Vegetation

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Vegetation: Climax or Potential Natural 

The range types in the collection were, as best determined from the sources  cited, the potential natural vegetation (usually the climax vegetation). Some of these climax range types may be the climax as originally envisioned by Frederic Clements to whom climax equaled climatic climax (= regional climax, zonal climax, formation all of which were synonyms in Clements monoclimax theory). Other vegetation more clearly fit the conditions and categories of edaphic, topographic, pyric, etc. climaxes of the polyclimax view of George Nichols and Arthur Tansley or the climax pattern form envisioned by Robert Whittaker. In a few instances the vegetation was on habitats like immature soils, unstable land, avalanche paths, etc. that by definition could not yet reach climax (eg. most authorities have implied that climax vegetation requires mature soils or soils in equilibrium with prevailing climate and other soil-formation factors). These "immature" or subclimax plant communities that appeared to be (or that were recognized in the literature as) at the maximum possible state of development for the existing environment (ie. the vegetation was in dynamic equilibrium at the highest successional state possible) fit the criteria of potential natural vegetation. Whether climax (by whatever determining factors or theory) or, if seral, natural potential below climax, the plant community shown was the highest successional expression of vegetation possible for that site as it existed in the absence of abnormal disturbance. 

As best determined from the published authorities, the range vegetation pictured was either climax or the highest seral stage of vegetation possible for that habitat (range site) without deterioration. It was the plant community that was described as representative of the virgin vegetation, the pre-Columbian vegetation. Vegetation had not departed from the natural potential. Seral stages produced by overgrazing, plowing, underburning, drainage, flooding, or other anthropogenic disturbances were not included except for examples of 1) transitory forest range (eg. range could not exist on some of the southern pine types except as seral vegetation) and of 2) reseeded, introduced range types as defined above. A few examples of vegetation that existed below natural potential as a result of natural perturbations (eg. gopher eskers) were included to illustrate plant succession and the natural landscape mosaic pattern that existed due to such naturally occurring departures from climax or potential natural vegetation. 

Successional status could not be established definitively for some range cover types that were composed of both herbaceous and shrub species. Such vegetation appeared on the ground and in the literature as a veritable “no man’s land” of competition among those plants and among opinions of human “experts” as to dominance and community composition. These native plant communities were undoubtedly savannas before God (and essences like fire) shared the land with Adam. God alone knows the proportions of woody plants and grass in the climax Rio Grande Plains “brush country” and shinnery oak range types. Therefore  assertions of  “natural” or “ecological potential” for any given “patch” pictured were subject to challenge. Photographs of these range types included those species which most authorities have determined to be dominants and associates among shrubs and among herbs. Relative proportions of these recognized major native species, and of shrubs vs. herbs (mostly grasses), in pre-European vegetation and present potential natural vegetation (not necessarily synonymous) is the source of debate. While photographed vegetation of these cover types included climax species these may or may not have been in the same or roughly equivalent proportions as in climax (or current potential natural) vegetation. Vegetation was typical of range plant communities on the best managed commercial ranches and experimental ranges. Anyway, photographed examples of these cover types fell under the SRM/SAF qualifier of “present” or “existing” vegetation.      

Forest vegetation was either virgin forest at the old-growth stage; second-, third-, etc. growth-forests but with species composition more or less that of climax vegetation; or seral stages of transitory range (ie. exceptions to climax or near-climax vegetation were forest communities usable as range— existing as range cover types— only at successional stages below climax or natural potential). 

Community structure and species composition of the range vegetation was compared to that described in the ecological literature with priority given to the “classic” works by the “master” ecologists (those that withstood the ravages of fad, fashion, and time and who stood against publication politics and “publish-or-perish” pressure for potboiler mediocrity).  

