid-layer of vegetation. This immediate local was just above Minnechaduza Creek. This accounted for the lush stand of herbaceous riparian vegetation in the foreground. which "crept in" into this "photo-plot" useed to show size of the cedar relative to typical size of adult bur oak (to immediate right of eastern red cedar). Human suppression of fire had permitted eastern red cedar to establish sporadically both along edge and in interior of the bur oak-dominated forest.

Most of the herbaceous riparian vegetation was the introduced Eurasian grass, smooth brome which invaded the bur oak understorey under frequent, heavy mowing. Also present with much cover and density, though lacking height of the bromegrass,was another Eurasian grass, Kentucky bluegrass. Other riparian species were native grasslike plants (Cyperaceae) that were still only in vegetative stages and unidentifiable by this worker. These had, however, been overwhelmed by the introduced grasses. The only native plants that could persist under cover of the agronomic grasses (which were competitive with native herbaceous species only under heavy mowing) were bur oak, green ash, American elm, and eastern red cedar. And mowing wiped out all plants of these tree species except saplings and adult trees.

154. Bur oak stand at the edge and changed by man- Part of the perimeter of the north-slope Sandhills bur oak forest adjacent to a field of smooth bromegrass. Extension of close (short-height) mowing, over a number of years, into the edge of the bur oak forest had either directly killed out long-beak sedge, Canada wildrye, and anise root and/or permitted invasion of smooth brome and Kentucky bluegrass that "choked out" (outcompeted, overshadded, etc.) these natives.

155. Advance guard of bur oak-dominated vegetation being invaded by enemy legions- Two views of a bur oak forest with herbaceous layer(s) that were highly man-modified. This local small stand of bur oak stood in stark contrast to the virgin climax bur oak forest featured above. These two photographs showed the outer- and lowermost perimeter of the bur oak community covered in this section. The adult bur oaks and a few patches of the natural understorey beneath mature trees had persisted (where oak trunks were too close together to permit entry and operation of rotary mowers [=shreaders]) along this perimenter. Generally, however, continued close mowing of the range vegetation had done two things: 1) prevented regeneration of bur oak by cutting off all bur oak seedlings and 2) largely converted the natural herbaceous understorey to an anthropogenic or manmade (=artificial) layer of smooth brome with local stands of Kentucky bluegrass.

Change in species composition of the herbaceous layer(s), replacement of native species with naturalized Eurasian species, was due to either direct killing of long-beak sedge, Canada wildrye, and anise root by defoliation or indirectly by reducing competitiveness of these range species and/or favoring the taller-growing smooth bromegrass along with denser-growing, more cutting-toleraant Kentucky bluegrass. It was explained above that both of these introduced, agronomic forage grasses have naturalized throughout much of the North America range country. Where mowing disturbance (= abnormal defoliation regimen) occurred throughout much of the growing season the understorey was converted from an herbaceous layer of native grasslike, grass, and forb species to one of naturalized agronomic grasses (ie. conversion from native to naturalized range plants). Also, the lower woody layer(s) was totally eliminated because mowing prevented regeneration of all tree species.

Beyond doubt or debate, continued close mowing as had been practiced on this forest range for years will eventually eliminate the bur oak forest (as soon as the already old trees die off) and convert the plant community into a manmade grassland of smooth brome and Kentucky bluegrass, a farm field of domestic forages.

156. Artificial understorey- Continued close mowing by roatary shredders killed out--directly or indirectly--the climax herbaceous species (long-beak sedge, Canada wildrye, anise root) of a bur oak forest understorey and converted the sward to a single-species layer of smooth brome.A small remnant of smooth bromegrass remained uncut where this beautiful trunk of an old-growth specimen of bur oak prevented mowing (an inexperienced or lazy shredder operator did not get close enough to the oak).

The other glaring outcome of mowing was absence of regeneration of bur oak, dominant tree species, and green ash, the associate species. If present mowing practices continue (and they obviously had been in effect for a number of years) there will eventually be no bur oak forest left. Instead, the plant community will be a monoculture of smooth brome (with local spots of Kentucky bluegrass). All native vegetation will be wiped out (ie. the forest range will be no more and a hay field will have replaced it).

157. Genuine-article understorey- Two trunks of large bur oak prevented close mowing of the native herbaceous understorey comprised of long-beak or Sprengel's caric sedge, the dominant, and Canada wildrye, the associate species. Survival of these climax species permitted some of the composition and structure of a bur oak forest range to persist. This part of the old-growth bur oak forest that had developed on a north slope in the Nebraska Sandhills was mowed with less frequency than some of the other forest understorey with the result that the climax species composition of the sward (herbaceaous layer) persisted. Tree regeneration (bur oak, green ash, American elm) was still completely prevented as any seedling was mowed off where density of adult trees and saplings did not prevent entry of rotary mowers.

158. Nebraska Sandhills bur oak grove- A bur oak grove, the outermost edge of which was shown here, had developed on a sunlit ridge conterminous with the north-slope bur oak forest described immediately above. Both phases--open, fullsun grove and dense, deeply shaded forest--were climax range vegetation and represented the extremes physiographic and structural manisfestations of the bur oak forest cover type. The greatest differences were in the understorey vegetation, as to vegetational structure and species composition of herbaceous and woody (shrub and smalltree) layers.

The bur oak grove phase (or community, if the two extremes were to be viewed as two different range plant communities) had no species of woody plants except bur oak (in contrast to American elm, green ash, and eastern red cedar in the north-slope forest). Also absent from the bur oak grove on the drier and more sunlit ridge was long-beak cric sedge which made up most of the herbaceous biomass on the north-slope forest. Instead, Canada wildrye, associate on the north-slope forest, was the overall dominant of the herbaceous layer in the bur oak grove. Giant ragweed (Ambrosia trifida) was a locally dominant herbaceous species and the most abundant forb in the oak grove. Anise root, the only forb, on the north-slope forest was absent in the grove vegetation.

This bur oak grove was on the border of a field of the Eurasian perennial grass, smooth brome, which, as shown above, had invaded the understorey of a north-slope bur oak forest under repeaded close, mechanical mowing when the native long-beak sedge, Canada wildrye, and anise root were killed out by such extreme (intense and frequent) defoliation. Where trunks of bur oak were too close together to permit intrusion of this bloody equipment and overmowing the native, cool-season Canaada wildrye dominated the understorey other than in microsites where giant ragweed and bur oak stump sprouts held this honor.

Physiogonomy and structure of this Sandhills bur oak grove was presented in this two-slide episode. Details of the herbaceous layer of this grove was presented in the next two-slide episode.

159. Edge of a bur oak grove- Lower zone of tree trunks and herbaceous understorey of a Nebraska Sandhills bur oak grove. This stand of climax vegetation was conterminous with the north-slope bur oak forest featured earlier. In contrast to the deeply shaded understorey of the bur oak forest in which long-beak caric sedge was dominant and Canada wildrye was the associate species, the herbaceous layer of the grove phase of the bur oak cover type was dominated by Canada wildrye except in small areas (microhabitats) where giant ragweed held supremancy or where basal sprouts of bur oak overtopped the dominant cool-season, festucoide grass.

Canada wildrye was featured in both of these photographs with the local sward in left foreground of first slide shown at close range in the second slide. Some of the dead (light brown or buckskin-colored) shoots of Canada wildrye included some of the previous year's growth (slightly more faded) as well as some of those of the current growing season. Almost all of the current year's shoots of Canada wildrye were still in the boot. It was not known why a few of the current growing season's shoots had already matured, died and gone into dormancy. Did make for a nice contrasting picture with Canada wildrye very conspicuous.

Giant ragweed, a warm-season annual composite of mature size that lives up to its common name, was still in early growth and thus not shown in proportion to its yield of biomass at peak standing crop. This herbaceous understorey was the vernal society even though it was summer and bur oak were representative of the estival aspect.

160. Parents, progeny, and playmates- Sprouting (suckering), the production of secondary shoots, from base of trunks in non-injured adult bur oak trees. Bur oak in both of these "photo-plots" were on a ridge at edge of a bur oak grove where light could penetrate from all directions throughout most of the day. This was a different condition of radiation than that of the north-slope bur oak forest described at beginning of this section. Differences in understories of the bur oak grove considered here and the bur oak forest described previously were explained in the immediately preceding caption.

It was strikingly evident that full-grown (adult) bur oak produced basal sprouts in both deep shade and full sunlight (forest and grove stands, respectively). This was an understandable characteristic when it was born in mind that these secondary shoots were being supported by the parent shoot (ie. sprouts were a photosynthate sink from the parent tree that was the a nutrient (food) source for the basal suckers. (Sprouting frrom stumps and basal trunks of bur oak was considered in more detail in the next succeeding set of photographs.)

What was substantially different in understories of bur oak forest versus grove was in herbaceous species and tree species other than bur oak (see again preceding caption). Mature sexual shoots of Canada wildrye, the overall dominant herbaceous species in the bur oak grove, with conspicuous spikes were present in the first of these two p;hotographs. Also prominent in this first slide was the pioneering, annual composite, giant ragweed. The second slide presented a fullsun shot of a basal sprout of bur oak at edge of the grove where frequent mowing had killed out the native Canada wildrye and its replacement with the introduced Eurasian Kentucky bluegrass.

161. Living stumps- Two stumps of bur oak with prolific and vigorous sprouting or suckering. These trees were at edge of a bur oak-dominated forest in the Nebraska Sandhills. Stump sprouting is an adaptation to fire, a key abiotic factor of grasslands. Bur oak is one of the most fire-adapted Quercus species in North America with sprouting from stumps or injured tree trunks one of its most important means of regeneration. In fact, bur oak sprouts prolifically even from old trees and those not subjected to injury. This was shown in several preceding photographs for bur oak growing in deep shade and fullsun environments.

Bur oak has long been recognized for its "thick fire-resistant bark" (Burns and Honkala, 1990), but prolific sprouting (suckering) is an accompanying adaptation to recurrent fire that was evolved in the generally fire-prone habitat of this species biological range. Burns and Honkala (1990) explained that prolific sprouting was common following burning or cutting of bur oak only up to pole-size with such secondary shoots being of poor quality except those of seedlings. This latter conclusion was confusing to say the least given that shoots of seedlings are not sprouts (secondary shoots) at all but rather primary shoots derived from acorns. These same authors noted that larger trees (mature or full-grown age class?) also produced basal sprouts but that vigor and quality of these sprouts had not been evaluated relative to age, size, etc. of parent trees.

