Plant Communities of the Midwest: Classification in an Ecological Context. (Books).
The Nature Conservancy was born in science, sired by Victor E. Shelford out of the Ecological Society of America. The scientific connection had grown tenuous by the 1960s, and the organization wisely hired a full-time science advisor, Robert Jenkins. One of his most important initiatives was a series of inventories of natural features, eventually one in every state, called the Natural Heritage Network.
By 2000, the Nature Conservancy had spun off the Natural Heritage programs into a separate organization called the Association for Biodiversity Information (ABI). This is the organization that has published Plant Communities of the Midwest, making use of Natural Heritage data from a 12-state area shaped like a wedge running from North and South Dakota, Nebraska, and Kansas to Ohio, the point. Don Faber-Langendoen, senior ecologist with the ABI, is the editor of this effort; 23 contributors are listed, employees of the ABI or of the state Natural Heritage programs.
The 61-page main report includes sections describing how this treatment of Midwest plant communities came about, descriptions of what are conceived to be the ecological regions of the Midwest (Great Plains, Prairie Parkland, Eastern Dry Deciduous Forest, Eastern Moist Deciduous Forest, and Laurentian Mixed Forests), some information on the U. S. National Vegetation Classification (USNVC) system, and a listing of the 588 plant communities (termed "associations" in the USNVC) to be found in the Midwest. These 588 plant communities are aggregated into 15 ecological groups, such as acid peatlands, wooded swamps and floodplains, rocky uplands, and prairies/ grasslands. "Ecological group" is not a part of the USNVC. In fact, after describing the six-level hierarchy, from Class to Association, designed to be applicable anywhere in the world, or perhaps the universe, this publication leaves the USNVC behind, to our benefit.
The main report also provides 10 color plates, each with 4 to 7 photographs showing associations illustrative of the 15 ecological groups. The photographs (and the reproduction) are more than adequate to give an idea of the look of the land and vegetation. It's true, and unavoidable at this scale, that many of the herbaceous-dominated communities look alike except for having different colored flowers.
For most users of this work, the importance of the main report will be to provide context for the 705-page appendix. This is where the great utility of the work lies. The appendix, Plant Community (Association) Descriptions, devotes a page to each of the 588 plant communities. Each page includes sections as follows: a description of the vegetation features plus brief notes on soils and natural disturbance regimes; a comments section that gives pointers on separating this community from related ones; conservation rank using the Natural Heritage global system running from G1 (globally imperiled) to G5 (secure) and also providing state rankings (S1-S5); geographical distribution of the community; and synonymy.
Synonymy includes names used by any Heritage programs where the name deviates and also names used by other students of the vegetation type. For example, the Beech-Oak-Red Maple Flatwoods of this work has been called Bluegrass Till Plain Flatwoods in Indiana, and in Ohio, D. M. Anderson termed something like it the Beech-White Oak Associes.
The information given here on the geographical distribution of closely related communities and variation within them has been unavailable for most communities before. This is perhaps the most important scientific justification for the work.
Community classification and nomenclature formed an important component of ecology until past the middle of the twentieth century. The appropriate basis for classification was debated, including the question of whether communities have an objective reality. The individualistic view of vegetation, generally identified with H. A. Gleason, suggested not. John T. Curtis used Gleason's idea as the basis for his studies summarized in The Vegetation of Wisconsin (University of Wisconsin Press, 1959). Curtis wrote that the floristic composition of vegetation "gradually changes along an environmental gradient--termed a 'vegetational continuum'--to emphasize the fact that no discrete divisions, entities, or other natural discontinuities are present." Having reached this conclusion, Curtis then divided the vegetation of the state into 34 commonsensical communities and devoted the rest of the book to discussions of them.
The mainstream of ecology bypassed community classification in the later decades of the twentieth century. This doesn't mean that the debates between communities vs. continuum or integrated communities vs. the individualistic view were settled. Most ecologists just found other areas of research and argument more interesting.
Nevertheless, delineation of communities is valuable for several purposes. One important one is as a framework for land conservation. Within the Natural Heritage Network, such work continued along its own side channel mostly unconnected with academic research in ecology, from the 1970s to the end of the twentieth century.
The present work is a product of that side channel. I'd judge that Curtis's work--not his continuum ideas but his pragmatic community classification--is the main philosophical basis for the approach this book uses. I know that some of the practitioners that contributed to the community delineations were explicitly aware of Curtis. Perhaps others absorbed it at second or third hand.
Curtis aside, this work seems to have little connection with any preceding thought about plant communities, though many of the ideas are identical to older ones. But the absence of historical continuity is nor unusual for ecology, where reinvention of ideas given new names is almost a distinguishing feature.
Most of the ecologists who identified biotic communities in earlier times-- Clements, Shelford, Weaver, Vestal, Cowles, and Braun--would have to be considered lumpers when judged by the classification produced here. Curtis, I mentioned, recognized 34 communities for Wisconsin. This work recognizes 150. But both Minnesota and Michigan have more--170 and 185.
Splitting is coming back in taxonomy. There are now three species of Scrub Jay, Rose-breasted and Black-headed Grosbeaks really are different, and what used to be the Solitary Vireo is actually three species. Just so, for plant communities. The narrow communities recognized in this book exist, and a study of them would have something useful to tell us about interrelations of community, environment, and plant dispersal.
Recognizing the fine distinctions may have even greater importance for conservation practice. If all the wet meadows of the Midwest belonged to one community, someone might argue that we could preserve one example, a big one, say, in southern Minnesota, and be done with wet meadows. If instead there are a dozen wet meadow communities, we need at least to preserve one or more good examples of every type.
The CD that's included with the main report includes the Appendix, the main report, and also individual state subsets of the plant community pages. A plastic-bound printed version of the Appendix is available for $57 plus shipping. For serious users, it is well worth the money; sliding back and forth among the computer images of 700 pages to make necessary comparisons is worth avoiding. It would, of course, be possible to print the whole thing out from the CD or even from the Web site. The current Web site is <www.natureserve.org>. Only months after the publication of this book, the Association for Biodiversity Information changed its name; it's now NatureServe.
This book, the main report but especially the Appendix, will be indispensable for any person or organization dedicated to preserving land and biodiversity in the Midwest. Every local land trust should own a copy, and if they have no staff member with the background in ecology and taxonomy to use it, they should hire one. Midwest ecologists, taxonomists, and those geographers that have begun to tackle natural landscape issues will find uses for it in teaching and research.
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|Article Type:||Book Review|
|Date:||Jan 1, 2002|
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