Classification and description of vegetation and the end-point of vegetation development are (and inherently will probably always be) subject to interpretation. Iinterpretations of American (North, South, and Central) vegetation that existed prior to influences of European man--what has traditionally been described or entitled as native or natural vegetation--has varied among ecologists and related practitioners (rangemen, foresters, wildlifers) depending on numerous related variables. These include doctrines ("dogma") regarding succession and role of factors (eg. climate, soil, pysiographic features) on development of biological communities, philosophical (even political) viewpoints, definitional and conceptional meanings with regard to anthropogenic impacts in general as well as prevailing scientific views from related fields like those in the human social sciences (eg. Anthropology, Sociology), earth sciences (eg. Physical Geology, Climatology), and life sciences (including those that form hybrids with Vegetation Science such as Evolutionary Ecology).

These ideas (including their attendant biases) have varied over time with certain perspectives gaining and losing, then regaining and relosing in cycles of revisionism with corresponding changes in credability, popular standing, and active investigation within the politic-socio-economic tenor of the times. This included perspectives (both scientific and popular cultural views) with regard to technologically undeveloped peoples (ie. primitive man), including impact on their habitat, which have fluctuated from Rosseau's Noble Savage ("original" or "natural" man) to Hobbs' "state of Nature" in which human life was "solitary, poor, nasty, brutish, and short" (compared by Hacker, 1961). There have been periodic re-evaluations of the revisionist appraisals of original conclusions. The Myth of the Noble Savage by Ellingson (2001) is one such example.

A recent trend in this area of scholarship has been to re-evaluate the role of aboriginal man on his natural environment, including vegetation, soils, and even land forms. Several well-researched publications appeared that were concerned with various impacts of American aborigines (American Indians) on the pre-Columbian (pre-European) abiotic-biotic environment of the Americas. In other words, these were evaluations of the "state of Nature", "natural world", "Mother Nature", "balance of Nature", etc.in the Americas before and then after arrival of the first humans up to (at) the time European man arrived. These studies and summaries of studies dealt with (attempted to compare) the nature of the "natural" Americas prior to any human role and then after the earliest group of Americans had developed their civilizations up to the time they were encountered by European explorers. In these evalutations (and subsequent symposia and popular press publications based thereon) anthropogenic changes on natural--pre-human--land and water (flora and fauna, soils, streams, terrain) by aborigines (Indians) was compared to subsequent changes in post-Columbian time of human occupation. Examples of this genre of comparisons of Indian vs. European changes included those by Whitney (1994), Kay and Simmons (2002), and Mann (2005). Some of these works such as those by Mann (2005) or Kay and Simmons (2002 )were based more on conclusions determined by anthropological-archeological approaches whereas others like Whitney (1994) were based more on changes wrought by Europeans as compaed to estimates of pre-Columbian ecological states.

Additional recent scholarship has centered on influence of aboriginal man on natural landscapes and ecosystems (or, same thing, landscapes and ecosystems as modified by pre-industrial man) from the perspective of one tool (or simple combinations of tools) used by these early American peoples. Role of aboriginal use of fire in the Americas have been one of the more prominent of these sorts of reports with two of these recommended by this author being that edited by Vale ((2002) and the posthumerously published classic work of Stewart (2002). Effects of American Indians on plants, animals, soils, etc. has been a long-standing topic of research, often in conjuction with the general subject of frontier history. One example of earlier research concerning aboriginal impacts on the Amerian landscape included a detailed analysis of corn (Zea mays) production by Indians in the Upper Missouri Valley (Will and Hyde, 1917).

Any paleohistoric assessment of role and impacts of American Indians on the pre-Columbian (or general pre-European) "state of Nature", including biological communities and especially native vegetation, must distinguish between culturally and technologically advanced civilizations like Maya, Inca, Aztec, and Anasazi contasted with aboriginal groups that were in effect of the Neolithic hunther-gatherer stage (eg. Indian tribes of the Plains and Intermountain West of North America). Certain aboriginal peoples in the Americas had domesticated numerous plants including maize or corn, potato (Solanum tuberosum), tobacco (Nicotiana tobacum), cotton (Gossypium hirsutum, G. barbadense), pumpkins and squash (Cucurbita spp.), and various beans (Phaseolus spp.) far in advance of Columbus' voyages. The famed Spanish explorer lay claim to new plant species as well as new lands thereby causing a cultural revolution aroung the globe (Weatherford, 1990). Indian domestication of animals was much less impressive with a notable exception especially pertinent to Wildlife and Range Management being the turkey (Meleagris gallopavo) (Dickson, 1992, ps. 7-8, 45).