The two examples shown here were pictorial evidence that seemed to contradict findings reported in Burns and Honkala (1990). The profuse (and plenty vigorous) stump sprouts shown off here were from mid-size trees (a foot or more in basal diameter). This was considerably smaller than the full-grown bur oaks presented in the immediately preceding set of two photographs, and these appeared vigorous enough too.

Cherry County, Nebraska. Late June.

162. Fire ran through the bur oaks- At the outer edge of a grove form of a bur oak forest along a small stream through a hot fire with high flames had burnt just two to three prior to time of photograph. This forest range was in the Dissected Till Plains of the Central Lowlands physiographic province of northeast Kansas which is about the southern limit of forest dominated by bur oak. Thee two slides presented an outside-the-forest view to show physiogonomy and structure of the plant community.

The lush growth of the herbaceous layer was dominated by seedlings of giant ragweed (Ambrosia trifida) with scattered plants of Canada wildrye, Canada wood nettle (Laportea canadensis), and pokeberry or pokeweed (Phytolacca americana). Giant ragweed is a pioneering annual; in fact, it is the most abundant pioneer or colonizing forb in this area. The hot fire had been a disturbance of such severity as to create an ideal habitat for invasion by giant ragweed which "eclipsed" the other herbaceous species which were perennials. These perennials had been present years before the burn, but they, too, appeared to have benefitted from the fire jucging by growth of other plants of these species in a few isolated spots that did not burn. This phenomenon was explained in captions below.

The saplings in foreground of these (and subsequent) photographs were all hackberry and American elm. Almost every one of these saplings (and seedlings that were too small to show up in the slides) were top-killed by the heat of the obviously hot fire which burned with intensity adequate to partially kill lower branches of bur oak. This latter feature of the fire was shown and described in greater detail below. In this region most climax bottomland forests are dominated by various combinations of hackberry, American elm, slippery elm, and green ash (the Tolerant climax species) with old trees of such Intolerant, colonizing species as eastern cottonwood, sycamore, black walnut, and honey locust persisting into climax as associates. This is Society of American Foresters (Eyre, 1980) cover types 93 and 94. These mixed hardwood forests are the climatic climax. By contrast, bur oak forests, Society of American Foresters (Eyre, 1980) cover type 42, are a pyric climax. Differences in alluvial soils of these floodplain forest are not so different as to account for differences in forest range types.

In the absence of periodic fire the bur oak forest would eventually proceed through plant succession to a hackberry-American elm climatic climax. That is, it would be the potential natural vegetation along streams in this climatic regime as interpreted from perspective of polyclimax and climax pattern theories. Or, what amounts to the same thing, bottomland forests dominated by hackberry and American elm would be the edaphic climax, the natural termination of such stream bottom seres. Either way, it is only periodic hot fires that maintain bur oak, which is Intermediate in tolerance (Burns and Honkala, 1990), as climax along stream bottoms (ie. bur oak is a fire type, a pyric climax). In monoclimax theory all such forests are postclimax to the climatic (= zonal or regional) climax of tallgrass prairie.

Individuals of bur oak would undoubted persist into a hackberry-American elm climax as bur oaks are relatively long-lived. Burns and Honkala, (1990) reported that some bur oaks bear fruit up to ages of 400 years, the longest of any Quercus species in North America.

Progression through plant succession from a seral bur oak-dominated forest to a hackberry or hackberry-elm climax forest was the pattern of vegetation development predicted for gallery or floodplain forests in northeast Kansas by Bellah and Hulbert (1974) and Abrams (1986). Abrams (1985) concluded that fire frequency (mean fire interval) bur oak-chinquapin oak gallery forests in the Flint Hills ranged from about eleven to twenty years with an average "somewhere between that range" but with a historic interval of two to three years. Clearly the historic frequency of two to three years would have maintained the oak forests and prevented progression to hackberry or hackberry-elm. It is likely that even an average fire return interval of roughly fifteen years in contemporary time would maintain the bur oak-chinquapin oak forest. Again, bur oak forest (SAF 42) is a fire type or pyric climax.

Spring Creek, Marshall County, Kansas. Mid- June, vernal aspect. FRES No. 15 (Oak-Hickory Forest and Woodland Ecosystem). No Kuchler unit for bur oak forest; closest was Bur Oak Savanna (unit 81 in Kuchler, 1964, unit 72 in .Garrison et al., 1977, including map). SAF 42 (Bur Oak). In Brown et al. (1998, p. 37) would be Quercus macrocarpa Association 122.11? (say 111) of Oak-Hickory Series 122.11 of Northeastern Deciduous Forest 122.1. Western Corn Belt Plains, Loess and Glacial Drift Plains Ecoregion 47i (Chapman et al., 2001).

163. Late spring after fire-Apperaance of a bur oak grove two to three months following a hot fire that effectively top-killed seedlings and saplings of hackberry and American elm that had established beneath the bur oak canopy. Fire intensity was adequate to create a disturbance that favored rapid establishment of a dense population of giant ragweed, the most common and prolific pioneering plant in this region of the Dissected Till Plains of northeast Kansas. Rapidly growing seedlings of giant ragweed, an annual composite, accounted for the greatest herbaceous cover, but there was also an abundance of Canada wildrye and pokeweed (though widely scattered with most cover being local) along with local exclusive colonies of Canada wood nettle (see photograph and caption below). At outer margin (just under forest canopy) there were large individuals of what appeared to be--without much familarity of early growth shoots--giant sumpweed (Iva xanthifolia).

The first of these two photographs was a closer-in view of the bur oak at center-left in the second photograph of the preceding two-slide set. The trunk of this tree had split almost to ground level yet was still standing and healthy. Heartwood of a tree is dead tissue anyway so as long as the tree was not weakened to point of crashing and did not have heart-rot it remained as healthy is if the trunk was intact. The second of the photographs of this caption presented a summary view showing several top-killed saplings of hackberry and American elm. The rightmost bur oak (center-right) sported an old fire scar and ws in every way healthy from all outward appearances. This fire-scarred tree was featured below.

164. Old and the new after a fire- Close-growing and very old bur oaks (first slide) along with seedlings of giant ragweed and this season's shoots of Canada wood neetle, pokeweed, and Canada wildrye as an herbaceous layer plus some saplings of hackberry and American elm (see especially second slide) comprised the range vegetation of a bur oak forest two to three months following a hot surface fire. In the background there were several pole-sized trees and saplings of red mulberry (Morus rubra) that formed an erratic lower tree layer. One of these saplings was shown in center midground of the second slide. The sapling in center foreground of this second photograph was one of the few young hackberries that was not top-killed by the fire. Other saplings of hackberry and American elm that were not topkilled outright had already started to "peel bark" and appearedlikely to die. The hackberry sapling featured here defied the odds and appeared ready--at this juncture anyway--to take its place ultimately as an adult in the grove of bur oak.

It was explained in the immediately preceding caption that bur oak is a fire type forest. In absence of periodic fire bur oak--other than as a few persistent old-age trees--would be replaced by hackberry and American elm which would be the climax dominants on this bottomland sere. The latter two are Tolerant species whereas bur oak is Intermediate in tolerance rank (Burns and Honkala, 1990). Of course, fire is as much as a part of climate (or a consequence of climate if one prefers) as drought, wind storms, and floods. More precisely, lightening is as much part of the atmosphee as precipitation and temperature and fires from lightening with fuel made possible by climate are major factors responsible for maintenance of bur oak forests within the surrounding zonal vegetation of tallgrass parairie.

Various studies such as those by Kucera (1960) and Bragg and Hulbert (1976) showed that woody plant communities, including forests, expanded in the tallgrass prairie region since European settlement (due in large part to fire suppression). Abrams (1985) estimated that the mean fire interval for bur oak-chinquapin dominated gallery forest in the Flint Hills of Kansas was two to three years and roughly eleven to twenty years with intervention by white settlers and contemporary man. Abrams (1986) documented this phenomenon and predicted that hackberry, elm, and redbud (Cercis canadensis) would gradually replace bur oak and chinquapin oak--at least in absence or reduced frequency of fire--as the climax forests for bottomland forest sites in the Flint Hills and Dissected Till Plains in northeast Kansas. Abrams (1992) issued a later report based on his earlier findings and concluded that for some areas of Kansas the presettlement vegetation of tallgrass prairie had become either a bur oak-hackberry overstorey with a hackberry-elm understorey or a chinquapin oak overstorey with a elm-redbud-chinquapin oak understorey. This analysis struck the current author as an interim report because it seemed likely to him that the ultimate state would be a climax hackberry-elm forest.

165. Just another encounter with fire- Outer edge of a bur oak grove two to three months following a surface fire that burnt through this bottomland forest. Judging from fire scars and general understanding of bur oak forest and the natural envioroment of this area it was obvious that this was the most recent of many such fires in these old bur oaks. The fire had been hot enough to create a disturbance so severe that giant ragweed, the most abundant pioneer species in this area, had already established populations that pretty much excluded other herbaceous species except the climax perennials, Canada wildrye and Canada woodnettle (wood nettle). Even these shade-tolerant and already present perennial herbs appeared to have benefitted greatly form the fire. Without this fire a dense layer of bur oak leaves would functioned as mulch and largely smothered most herbaceous plants. Such a layer of large bur oak leaves (= mulch) was present in several small spots that did not burn. Giant ragweed was absent from these and Canada wildrye plants were smaller than those growing on land that had burned.

Note that the lowermost branches of bur oak were largely leafless, but with enough leaves to prove that they were still alive (barely) and that heat from the last flames injured (appeared to have more-or-less killed) these smaller, lower limbs. This was an example of fire-pruning, but such defoliation did not necessarily kill these organs. It was likely that new shoots would arise from intercalary meristem on these lower branches.

The sapling to right of foremost bur oak was hackberry. It leafed-out following the blaze, but was nonetheless severely injured by the heat from had to be an unusually hot fire. This one of the few hackberry saplings that was not totally top-killed and it had entire strips the total height of the shoot that already had peeling bark. All American elm sapling in the understorey were top-killed. Abrams (1985) studied fire frequency within gallery forests of northeast Kansas (the Fllint Hills) and found a natural fire frequency of two to three years and an extended mean fire interval of roughly fifteen years during time of occupation by European man. Either the natural or anthropogenic fire frequency would probably maintain bur oak groves and prevent development of hackberry-American elm forest on the forest range site featured here.

The fire scar on the foremost bur oak was an old wound that was already present and in process of healing before the recent blaze. This "honor scar" was presented and described further in the next slide.

166. New beauty in an scar- An old fire scar on an ancient bur oak that was renewed by a surface fire only two to three months prior to time of photograph. The tree had started started healing the wound caused from previous fire(s) and the most recent burn did not harm the new bark tht was slosly growing over the scar. This was a direct view of the scar that was shown from the side in the foremost bur oak featured in the immediately preceding two slides. Forbs growing in front of the oak were young seedlings of giant ragweed, the herbaceous species that most benefitted from the recent fire.

This is the "price" ("rent" so to speak) to be paid by the fire-adapted bur oak for living in a pyric habitat in which less fire-adapted and more tolerant hardwoods such as hackberry and elms cannot survive. In absence of periodic fire hackberry, green ash, American elm, and perhaps boxelder would eventually replace bur oak through plant succession. These more tolerant species are the climatic climax whereas bur oak is a pyric climax (ie. bur oak forest is, in effect, a fire type in the overall environment of the Dissected Till Plains or, sometimes, Glacial Drift Plains of northeastern Kansas).

Spring Creek, Marshall County, Kansas. Mid- June.

167. After the latest in a long history- Inside a bur oak grove through which a hot surface fire burned two or three months before. This bottomland forest range had developed along a small stream at edge of a tallgrass prairie in the Dissected Drift Plains of northeastern Kansas. There were several "featured attractions" in these two photogrphs. The most prominent of these was the large fire scar on one bur oak trunk that extended from the ground to over 15 feet in height. this was an old scar from previous fire(s) that was "freshened up" by the most recent burn.

Another, though much smaller, fire scar on another bur oak tunk was presented and discussed in the immediately preceding photograph and caption. The current author interpreted bur oak forests in the Dissected Till Plains as a fire-climax type with bottomland forests on this forest site in absence of recurrent fire developing through plant succession to a climax hackberry-American elm forest.

Effects from fire wounds and scars on bur oak are probably not know with any certainity. Entry of disease pathogens (eg. various forms of fungal rot) and insects through tree wounds, including those caused by fire, is always a possibility. One common suspicion--though perhaps without scientific proof--is that fire (heat or charring of wood) has something of a cauterizing effect so that disease entry is less likely with fire wounds/scars than with similar wounds (eg. those ranging from ax blazes to debarking by falling trees). The charred (charcoal) surface of a fire wound, even a fresh one) is a different (drier, perhaps chemically) environment than the moist, peeled-surface wound left by mechanical injury.

What is certain from even brief scanning of the literature is that bur oak fire scars as records of fire regimes, especially fire frequency, have been analyzed in considerably more detail than the impacts of fire damage on tree health. It is also certain that fire in bur oak-dominated and influenced communities (forests, open groves, savannahs, even prairies) is a natural part of the habitat of this range vegetation. Furthermore, it follows that bur oak is adapted to fire and, was the species not so adapted to and tolerant of fire to the degree it is, this species would not be a member of these range plant communities. It is axiomatic that the overall impact of fire on bur oak is minimally adversive, neutral at least, and almost assuredly positive for survival in range vegetation of which it is an important member.

Peterson and Reich (2001) concluded that on bur oak was a fire-resister, a designation given by Rowe (1983) to shade-intolerant tree species that suffer little or no damage from low-severity fres. Peterson and Reich (2001) explained that "[f]ire rarely killed mature bur oaks, even those in the smaller size classes ...". They (Peterson and Reich, 2001) noted further that even saplings of bur oak grew corky bark of such thickness as to protect the cambium from most fires. Burns and Honkala (1990) cited a volume of literature attesting to the thick fire-resistant bark of bur oak, which along with its general drought-tolerance, accounted for presnece of bur oak on xeric sites as well as mesic ones where bur oak was an associate on sugar maple-American beech forests.

Another "featured attraction" in this pair of photographs, especially the second one, was the death (or near death) of shoots of hackberry and American elm saplings standing in stark contrast to the survival of adult trees of bur oak even with fire scars where sizable portions of their trunks were removed. This is a photographic lesson showing that it is primarily periodic fire (with browsing obviously less important) that maintains bur oak groves and forests which would otherwise develop into hackberry-elm forest with only persistent and senescing adult bur oaks (at status of associate species at most). Bur oak forests and woodland as pyric climax (a climax fire type) was discussed in above photo captions (complete with citation of relevant literature) so that further discussion was not deemed necessary or desirable in this current caption. This was an opportune point to acknowledge that in more xeric environments (eg. those to the west the Dissected Till Plains such as the Smoky Hills or Sandhills in subhumid to semiarid precipitation zones) it is probable that limited soil moisture, especially in drought, rather than fire is the primary variable responsible for maintenance of bur oak and restriction of Tolerant tree species like hackberry, elm, box elder, etc.

Also featured here was presence of red mulberry (lower branch with large leaves extending downward from upper-left corner of first photograph). Red mulbery was usually observed to be a smaller tree of the second woody (lower tree) layer, but as one of the--if not the single most--consistent tree species in bottomland forests in humid and subhumid zones extending from the Cross Timbers and Central Prairies in Texas, Ozark Mountains in Missouri and Oklahoma, and through to the Great Plains in Nebraska. In southern mixed hardwood forests, such as those in northcentral Texas, red mulberry frequently grew to relatively large size (eg. 16-18 inch DBH) with straight boles. Red mulberry was found as a consistent member of bottomland forests were dominance varied from that by eastern cottonwood, sycamore, pecan, bur oak, elm, green ash, and hackberry or sugarberry and where soil texture ranged from primarily sandy to predominantly clay. In progressing northward, dominance by members of Ulmaceae goes from exclusively sugarberry (Celtis laevigata) as in north Texas to side-by-side co-dominance of sugarberry and hackberry (C. occidentalis) in northern Oklahoma to exclusively hackberry in northern Kansas and Nebraska. Red mulberry grew with an array of dominant tree species. Again this was usually, though not always, as an understorey or lower-height tree species.

Species in the herbaceous layer shown in these two photographs included giant ragweed, Canad wood nettle, Canada wildrye, pokeweed, and giant sumpweed in that order based on estimated relative cover. Giant ragweed, an annual composite, was the number one pioneer species of denuded land in this area and far-and-away the dominant of the herbaceous layer except where there were local colonies of Canada woodnettle farther in the interior of this bur oak forest. Canada wildrye, a festucoid grass of the barley or wheat tribe (Hordeae or Tritaceae) that responds to disturbance as a decreasere, was able to "hold its own" against the rapid-growing and rank seedlings of giant ragweed. Giant sumpweed was present as sparse though very conspicuous individuals.

168. Sting after the burn- Local colony of Canada wood nettle or, sometimes, stinging nettle (Laportea canadensis) in the interior of a bur oak forest in late spring after a fire in late winter or early spring only a few months earlier. This species is widely distributed in moist forest with a species range in North America from Saskachian east to the Maritime Provinces and south to Florida and west to eastern third of Kansas. This member of the spurge family (Euphorbiaceae) packs quite a sting, condiderably more so according to Stephens (1980, p. 21) than the stinging nettles (Urtica species). Wear long pants and move through it gingerly. The author has negotiated many of a patch of Canada wood nettle and never gotten more than a tiny tingle by showing it the respect it deserves.

The wood nettle was accompanied by several plants of giant ragweed.

Marshall County, Kansas. Mid-June.

Bur Oak (Quercus macrocarpa)-Basswood (Tilia americana) Forest

This section is more-or-less a variant of the bur oak cover SAF 42 (Eyre, 1980), but often with American linden or basswood (Tilia americana) as a co-dominant to dominant to strong associate tree species often varying locally (more like spot-by-spot). This bur oak to bur oak-basswood forest was on Stone State Park in Plymouth and Woodbury Counties, Iowa near the northern terminus of the Loess Hills and adjacent to the Big Sioux River with an elevation of roughly 12000 feet. The successional status of this forest and the forest-tallgrass prairie edge is uncertain. While the history of human occupation (meaning the recorded and/or documented coccupationa by Europeans) is complete, botanical/vegetational inverntories or, even, descriptions are incompplete. It is for certain that the trees (all native) increased in abundance and cover in what under reported "virgin" condtion (early white man entry and occupation) was tallgrass prairie, some nearby examples of which have been preserved..

Not withstanding its "clouded" more recent (whiteman era) ecological past, it seemed plausable that this was a pocket of natural hardwood forest pocket in an otherwise tallgrass prairie area of the famed Loess Hills Region. Bby the standards of this regional topography the land shape of Stone State Park is one of high hills and "hollers" with loess bluffs to deep draws or ravines.It is likely that the native tree species would be more likely to secure a "roothold" in this comparatively small area (slightly more than 1,000 acres) than more exposed areas of the Loess Hills.

Role of Indian (Yankton Sioux, at time of European penetration) burning, which almost assuredly took place regularly, and hunting, especially of buffalo (Bison bison), can never be known, but enough is known generally to acknowledge that Indian management would have favored grassland at expense of forest or woodland. It is also safe to assume that the Sioux would have preserved bur oaks for their annual crops of large acorns (the largest of any Quercus species in North America). Typical invasion of the native (natural) vegetation--whatever it was--by Eurasian plants introduced by the whiteman and, which promptly became weeds was obvious in Stone Staate Park. Some of these Eurasian weeds were included in this photographic documentation of currwent forest range vegetation. The role of man in manipulating and changing the "virgin" vegetation cannot be denied.

Enjoy the 'woods" either way and recognize it as a variant of bur oak forest.

As rich as it gits- Roadcut through the famed Loess Hills of central North America one of the deepest deposits of rich soil on Earth. There are also various geologic strata that inlude sedimentary layers including shale, sandstone, limestone and lignite. This soil was the basis of a bur oak-basswood forest in this Loess Hills Region.