Impact of pre-Columbian Indians on animals was far greater through hunting, fishing, and trapping that resulted in what various researchers, following a hypothesis by Paul Martin (1967), described as Pleistocene Overkill (see reviews in Kay and Simmons, 2002). The idea or working hypothesis of prehistoric anthropogenic extinctions of many animal species thruough overhunting, -trapping, and -fishing during the late Quarternary by Paleo-Indians , Late Stone Age man in the Americas, has gained a substantial following based on paleontological standards and analysis, including physical archaeological evidence. Interested students can find a solid beginning bibliography in the literature cited in Kay and Simmons (2002).

In general, research into impact of American Indians on vegetation (and soils, wildlife, fish, waters) has shown that these peoples had impacts varying from basically little or no influence to those which totally resonstituted or restructered the pre-human environment. Relatively large fields of corn or maize replacing native grasslands and forests was one such change. Conversion of prairies and deciduous forests into corn fields was, obviously, greatly expanded by the white man equipped with steel axes and plows, but such type conversions (one example of Clement's disturbance climax) merely followed a form of agriculture learned by Europeans from their soon-to-be-dispossed Indian predecessors and teachers. Again, it must always be born in mind that American Indians varied from the advanced cultures of the Aztec, Inka (Inca), and Maya civilizations to the transported partial Neolithic culture of the Plains tribes. There were corresponding variations in human impact on the natural environment (including vegetation).

Even with reappraisals of aboriginal man in the Americas and subsequent assignment of considerably more credit for prehistoric manipulation and alteration of terrestrial and aquatic ecosystems than that extended by pioneer ecologists like Clements, Weaver, and Shelford it remains axiomatic that Indian impacts were generally less--considerably less--than that of the white man. The greater extent of technological advancement of European man when compared to that of the red man need not be extended beyond steel vs. stone axes, metal vs. bone or wood plows, guns and gunpowder vs. bow and arrow or spear, and domesticated ungulates vs. wildlife and Indian dogs. If to that rudimentary list there be added fuel-powered marvels of transportation (even use of livestock as beasts of burden dwarfed the Indians' dog-powered travois), construction of concrete multi-prupose dams, and mastery of the nuclear-capacity to incenerate Earth it becomes self-evident that the role in changing pre-human Nature was immensely greater in the instance of late-arrival Europeans than for the already present Mongoloid immigrants named Indians by those who summarily displaced them. Only in use of fire on the land (vs. in engines and bombs) could Indians be viewed as on par or superior to that of European peoples, and it is possible (if not highly likely) that efforts at total exclusion of fire from forests and ranges by the latter, misguided and disasterous though it has been, had more impact on American landscapes than the wiser and better use of fire by the red man.

In regards to anthropogenic effects on plant life in the Americas it should be noted that there is little evidence for human -caused extinctions of plant species. Indians clearly modified the vegetation (natural vegetation?) from what it was prior to their management, but even human extinction of animals (megafauna and/or the little guys) probably did not have as much lasting impact as nearly universal plowing of prairies, cut-and-run logging, and introduction of livestock with widespread overgrazing of ranges. European man also profoundly modifed existing vegetation through introduction of almost countless species of alien weeds and arthropods as well as causing or, at least, contributing to extinction--wholesale or mesoscale--of plant species. This included notable community dominants through introduction of such disease organisms as white pine blister rust (Cronartium ribicola= Peridermium strobi in the pine phase of life cycle), chestnut blight fungus (Endothia parasitica), and Dutch elm disease (Ceratocystis ulmi= Ceratostomella ulmi).