Loess is simply wind-deposited soil, much of which is typically predominately silt although the other two soill seperates, sand and clay, may also be present. Loess deposits in the Missouri River Valley and adjoining local areas took place during the Wiscondin Glacial Period of the Pleistocene geological epoch roughly 12,000 to 31,000 years Before Present. Loess deposits in the Missouri River Loess Hills are deep by soil standards being anywhere from 60 to even 200 feet in depth (Iowa Geologic Survey, Loess Hills, online). Actually, loess in the Western (Missouri River) Loess Hills is the result of three separate depositions beginning with the Loveland, then the Pisgah, and most recently the Peoria at roughly 120,000 to 15,000, 25,000 to 31,000, and 12,500 to 25,000 years Before Present, respectively (Iowa Geologic Survey, Loess Hills, online).

Landscapes of loess deposits (these occur in various regions on Earth, including several in North America such as in the Palouse Prairie area on the inner Pacific Northwest. Loess deposits typically have divided--often intricate and deep--drainages resulting in ravines, coulees, hollows, etc. while the tops of low hills have prominent crests, ridges, and "hogbacks".The Western Loess Hills of Stone State Park,, Pllymouth County, Iowa (northwestern Iowa along the Missouri River) provided an outstanding textbook example of a loess-deposit landscape.The range vegettion of these hills was a bur oak-basswood forest and tallgrass prairie- hardwood forest ecotone. A "virgin" tallgrass prairie, the Broken Kettle Grassland Preserve, that developed in the Western Loess Hills (also in Plymouth County, Iowa) was treated in the chapter, Tallgrass Prairie of Range Types of North America.

A good consise, yet thorough, summary of the Iowa Loess Hills was provided by the Iowa Geological Survey (online) based on Landforms of Iowa, by Prior (1991).

Stone State Park, Plymouth County, Iowa. Mid- June, vernal aspect. FRES No. 15 (Oak-Hickory Forest and Woodland Ecosystem). No Kuchler unit for bur oak forest; closest was Bur Oak Savanna (unit 81 in Kuchler, 1964, unit 72 in .Garrison et al., 1977, including map). SAF 42 (Bur Oak). In Brown et al. (1998, p. 37) would be Quercus macrocarpa Association 122.11? (say 111) of Oak-Hickory Series 122.11 of Northeastern Deciduous Forest 122.1. Western Loess Hills Ecoregion 47m (Chapman et al., 2002; Omernik et al. Undated).

Wooded edge- Exterior of a bur oak-basswood forest in the Loess Hills of northwest Iowa. The first slide showed the crown of eastern hophornbeam (Ostrya virginiana) at this outermost edge. The second and third slide were a pair of "nested photoplots" with the second slide being a closer-in view (the "nested" part) of a basswood (largest tree trunk at left) and two smaller eastern hop hornbeam to right of basswood. The understorey consisted of dwarf white wake-robin or snow trillium (Trillum nivale), the broadleaf in foreground of third slide; Canada wildrye (Elymus canadensis);, Pensylvania caric-sedge (Carex pensylvanica); and candle wind flower or thimbleflower (Anemone cylindrica).

Heartland wooded slopes- Steep slopes near the hill crest of loess depoosits (Western Loess Hills of Missouri River Valley) with American linden or basswood, the larger trunks in both of these slides including tree in midground of the first slide that had three suckers or secondary shoots coming off of the main trunk, and eastern hop hornbean, the smaller trunks in both of these photographs. Limited understorey of Canada wildrye, Pensylvania caric-sedge, snow wake-robin or swarf white trillium, and thimbleflower.

Asexual reproduction by development of secondary shoots arising from the lower trunk is a unique morphological adaptation that is a major feature enebling basswood to be one of the most Tolerant (to shade, competition, soil space) of all tree species in the eastern deciduous forest of eastern North America. (Further examples of secondary shoots developing off of the main trunk of basswood were presented below.)

Small hole in dense woods on a steep slope- In a bur oak-basswood forest in the Loess Hills Region or northwest Iowa a small tree of eastern hop hornbean (and one directly behind) with one of the better developed patcches of understorey in a bur oak-basswood forest. Understorey species included snow wake-robin or dwarf wh;ite trillium, Pensylvania caric-sedge, Canada wildrye, candle windflower, and white snakeroot (Eupatorium rugosum), the infamous poisonous range plant responsible for the "milk sick" that was responsible for deaths of many pioneers in the earliest days of white settlement.

Other tree trunks in bckground and to side wre mostly eastern hop hornbeam, one of the most Tolerant hardwood species in North America. Eastern hop hornbem is one of the major understorey shrub in the deciduous forest of eastern and central North America.

Internal covering of loess slopes- Inside of a forest of baswood and bur oak (co-dominants in this part of the forest) that developed on the Western Loess Hills of northwest Iowa. Very poorly developed understorey (often consisting mainly of stuuntd plants of Canada wildrye and Pensylvania cari-sedge. A forest floor strewn with dead tree trunks, limbs, branches , etc. is typical ofa climax or, at least, late succcessional stage . Many trees of the two dominant trees and of the dominant shrub, eastern hop hornbeam, were senescing and there was limited regeneration--though aparently adequate reproduction for sustained dominance--by these woody species.

These two views were near the crest of fairly steep hills formed by Pleistocene epoch, the Ice Ages, the latest of which being the Wisconsin Glaciation (Ice Age) when this loess was deposited. The two largest trunks in center midgrorund of the first slide and left midground of the second slide were bur oaks. Trees to left of the two bur oaks in the first sldie were basswood. Trees (trunks) in foreground of both slides were eastern hop hornbeam.

Local dominants- Two views of American linden or basswood, the local dominant tree, and eastern hop hornbeam, the dominant shrub, at or near the crest or ridge of loess deposits in a bur oak-basswood forest in the Missouri River Loess Hills in northwest Iowa. Here, basswood was the clear dominant and comprised all of the larger tree trunks in these two photographs (eg. largest trunk at left in second side). The foremost trunk at right foreground of second slide was eastern hop hornbean.

There was very limited sexual reproduction of either of these species, but existing ones were all young adults as, for instance, pole-size basswood.

Dead, half-rotted wood (of basswood and eastern hop hornnbeam) on the land surface was typical of an old-growth forest, but this particular hill crest portion of this bur oak-baswood had been disturbed by some atmospheric phenomenon--perhaps ice or wind storm--that had broken off branches, major limbs, and even entire mature treess. (Snapped off tree trunks and fallen mature trees at this exact location were presented and discussed below.) The canopy of this forest was so neary closed thaat there was very little understorey. Canada wildrye, pensylvanica caric-sedge, white snakeroot, thimbleflower, and snown trillium were the major herbceous species.

Trunks of dominants- Two boles of American linden or basswood at left and a large straight trunk of eastern hop hornbeam at right represented the local dominant tree andshrub, resectively,in a mixed hardwood forest, mostly of bur oak and basswood, that developed on the deep rich soil of the Missouri river Valley Loess Hills in northwest Iowa. Basswood is classified on the tolerance (to shade and competition) scale as Tolerant (being second only to sugar maple which was no tpresent in this forest). Eastern hop hornbeam is perhpas the most Tolerant of the Tolerant species in eastern North America.

The two shoots of basswood (and other earlier photographs of multi-shooted basswood) showed to viewing students the rather unique morphological/regenerative feature (adaptation) of sprouting on sending up 'side shoots" or development of secondary trunk shoots in the Tolerant Tilia americana.

Two downed dominants- Downed trunk of an adult American linden or basswood on a steep slope of loess, the soil of the Missour River Valley Loess Hills on northwest Iowa on which this giant lived, died, and fell. It could not be determined if this tree, which was rotten at its base (had rotted off perhaps), had died before it fell or its fall (perhaps due to wind or pull of gravity in wetloose soil) was its cause death and the base being closer to the soil had rotted off after falling. Also present was the smaller bole of an eastern hop hornbeam lying atop the basswood log.It was not determined if the crash of the basswood (living at the time or a snag?) had brought down the eastern hop hornbeam or if this small tree or large shrub fell of its own accord. At any rate big tree and big sh;rub (or little tree) were down and this had created a forest gap that was ready for invading plants.

The immediately following two sets of slides and captions featured two bur oaks that had clearly been snapped off as if by wind,r ice, or heay snow. So it was likely that this large basswood had also fallen victim ot the whims of Mother Nature.

Most of the plants in the understory of this forest opening were at an unidentifiable (at least to this photographer) at their very immature phenological stages, but seedlings of basswood and eastern hop hornbeam were present. Other forbs were individuals of those mentioned above: Canada or nodding wildrye,Pensylvania caric-sedge, white snakeroot, snow trillium, and thimble wind flower.

Anoter (second) downed big 'un (but ya can't keep a good tree down)- A set of "nested photoplots" featuring a snapped off bur oak in the Western Loess Hills of northwest Iowa that had resprouted from the remaining stump. The broken off trunk in left midground of the first slide was shown at closer distance in the second slide with coppice shoots, stump sprouts, epicormic shoots, whatever arising from base of the broken off snag. Cause of this breakage of an adult bur oak still in "prime of life" was not know other than the obvious fact that something such as wind, heavy ice or snow had broken it off rather than uproot it. This bur oak was still young enough that it could sprout from heretofore suppressed basal meristem or epicormic buds. In other words the same genotype was ready for a "second cutting".

The clump of three trunks in right foreground was one tree (one genotype) of basswood or American linden as, most likely, was the smaller clump with even more boles at left rear. While bur oak is rated as I:ntermediate in tllerance (for shade, spce, competition in general) basswdd has traditionally been rated asTolerant. Basswood is amon the most tolerant hardwood tree species in the eastern deciduous forest "just below" sugar maple, which did not occur in this rich, deep loess habitat.

This rangeman suspected that bur oak and baswood were co-dominants on the upper loess (hill crests in contrast to ravines or hollows) forest. Successional status of this forest was not known, but fit reasonably well with the Society of American Foresters (Eyre, 1980) forest cover type No.42 (bur oak), or at least a variant thereof. Perhaps basswood is the ultimate climax or een postclimax in the Clementsian (1916) scheme. Clearly weather conditions (eg. climate) was a factor in this woods.

The understorey had some seedlings--though sparse in density--of bur oak, baswood, and esstern hop hornbeam plus a "thin covering" of herbaceous species including white snakeroot, thimble wind flowr, Pensylvanica caric-sedge, nodding or Canada wildrye, and snow trillum or snow wake-robin of those that could be identified at this phenologic estage of development.

And still yet another, a third, downed adult- A bur oak that was "still in its prime" (mature adult-size and not yet senescing) had been broken right at ground level by something, some meterological "agent" such as wind, ice or heavy snow. The long basal part of this downed snag was part of an upper horizontal root. In the first slide the big standing tree in right foreground was an adult bur oak as was the two-trunked (forked trunk) adult tree in right rear background. The smaller (shrub-size) tree between these two trees and partly behind the foremost bur oak was a young basswood with its common habit of having several baal shoots (trunks).

Trees in the background of the second (lower) slide were of the three dominant woody species, eastern hop hornbeam being the third.

At this location, there were a "good number" of seedlings of both bur oak (mostly) and basswood. A nice seedling of bur oak was presented in the center foreground of the second slide) while several were visible to immediate left of the large bur oak in right foreground of the first slide. . Also in the understorey in these "photoplots" were herbaceous species including (among those that could be identified at this stage of their growth) white snakeroot, thimble wind flower, dwarf white wake-robin or snow trillium, nodding or Canada wildrye, and Pensylvanica gne not t

Mid-slope of a loess hill About midway up a reasonable steep hill in the Western Loess Hills in northwest of Iowa. A large "sawlog-size" anf fully healthy bur oak with a multi-layer understorey including 1) a high shrub layer dominated by eastern hop hornbeam, 2) a mid-woody layer dominated by buckbrush or coral berry (Symphorcarpus obiculatus), 3) a lower woody layer of seedlings of bur oak and basswood, and 4) an herbaceous layer which was featured in the next three slide-caption sets.

Woody plants in the background were mostly eastern hop hornbeam and baswood.

On the base- By the basal trunk of a large adult bur oak the herbaceous layer of the understorey of this bur oak-basswood loess hills forest was dominated by Pensylvanica caric-sedge (Carex pensylvaniicus), snow trillium or snow wake-robin (Trillium nivale), and white snakeroot. Some forbs coould not be identified at the early growth stages that existed at time of the slide.

At bottom- Two "photoplots" of the herbaceous layer of the understorey of a bur oak-basswood loess hill forest in the Missouri River Valley Loess Hills in northwest Iowa.. In the first of these two slides the predominant plant was tentatively identified as woodreed grass (Cinna arundinacea) with Pensylvania caric-sedge as a grasslike plant and the composite forb being white snakeroot (Eupatorium rugosum). In the second slide there were seedlings of bur oak and eastern hop hornbeam along with young plants of white snakeroot, thimble wind flower (Anemone cylindrica), purple meadow-rue (Thalictrum dasycarpum).and numerous plants that could not be identified at their young stages of growth. The limb in the first slide was basswood while most of the downed branches and limbs in the second slide were bur oaak. Many of these downed branches appeared to be from some disturbance like wind or an ice or snow storm.

Plants from different backgrounds- Two more "photoplots" ofthe herbaceous layer of the understorey of a Western Loess Hills bur oak-basswood forest in which eastern hop hornbean was the dominantshrub or small tree species. Prominent vascular plants in these two slides were white snakeroot, Pensylvanica caric-sedge, and, in the second slide, a seedling of eastern hop hornbeam (Ostrya virginiana) . The comspicuous plant in both slidess was the toadstool or mushroom, peppery milkcap (Lactarus piperatus).

Almost all contemporary botanists place the fungi in the kingdom. Fungae. Most fungi, including peppery milkcap mushroom, are decomposers that feed on the nutrients from rotting organic matter like the hardwood leaves seen here. The leaf layer of this hardwood forest was the O horizon of this rich loess soil. Again, this leaf layer was composed mostly of leaves of the dominant trees, bur oak and basswood, and, secondly, of the dominant shrub, eastern hop hornbeam.

The small log and the snag it fell from were eastern hop hornbeam.

Sorta milky- Peppery milk-cap mushroom (Lactarius piperatus) growing of the floor of an American basswood-burr oak forest in the Loess Hills of northwest Iowa.

Stone State Park, Plymouth County, Iowa. Mid-June.

Down a "holler"- In a ravne or draw of a bur oak-basswood forest in the Western Loess Hills that formed above the Missouri River in northwest Iowa. The (upper) of these two slides presented two bur oaks and along the right margin two bassood trunks (whether this was one tree or two separates genotypes wasnot known). Thhere were some sapoings of bur oak, but most of the sapling- or small pole-sized trunks were the understorey shrub, eastern hop hornbeam.

The second of these slides was a composite view of this bottomland portion of the loess hills forest with a large bur oak in center foreground with basswood off to its left and right and, indisguishable in the distant background, trees of green ash (Fraxinus pensylvanicaus), hackberry (Celtis occidentalis), and black walnut (Juglands nigra).

The understorey n both slides (and all the others in this series of photographs of bottomland and lower hill slopes) included common or stinging nettle (Urtica dioica), Pensylvania caric-sedge (Carex pensylvanica), bottlebrush (Hystrix patula), thimbleflower of wind flower (Anemone cylindrica), sweet cicey or sweet anise (Osmorhiza longistylis), prurple meadow-rue (Thalictrum dasycarpum). winter or snow trillium or dwarf white wake-robbin (Trillium nivale) uand the exotic forbs, motherwort (Leonurus cardiaca) and creeping Chaly (Glechoma hederaceae). Irregular and generally minor grasses included Canada or nodding wildrye and, still at very young growth stages, woodreed grass (Cinna arundinacea). There were various forbs that could not be identified at their very young growth stage at this poiint of the warm-growing season. Poison ivy (Rhus radicans=R. toxicodendron= Toxicodendron radicans) was a mid-storey shrub that grew into tree crowns and, thus, became part of the forest canopy.

Still in a loess hills 'holler"-Bur oak-basswood forest vegetation in the bottom of a "holler" (hollow), at base of a draw, in the Wester Loess Hills of the Missouri River Valley in northwest Iow. In the first slide the largest tree in center was a basswood as was its neighbor to the right while the tree to left o big basswood was a young hackberry. Smaller trunks to the rear were eastern hop hornbeam. The grasslike plant carpeting the ground with garceful, curving leaves in the foreground was Pensylvania caric-sedge. Behind were colonies of common or stinging nettle. Other forbs that could be identified this early in the warm-growing season included snow wake-robin, white snakeroot, thimbleflower or thimble wind flower, sweet cicey or sweet anise, purple meadow-rue, and the naturalized exotics, motherwort and creeping Charly. Grasses included bottlebrush, nodding wildrye, and woodreed grass. Poison ivy was common and in many instances had climbed into the tree tops.

The second slide included many of the same forbs as in the first slide and Pensylvania caric-sedge, but the feature of the second slide was a clear example of asexual reproduction, and the resulting growth habit, of basswood. The smaller, seecondary shoot to the immediate left of the main trunk had developed from the stump of the main bole. This morphological feature is a notable characteristic of basswood or Ameericcan linden. Production of such secondary trunks, ofter resulting in clumps of basswood (even of large trees), was commonplace in this loess hills fores,

Stone State Park, Plymouth County, Iowa. Mid- June, vernal aspect. FRES No. 15 (Oak-Hickory Forest and Woodland Ecosystem). No Kuchler unit for bur oak forest; closest was Bur Oak Savanna (unit 81 in Kuchler, 1964, unit 72 in .Garrison et al., 1977, including map). SAF 42 (Bur Oak). In Brown et al. (1998, p. 37) would be Quercus macrocarpa Association 122.11? (say 111) of Oak-Hickory Series 122.11 of Northeastern Deciduous Forest 122.1. Western Loess Hills Ecoregion 47m (Chapman et al., 2002; Omernik et al. Undated).

Burred, bassed, hacked, ashed, and blacked in the bottom- Still in the lower point of a "holler" the range vegetation of a bur oak-basswood forest that had developed in the Western Loess Hills of the Missorui River Valley of northwest Iowa supported numerous species of both woody and herbaceous plants.In the first slide a large (sawlog-size) bur oak framed the right side of this sylvan view while two somewhat smaller bur oaks were to the left and rear of the big leaning bur oak. Two large old-growth stage bur oaks were the "center of attention" in the second slide with a sapling-size eastern hop hornbean to left of the foremost bur oak. Indistinguishable tree species in the backgrounds of both slides included basswood, gren ash, black walnut, and hackberry.

Forbs made most of the herbaceous understorey with white snakeroot, stinging nettle, sweet cicey or sweet anise, dwarf white or snow wake-robin, and the exotic weed, motherwort being the major forbs that could be identified at this point in the warm growing season. Pensylvania caric-sedge was the main monocotyledon with the grass, bottlebrush, growing in a sparse but widely occurring local distribution.

There was limited seedling reproduction of bur oak and basswood, but most intermediate-size trees were hackberry as shown in the next two slide-caption set. Advance the projector please...

Bottomed out- Terminal points of ravines or draws in a bur oak-basswood forest that developed in the Loess Hills out of the Missouri River Valley in northwest Iowa. Big trees in foreground of both of these photographs were bur oak. Most of the sampling-size boles were eastern hop hornbeam (eg. trunks to immediate left of the big bur oak in first slide), though several of the small poles or large saplings were hackberry (Celtis occidentalis) such as the one in left forgeound of the first slide.Big tree in center of second slide was an immense bur oak as was the large sapling or small pole to its close left.