Incidence of European-introduced diseases provides the most clinching argument on role of white vs. red man with regard to impact on the pre-human vegetation. The single greatest factor in displacement (genocide) of American Indians by the white race was of course the European introduction of disease pathogens to the Americas, germs to which the Indians had almost no natural resistance. Most catastrophic in this regard was smallpox (a poxvirus: Variola major= Orthopoxvirus major). There were also epidemics and mass dieoffs among the aborigines from alien bacterial diseases, in particular Bubonic Plague (Pasteurella pestis= Yersinia pestis) and cholera (Vibrio cholerae). European immigrants also introduced major animal disease pathogens into the Americas that periodically wracked havoc in wildlife populations. Foot and mouth disease (Aphthovirus sp. generally designated as Foot and Mouth Disease Virus)and Bubonic Plague were notable among these. Given that European people essentially annilated the red race, especially from North America, it follows that the many and manifold influence of the Indians were, with some notable exceptions like Pleistocene Overkill and domestication of corn (maize), largely negated. From this perspective, the model of pre-Columbian potential natural or climax vegetation and best estimates thereof have validity and value as the baselines from which to describe, quantify, and evaluate range vegetation.

In summary, including recent studies of aboriginal impacts in the Americas, it seems that Indians did have the means (the ability or capacity) to highly modify nature, including natural vegetation, to meet their needs. It also appears that these Indian forms of agriculture, ranging from simple hunting and gathering to intensive cropping, that in some instances dwarfed that of the white man (eg. the miraculous breeding of the species, Z. mays) were at least as sustainable--probably much more so--than many of those of the white man. In most instances though it still appears that white man had more impact on vegetation. None of this, however, denies or in any way diminishes the concept of vegetational dynamics with its plant succession terminating in a climax or potential natural vegetation.The scientifically proven fact that American Indians highly modified the natural plant life of the American continents to better meet their needs only serves to further prove the ecological reality of vegetation (plant community) development with the sere moving to a more-or-less stable stage in dynamic equilibrium with its prevailing abiotic and biotic factors (ie. to a climax or natural terminus).

Perhaps the more relevant state of vegetation in the Americas from perspective of Forestry and Range Management would be pre-human and not pre-Columbian potential natural vegetation. That hypothetical state of native vegetation cannot be determined retroactively (ie. theoretically reconstructed). Vegetation scientists cannot map, analyze, etc. pre-human (ie. completely "natural") vegetation in the Americas because Indians had already been here for thousands of years before land surveyors, explorers, ecologists, paleontologists, etc. came on the scene. Pre-Columbian potential natural (= climax) vegetation is the closest "state of Nature's plant communities" that modern man can estimate for pruposes of vegetation mapping and other forms of inventory and assessment.

In final analysis, the designation and applications of vegetation that has been--as best as could be determined-- designated as pre-Columbian plant communities (including both seral and climax or potential natural) will always remain a valid benchmark. This includes such management and use designations as forest and rangeland cover (= dominance) types that are usually though not always estimations as to potential terminus of plant succession on specific groups of forest and range sites (ie. development of natural vegetation to its end point of dynamic equilibrium or advance of the series of plant communities on seres in absence of disturbances so severe as to drastically alter the site potential or, same thing, the potential endpoint of the sere).

The vegetation featured in this publication was, with a few exceptions, the climax or potential natural vegetation useful as native grazing lands. These native or, in some cases, naturalized plant communities constituted range, the major kinds of which were organized and described herein according to recognized units known as forest or rangeland cover (= dominance) types (Eyre, 1980; Shiflet, 1994). Vegetation classification units from other systems such as Forest and Rangeland Ecosytems (Garrison et al., 1977), biotic communities (Brown et al., 1998), and ecoregions (especially at Level III) of various agencies or bureaus were used when available and/or appropriate.