Tree species in the background of both slides besides burr oak included basswood (eg. four trunks in a clump in left background of first slide), green ash, and black walnut. Herbaceous species included forbs of common or stinging nettle, white snakeroot, sweet anise or sweet cicely, purple meadow-rue, snow wake-robin, and ther two naturalized exotic weeds, motherwortand creeping charly. The main grass in these two views was bottlebrush. There was more cover of Pensylvania caric-sedge than of grass. (Although it was late spring most grasses were still in vegetative stages and were not positively identifiable--except perhaps by local "experts"

"Hollered" out; back up the hill- Range vegetation of a bur oak-basswood forest on the toe slope of a hill in the Western Loess Hills on the upper Missouri River Valley in northwest Iowa. foot.The big trees in these two slides werre bur oak (three foremost trees in first photograph and two formost trees in second slide). Basswood was the second most abundant tree (eg. forked trunk or two trunks growing close together in center background of the second slide). Other, occasional trees were hackberry, green ash, and black walnut. Eastern hop hornbeam was the dominant shrub. Poison oak was commonplace often growing into tree tops.

The herbaceous layer or understorey consisted mostly of forb species including sweet cicely or sweet anise, white snakeroot, snow wake-robin, stinging or common nettle, purple meadow-rue, and two naturalized alien weeds, motherwort and creeping Chaly. Pensylvania caric-sedge was the most abundant monocotyledon with the grasses bottlebrush, woodreed grass, and Canada or nodding wildrye being more occassional in appearance. This was the major make-up of the vernal society.

Still going uphill- About mid-slope of a hill comprised of loess in the Western Loess Hills of northwest Iowa on which a bur oak-basswood forest had developed. In addition to the dominant bur oak (and locally co-dominant basswood or American linden) other trees included hackberry, green ash, black walnut The dominant shrub (sometimes, a small tree) was eastern hop hornbeamn. In the first slide the large trunk at right margin and the two large trunks in center midground were bur oak. The foremost trun at left foreground was a young pole of hackberry while the three large trees in right midground and background werre bur oak. Some bur oaks in this forest were senescing or even obviously reaching end of their lives (eg. tree to immediate left of the forked trunk bur oak in midground).

A developing species dynamic in this forest was the increased density and cover of young hackberry (Celtis occidentalis). The photographer did not see any hackberry seedlings, but there were a number of young sapling to pole-size hackberry trees.There were very few bur oak of the pole-size class yet there were bur oak seedlings that appeared adequate to perpetuate this dominant tree species. Absence of large adult hackberry coupled with presence of the pole-size/age class (as seen in the second slide) sugggested that hackberry was increasing and that this was a new development. In tolerance ratings hackberry is Intermediate to Tolerant which, depending on forest site is more tolerant than bur oak, but lower in tolerance than basswood. Was plant succession in this forest moving toward a stage in which hackberry would be a another major--even--dominant--tree species? What successional status is hackberry? Was hackberry more common in this forest without a history of recent fire, say, surface fire? Bur oak is quite tolerant of fire and hackberry much less so with studies having shown that hackberry decreased in bur oak savannahs following surface fires (Fire Effects Information System, U.s. Foreest Service, onine)..

The herbaceous understorey was composed primarily of forbs including snow or dwarf white wake-robin, sweet anise or sweet cisely, white snakeroot, stinging nettle, purple meadow-rue, and the ttwo exotic weds, motherwort and creeping Charly. The most abundant monocotyledon was Pensylvania cric-sedge; also, scattered plants of bottlebrush, nodding wildrye, and woodreed grass. This was the vernal society. Non-blooming forbs of the esstival and autumnal societies werre not identified.

Hopped up- Eastern or American hophornbeam (Ostrya virginiana) is an understorey shrub to small tree throughout most of the eastern decciduous from northeast Canada through the Greak lakes foress across to Wyoming and extendinf across the westerrn Florida Panhandle (Burns and Honkala, 1990). This refereence is an excellent source for details of this species which is one of the most tolerant (usually rated Very Tolerant) woody species in North America.

The exaample presented in this three-slide set was growing in a mesic oak-basswood forest that bordered on a tallgrass prairie in the loess hills of northwest Iowa.

Eatern hophornbean is monecious with male and female inflorescences typically found on the same branch. The female flower and fruit-bearing strcture resembles domestic hops (Humulus lupulus), hence part of the common name. The fruit of eastern hophornbeam is is a nut or nutlet enclosed inside a parchment-like sac. Nutlets (= nuts) serve as a source of mast for birds and smaller mammals. Ostrya is a member of the birch family (Betulaceae), coryloideae subfamily, Coryleae tribe. As with other members of the birch family the basic inflorescence unit is a cymule or minature cyme (Smith, 1977, ps. 98, 293), a clear example of which is featured in the third slide.

Sargent (1933, p. 203) termed the pistillate flower structure as an ament. (By the way, this timeless clasic should always be referred to in studying North American trees.)

In general all members of the birch family provide valuable browse for wildlife, especially the cervids, and, though less critically, for livestock including grass-feeders like cattle, horses, and mules. Obviously, hazel nuts are a highly esteemed mast for almost all animals, including man.

Stone State Park, Plymouth County, Iowa. Mid-June.

A doinant- Lower trunk of bur oak (Quercus macrocarpa) growing in a bottomland forest largely made up of bur oak, basswood or American linden, hackberry, black walnut, and white ash in the Loess Hills of northwest Iowa..

Stone State Forest, Plymouth County, Iowa. Mid-June.

An associate- Trunk of adult black walnut growing in a bottomland forest largely composed of bur oak, basswood, hackberry and white ash in the Loess Hills of northwest Iowa..

Stone State Forest, Plymouth County, Iowa. Mid-June.

Blooming like no tomorrow- American linden or basswood (Tilia americana) in full bloom. Lower limbs of tree growing in more-or-less full sun.

Cass County, North Dakota. Late June, first day of summer.

Leaves and flowers of basswood- Overall view of complete leaves laid over flowers (first slide) and details of inflorescence over leaves (second and third slides) of basswood. Adaxil (upper) surfaceLof leaves in first slide; abaxil (lower) surface of leaves in second and third slides.

Cass County, North Dakota. Late June, first day of summer.

Flowers of a a shade tree- Flowers of basswood or American linden produced (and presented) in full sun. Basswood. Although basswood is regarded as Tolerant, and can compete with the even more Tolerant sugr mapple (Acer ) due to extensive root system and plentiful sprouting (Burns and Honkala, 1990), it is commonly used as a shade tree in the Midwest as was the case for flowers shown here.

Cass County, North Dakota. Late June, first day of summer.

Spindly in the shade- Three views of a scrawny almost-shaded-out individual of Pensylvanica caric sedge (Carex pensylvanica) in the understorey of a basswood or American linden-bur oak-eastern hop hornbeam forest in the Loess Hills of northwest iowa. The successional status of this forest was unknown. This forest appeared to have developed on the rich, wind-deposited soil that had formerly supported a typical bluestem-dominated tallgrass prairie In turn, the status of the prairie was not known. Had the apparently preceding prairie been maintained by Indian-burning, geologicly recent wind disturbance and soil depositiion, or was it meterologically determined (including lightening-ignited fires) so as to be classic climax(=climatic climax)?

At any rate this member of the Eu carix subgenus was barel;y hanging in the shade of large haredwood trees that were also adapted to the deep soil of the phenomenal Loess Hills.

The neighboring fruiting bodies of the neighboring peppery milk-cap mushroom (Lactarius piperatus) were presented below.

Stone State Park, Plymouth County, Iowa. Mid-June, early bloom stage.

Brushed bottle- Bottlebrush (Hystrix patula) in the herbaceous understorey of a bottomland hackberry-bur oak-basswood forest that developed in the Loess Hills of northwest Iowa. The successioanal status of this forest was unknown. Tallgrass prairie apparently had been the vegetational community immediately preceding development of this mid-continent mixed hardwood forest. Bur oak forests and groves werre a common natural community in pre-whieman and early settlement times, but tallgrass prairie was even more common as the dominant vegetation of this region.

Was this forest the climax,climatic climex, for this bottomland site? Or could this forest only have developed with restricted fires and fire suppression by European settlers. Even if absence of fire permitted development on what otherwise have been tallgrass prairie, was that fire interval natural or the result of burning by non-native Indians who migraated over the Berring Land Bridge?

Presence of bottlebrush just deepened the matter of succesional status of this forest. Bottlebrush is typically a species of woodland or savanna and does not thrive on native prairie. The author did not encounter any bottlebrush on a climax tallgrass prairie (virgin sod) in this vicinity.

For now, bottlebrush (and the native hardwood trees) were/are here composing a forest that was typical of Central Lowlands hardwood forests.

Stone State Park, Plymouth County, Iowa. Mid-June, mid-bloom stage.

Bottled in the shade- Sexual shoot (first slide) and spike with flag leaf (second slide) olf bottlebrush growing in the shaded herbaceous understorey of a lowland hackberry-bur oak-bass or American linden forest in the Loess Hills of northwest Iowa.

Stone State Park, Plymouth County, Iowa. Mid-June, mid-bloom stage.

A oft-touted alien- Motherwort (Leonurus cardiaca) growing in the understorey of a hackberry-bur ak-green ash bottomland forest in the Loess Hills of northwestern Iowa. This member of the mint family (Labiatae; subfamily Lamioideae) is now a planetary wide forb. it has long been used as both home remedy as well as medicine by the mdeical professionss. Presence of this naturalized weed in the rich loess soil of this bottomland forest probably did not indicate anything in particular. It was well-represented in the understorey so it was shown for what is was worth.

Stone State Park, Plymouth County, Iowa. Mid-June, mid-bloom stage.

Another naturalized invder. Creeping Chaly (Glechoma hederaceae) was another Eurasian member of the mint family (Labiatae; subfamily Lamioideae) growing in the herbaceous layer of the understorey of a bottomland hackberry-bur 0ak-green ash forest in the Loess Hills of northwest Iowa. Creeping Charly is fairly invasive and this naturalized weed certainly unwelcome in this prairie forest.

Stone State Park, Plymouth County, Iowa. Mid-June, full-bloom stage.

Not so spicey,saussey, or sassy, but cicely- Sweet cicey or sweet anise (Osmorhiza longistylis), a memeber of the carrot or parsely family (Umbelliferae), is a widely though usually infrequent, forb in the understorey of deciduous forests in eastern and central North America. Your author has encountered this range forb from eastern Oklahoma to this one in a ;hardwood forest in the Loess Hills of northwest Iowa. These plants were under the shade of basswood and bur oak trees where their neighbors included the grass, bottlebrush, caric sedges, and intdoduced/naturalized weedy forbs.

Stone State Park, Plymouth County, Iowa. Mid-June, mid-bloom stage.

**Water Oak (Quercus nigra) Forests**

The first example of the water oak (Quercus nigra) forest cover type shown immediately below was in a commercial forest in the Big Thicket section of the Texas Pineywoods. This water oak forest vegetation was adjacent to loblolly pine stands and a forest dominated by loblolly pine, water oak, American holly both with a lower woody layer comprised primarily of yaupon or, often called, yaupon holly (Ilex vomitoria).

Water oak has been regarded as Intolerant as to tolerance and as a subclimax species that is quite susceptible to fire damage (Fowells, 1965, p. 630; Burns and Honkala, 1990, Vol. 2, p. 703). Thus while light surface fires tend to maintain pines like the associated loblolly pine, major fire damage as with crown fires would select for regeneration of water oak. In absence of fire plant succession would progress to a climax of hardwoods, which in the Big Thicket would commonly be American beech, southern magnolia, American holly, and climax oaks such as white oak.

169. Water oaks in the Pineywoods- Exterior view of a local stand of water oak growing on a flatland forest site that frequently ponded water. Loblolly pine were growing around perimeter of the water oak stand. Yaupon grew as widely scattered individuals while most of the ground layer was oak leaves with scattered plants of longleaf woodoats (Uniola sessifolia), cottongrass bulrush (Scirpus cyperinus), and green flat sedge (Cyperus virens). These species (from this locale) were featured below under the loblolly pine-water oak-American holly form or subtype of loblolly pine-hardwoods forest. The largest--and also the most scarce-- herbaceouss pecies was bentawn plumegrass (Erianthus contortus) which was also featured below.

Liberty County, Texas. February, late hibernal aspect. This is a component or subtype of the general hardwood-pine southern forest forest that has one of the southeastern yellow pines a dominant or, sometimes, an associate species with oaks, hickories, or even beech as the more common climatic dominant (in contrast to a fire-determined dominant). Overall this forest range vegetation would have to be included in FRES No. 13 (Loblolly-Shortleaf Pine Ecosystem) with K-101 (Oak-Hickory-Pine Forest) being the Kuchler equivalent listed thereunder. SAF 88 (Willow Oak-Water Oak-Diamondleaf [Laurel] Oak). Oak-Pine Series of Brown et al (1998) (but should be for Southeastern Deciduous and Evergreen Forest biotic community). South Central Plains- Flatwoods Ecoregion, 35f (Griffith et al., 2004).

Inside the water oaks- Interior of the local stand of water oak presented immediately above. This was a local consociation of Quercus nigra with a "broken" (widely scattered) population of yaupon holly and local herbaceous cover composed variously of longleaf woodoats, cottongrass or woolgrass bulrush, green flat sedge, and panicgrasses (Panicum spp.). This isolated water oak stand was adjacent to a mixed forest of loblolly pine, wter oak, and American holly (covered below).

Liberty County, Texas. February, late hibernal aspect. FRES No. 13 (Loblolly-Shortleaf Pine Ecosystem) with K-101 (Oak-Hickory-Pine Forest) being the Kuchler equivalent listed thereunder. SAF 88 (Willow Oak-Water Oak-Diamondleaf [Laurel] Oak). Oak-Pine Series of Brown et al (1998) (but should be for Southeastern Deciduous and Evergreen Forest biotic community). South Central Plains- Flatwoods Ecoregion, 35f (Griffith et al., 2004)..

170. One of the more common forms or manifestations of oak forest in the Pineywoods of Texas and Louisiana is the Palmetto-Oak Flats (Ajilvsgi, 1979, ps. 12-13) or, when expressed as to topographic-edaphic rather than botanical features, Clayey Wet Upland Depressions (Diggs et al., 2006, ps. 97-98). Ajilvsgi (1979, p. 12) described overcup oak and laurel oak as dominants whereas Diggs et al., (2006, p. 98) emphasized willow oak and green ash (Fraxinus pennsylvanica) as major plants of the larger tree species. The Society of American Foresters (Eyre, 1980, p. 63) described the willow oak-water oak-diamondleaf or laurel oak type (SRM 88) as developing on a topographic-soil moisture gradient intermediate between the swamp chestnut oak-cherrybark oak type (SRM 91) and the overcup oak-water hickory type (SRM 96) with dominance of SRM 88 tending to change to non-oak hard spceies like green ash under heavy logging or high-grading.

The photographs shown below were of a water oak-willow oak forest with a lower shrub layer made up almost exclusively of dwarf palmetto and a herbaceous layer(s) of sedges, rushes, bulrushes, and panicoid grasses. Views of the Oak-Palmetto Flats in these slides were presented so as to view this forest range vegetation going from exterior to deep interior as if the viewer were traveling to and then into it.

171. Coming onto the Oak-Palmetto Flats- Exterior view of an example of the willow oak-water oak-diamondleaf (laurel) oak type showing physiogonomy and overall species composition of this form of Pineywoods. Dominant species of this stand was water oak with willow (locally known as "pin" oak). Laurel oak was a distant third Quercus species. Blackgum or black tupelo (Nyssa sylvatica) was another associate tree species. The largest tree with the horizontal upper limb and fire-scarred basal trunk was an ancient water oak readily idetified by the sporadically scattered, prominent "warts" of bark. Loblolly pine was represented by one conspicuous tree in center midground. There were other infrequent loblolly pine throughout. Young trees grouped at right foreground were a mixture of water and willow oak and very black tupelo. Dwarf palmetto made up a lower shrub layer. Grassses and grasslike plants comprised one or two (rarely three) herbaceous layers in the forest understorey. Herbaceous plants were most common around perimeter of the forest vegetation. Individuals of broomsedge bluestem (Andropogon virginicus) were prominent in foreground understorey.

Hardin County, Texas. February, hibernal aspect. FRES No. 13 (Loblolly-Shortleaf Pine Ecosystem) with K-101 (Oak-Hickory-Pine Forest) being the Kuchler equivalent listed thereunder. SAF 88 (Willow Oak-Water Oak-Diamondleaf [Laurel] Oak). Oak-Pine Series of Brown et al (1998) (but should be for Southeastern Deciduous and Evergreen Forest biotic community). South Central Plains- Flatwoods Ecoregion, 35f (Griffith et al., 2004).

172. Edge of an Oak-Palmetto Flats forest range- Around perimeter of a stand of water and willow oak with dwarf palmetto were various local assemblages of herbaceous plants. The latter included cottongrass bulrush and miscellaneous sedges, both Carex and Cyperus species (eg. green flat sedge [C. virens]), along with panicgrasses, especially beaked panicgrass (Panicum anceps); paspalums like brownseed paspalum (Paspalum plicatulum), and both broomsedge and bushy bluestem. These latter two species are invaders. These same species also formed herbaceous strata beneath the oaks and pines though with less continuous cover and smaller plants, conditions likely resultant from fairly dense shade. Water and willow oaks are Intolerant species.

173. Into the Pineywoods flats we go- These three photographs were a pictorial "walk to the woods", a sequence of slides showing the range vegetation of a water oak-willow oak- loblolly pine-palmetto-herbaceous plants Pineywoods flats. Continually closer-in views allowed presentation of the herbaceous layer(s) of native vegetation that was better developed at outer edge of the forest stand. Some of the common herbaceous species of this vegetation were presented below in the section devoted to the loblolly pine cover type, specifically the loblolly pine-water oak-American holly form or subtype thereof. The smaller trees in foreground with unshed lower limbs (most of them still alive but senescing) were willow oak. Locals hereabouts apply the otherwise confusing and nonstandardized common name of "pin oak" to Quercus phellos. "Pin" in several oak species refers to any of the lower, usually dead, unshed limbs (ie. dying or dead limbs on species that do self-pruning, but instead become well-seasoned or preserved and, hence, persistent on the lower bole). There were a few scattered woody vines, the only one of which the author-photographer identified was rattan (= Alabama supplejack).

Once inside the Pineywoods flats the interior of the water oak-willow oak-dwarf palmetto-herbaceous range community revealed a "closer-in" view of plant species composition and the lower woody layer of palmetto and the local vertical zone of herbaceous species. Largest trunk was that of a young to mid-age water oak with bark characteristic of an immature tree. At this stage of maturity bark of water oak and willow oak is so similar as to be indistinguishable, thereby making reliance on leaves and buds necessary for definitive indetification. "Warty" bark on older water oak bark was just forming on this straight-trunked specimen, but some smaller water oaks had larger "warts".

Grass shoot (visible in both photographs) in front of this water oak was broomsedge bluestem, a common invader of Oak-Palmetto, which was common and conspicuous throughout this oak flats stand. Almost all herbaceous species were grasses or grass-like plants and, as this was dead of winter and this range had been grazed so that most species had to be identified by vegetative features, most herbs could not be identified by the author who was a "stranger to these parts". The tallest green herb was cottongrass bulrush (shown and described briefly below). There were no prominent forbs in this forest range vegetation. Dwarf palmetto comprised a single-species, lower, woody layer.

174. "Up-and-dicular" perspective of a Oak-Palmetto Flats- Structure and species composition of the water oak-willow oak-dominated Pineywoods flatwoods described under horizontal photographs above. Architecture of this stand was displayed to better advantage in these two photographs. Most hardwood trees were water oak and willow oak of sapling to small pole size. Those with persistent lower limbs were willow oak. There was an "occasional" black tupelo (also of sapling-pole size).

Cover and density of palmetto was shown to good advantage in the first of these two slides while the frequent openings within the palmetto that were populated by grasses and grasslike plants were evident in the second slide. Tree in left foreground with live lower limb was willow oak.

This stand was obviously a second-growth forest. A cohort of sapling to small pole size oaks had developed beneath larger, established (older) but very widely scattered, mature oaks of both species. Structure and, especially, botanical composition of this stand was typical of climax water oak-willow oak-laurel oak-palmetto vegetation. Both willow oak and water oak are classified as Intolerant and recruitment of these species had been possible under a mostly open sky (sparse canopy of oak and loblolly pine). Natural thinning of oaks had already commenced as evidenced by the dead toppled pole (visible in both photographs). This will undoubtedly continue resulting in more dead younger oaks and fewer, though larger, trees (fewer boles but more board foot/acre) and eventually greater oak crown cover (increased--though by no means closed--tree canopy).

The apparent dominant herbaceous species was cottongrass bulrush. Numerous individuals of broomsedge bluestem were conspicuous with their tannish yellow shoots dispersed among bulrush and other grasslike plants.

175. Closing, composite shot of Pineywoods Oak-Palmetto Flats- All-in-one shot of species composition and structure (architeture) the water oak-willow oak-loblolly pine-palmetto-cottongrass bulrush-broomsedge bluestem community featured above. All of these species except loblolly pine, which dominated (generally and/or locally) their respecive layers of vegetation, were visible (if not obvious). In addition, rattan (= Alabamas supplejack) was featured prominently growing up trunks of oaks in left midground. Almost all oak trunks of any age are hosts to various crustose lichen, at least on north and east exposure.

176. Water oak (Quercus nigra)- Upper trunk and crown of water oak showing leaves and bark of intermediate maturity. Older or most mature bark of water oak often forms wart-like raised areas (basal trunk and stump area). Houston County, Texas. March.

177. Watery preparation-Outer parts of longer branches of water oak at peak bloom stage. Most catkins were staminate, but both sexes of these unisexual flowers were present. Quercus species are monecious. This tree was preparing for fruit production. Freestone County, Texas. Late March.

178. Male flowers- Cluster of staminate catkins in water oak. Freestone County, Texas. Late March.

179. Female flowers- Pistillate catkins of water oak showing a leader with several catkins (first slide) and detailed view of some small clusters of these catkins (second slide). Freestone County, Texas. Late March.

180. Watery production- Leader of water oak bearing a heavy yield of acorns. Water oak is in the red oak subgenus (Erythrobalanus) the taxon within which two years (growing seasons) are required for growth and maturity of individual acorns. Freestone County, Texas. Early September.

181. Water oak production up close- Details of leaves and acorns of water oak. Water oak leaves provide a textbook example of the spatulate (spatula- or spoon-shape) . leaf shape. From the perspective of Range Management and Wildlife Management both leaves and acorns are sources of agricultural production because foliage and fruit are feed for livestock and wildlife (browse and mast, respectively)

Freestone County, Texas. Early September.

182. Dwarf palmetto, blue palmetto, swamp palmetto, dwarf palm, blue palm, etc. (Sabal minor)- Large, mature swamp palmetto with previous season's floral stalk and spent inflorescence. This true palm is most commonly acaulescent (lacking a trunk or bole) though sometimes there are individuals that have a single, short woody stalk which would "pass for" a trunk. The shoot or stem does not branch and is characterized as woody or pithy in nature.

The speciment portrayed here was growing in the water oak-willow oak-lobollly pine-palmetto-cottongrass bulrush-broomsedge stand featured above. Hardin County, Texas, February.

Savanna of Oak-Hickory Forest and Tallgrass Prairie

The tallgrass prairie-hardwood forest savanna or transition was given a chapter of its own in this publication entitled, Tallgrass Savvanna, plus a section on Prairie Peninsulac in the chapter, Tallgrass Prairie (Interior). One photograph and caption was included at this point to highlight locations for these important deciduous forest and eastern prairie grasslands.

183. Oak-hickory forest and savanna— This is the widespread transition zone or intermediate community type between actual oak-hickory tallgrass prairie understory savanna and the western edge of the oak-hickory forest proper.Post oak and black hickory dominate the tree layer while black and red oak are associated species. Understory is primarily nodding or Canada wildrye and purpletop (Tridens flavus). Virginia creeper covers much of the understory and climbs into tree tops. Blackberry, buckbrush, Mayapple, and black-eyed susan dominate various microsites depending on cover of tree canopy. Chert savanna-chert forest composite type with fire determining which form prevails. June, late vernal aspect.

FRES No. 15 (Oak-Hickory Ecosystem). K-73 (Mosaic of Bluestem Prairie [K-66] and Oak-Hickory Forest [K-91]). SAF 52 (White Oak-Black Oak-Northern Red Oak) but with black hickory more than black oak; SRM 801 (Dry Savanna). Oak-H:ickory Series of Brown et al. (1998).

Dominant, Associate, Widespread, and Just Plain Interesting Plants
of the Central and Southern Forests

184. Composite view of Oak-Hickory Forest- Tree on left is pignut or bitternut hickory, the forked trunks with burl on left trunk is black cherry, a young pignut hickory to its immediate right, and the two larger white-barked trunks in background visible between the hickory and cherry are post oaks. The barely detectable short shrub dominating the understory is buckbrush which in this winter season has shed its fruit. Hibernal aspect .

Ottawa County, Oklahoma. Hibernal aspect, Late December. FRES No. 15 (Oak-Hickory Forest Ecosystem), K-91 (Oak-Hickory Forest), SAF 40 (Post Oak-Blackjack Oak). Oak-Hickory Series of Brown et al. (1998). Ozark Highlands- Springfield Plateau Ecoregion, 39a (Woods et al., 2005).

185. Cherries in the woods- Leaves and ripening fruit of black cherry (Prunus serotina). The fruit type of Prunus species is pome. Black cherry is the source of commercial cherry wood, one of the most beautiful of all North Americn hardwoods. Black cherry is not a domiinant or even associate tree species in climax oak-hickory forests, but in absence of fire it increases quickly and can overwhelm the climax dominant and associate oak and hickory species.

Ottawa County, Oklahoma. Late June.

186. Fruit of buckbrush or coralberry (Symphoricarpos orbiculatus)- This fleshy fruit is widely held to be valuable for bobwhite quail, squirrels, and rabbits. It is perhaps the most dominant species of the lower shrub layer (taller shrubs like dogwood, persimmon, sassafras, and redbud being local dominants of the taller shrub layer). Ottawa County, Oklahoma. Early December (and fruits may be shed within the month or persist on twigs in dried form until spring depending on the year).

187. Flowers of flowering dogwood (Cornus florida)- This is probably the most widespread understorey shrub or small tree in the oak-hickory forest forms and, therefore, is typically the dominant of the lower woody plant canopy. In the spring flowering dogwood (often accompanied by redbud) turns the dark, drab-colored, bare woods into a colorful botanical banner announcing start of another growing season. This species with it's delightful spring and, as shown immediately below, fall display is the State Tree of Missouri. Ozark Plateau. Newton County, Missouri. April.

188. Leaves and mature fruit of flowering dogwood in fall coloration- It is an age-old argument as to whether the spring or autumn is the more colorful in the deciduous forests of eastern North America. The argument cannot be resolved by admiring the flowering dogwood which contributes to the beauty of the timberlands in both seasons. The fruit is a major food source for wild turkey (Meleagris gallopavo) and bobwhite quail (Colinus virginanus), especially in the south as in the Ozark Mountains, while the twigs are important browse for white-tailed deer (Odocoileus virginianus). Indians had several uses for this shrub (eg. dyes, herbal remedies).The hard, tough, tight-grained wood has many non-construction uses.

Newton County, Missouri. October.

189. Shadbush or eastern or downy serviceberry (Amelanchier arborea)- Another shrub of the oak-hickory-- and general eastern deciduous-- forest is downy serviceberry. The common name of shadbush comers from the hill folk who noted that blooming of this species often coincided with the spring runs of shad (Alosa spp.). Downy serviceberry is often confused with flowering dogwood because the flowering periods of these two species often overlap and that of one species may precede or lag behind the other depending on conditions in any one spring. (Dogwood gets all the credit by the way.)

Serviceberry is one of the many members of the rose family which is the single most important family of range browse plants in North America. Amelanchier species are in the Pomoideae, the pome fruits subfamily, of Rosaceae. Shadbush undoubtedly provides some browse and the fruits are eaten by birds and furbearers, but it is not common enough to be a major feed plant.

The bluffs of Modoc Creek, Ottawa County, Oklahoma. April.

190. Downy serviceberry in full bloom- In the opinion of your author when this species is flowering it is often the most striking and showy shrub in the oak-hickory forest. Much of the enjoyment of the spring blooming in the hills is due to serviceberry and not flowering dogwood, but a human population of predominantly city dudes does not know the difference and just calls everything other than redbud a "dogwood". Ottawa County, Oklahoma. April.

191. Flowering shoot tip of downy serviceberry- The inflorescence and two newly emergent leaves of shadbush or eastern serviceberry. Ottawa County, Oklahoma. April.

192. Goatsbeard or Goat's Beard (Aruncus dioicus var. pubescens= A. pubescens)- Goatsbeard is another striking member of the Rosaceae. It is far from common in the oak-hickory forest, but when it is encountered it causes the most hill-hardened hillbilly to pause and "take a gander". Aruncus literally means "goat's beard" and according to various manuals this name can be traced to Pliny and later applications to Eurasian species of this genus. This North American shrub has a range from the extreme northeastern part of the continent south to Alabama and west to Oklahoma.

Springfield Plateau section of Ozark Plateau; base of limestone hill in Newton County, Missouri. June.

193. Inflorescence of Goat's Beard- Goats's Beard is a dioecious, but the flower clusters are similar for both sexes. Newton County, Missouri. June.

The next series of eight slide-caption units were of the same plants of goat's beard introduced in the preceding two slide-caption sets except taken 25 years after the first slides. This group of several plants of the dioecious member of the spirea subfamily (Spiraeeoideae) of the rose family (Rosaceae) were growing on an extremely steep bank were free-ranging white-tailed deer (Odocoileus virginianus) and the neighbors Angora goats (Capra hircus) could not get to them. (Anyone who knows goats will know that this local home for goat's beard was about as inaccessable as a place could be to be where goats could not get to them.)

194. Separate sexes- Two slides of the separate sexes in goat'sbeard. This dioecious species has male and female plants, at least in most cases. In the first slide male plants were right and female plants were on the left. In the second slide of male plants were on the left and female plants were on the right.

These plants were growing at edge of a black oak forest in the western Ozark (Springfield) Plateau.

Newton County, Missouri. Mid-June; peak bloom phenological stage.

195. Boys on parade- Sexual leaders (blooming shoots) of the dioecious goat's beard, shrub in the spirea subfamily of the rose family growing on a steep hillside at edge of a black oak forest in the Ozark (Springfield) Plateau.