Grassland Dynamics: Long-term Ecological Research in Tallgrass Prairie. Knapp, A.K., J. M. Briggs, D.C. Hartnett and S. L. Collins; eds. 1998. ISBN 0-19-511486-8 (cloth US$65.00) 364 pp, 2 plates. Oxford University Press, 198 Madison Ave., New York, New York 10016.
"Grassland Dynamics", is the first book in the Long-Term Ecological Network Series from Oxford University Press to focus on long term ecological research sites (LTER). This book showcases the ecological discoveries made at Konza Prairie Natural Research Area in Kansas since the institution of LTER site there in 1980: Konza is one of the original six sites. The book is appropriately dedicated to the memory of Dr. Lloyd C. Hulbert who conceived of the landscape scale experimental design at Konza long before the IBP and LTER programs. It is organized into an introduction and five sections that describe the physical environment, terrestrial populations and communities, hydrology and aquatic ecology, ecosystem and landscape analysis, and lastly a look toward the future. All chapters end in a summary. The scope and message is broader than that of the1990 book, "Fire in North American Tallgrass Prairies", by Scott Collins and Linda L. Wallace.
The central theme is that prairie is primarily a non-equilibrium system where changes in fire, grazing and climate over the years bring about a switching among limiting factors that alter the diversity, composition and production of the terrestrial and aquatic ecosystems. This theme represents a developing paradigm shift in ecology. The second theme is the complexity of ecological interactions: "that indirect effects are pervasive and important". The editors and authors make a convincing case for these themes throughout the book and in the final chapter. Surprising non-equilibrium dynamics are illustrated by the fact that aboveground net primary productivity (ANPP) is not positively correlated with nitrogen availability. Instead, it is controlled by switching among alternative limiting factors: light limits production in the absence of fire irrespective of nitrogen levels and nitrogen and water are more important in frequently burned prairie. In addition, Gray et al. (Chapters 10 and 11) show that the dynamics in the prairie reaches and gallery forests of the stream drainage system are driven by extreme events (drought or floods) and that these systems a largely oligotrophic because of the tight retention of nutrients by the prairies.
Although all chapters are well written and engaging, several stood out as my favorites. Hayden (Chapter 2) summarizes the literature concerning the climatic controls on the distribution of prairies in North America. In a fascinating analysis of a regional flora and fauna assemblage matrices across the central U.S., he shows that species assemblages correspond well with regions defined by major climatic frontal boundaries. Kaufman et al. (Chapter 8) summarizes the research on mammals, birds, and grasshoppers, show the individuality of species response to fire, structure, grazing, season and climate. He then relates the results to prairie management. Collins and Steinauer (Chapter 9) relate how fire and herbivory by bison, as disturbances, influence community diversity and species interactions. I was disappointed not to see here and in other chapters a discussion of how species interactions and nutrient dynamics might differ between Konza and prairies that are more alpha diversity rich. Briggs et al.(Chapter 15) use GIS applications to examine historic changes in the landscape, model spatial components of temporal change in ANPP and discuss the pitfalls of scaling up from point data in landscape analysis.
The cover has a stunning color photo of Konza Prairie. I found few errors in the book. The figures are clear and well described. Most authors relate their results to broader research in their field. There is great material here which will lead the student and researcher into the extensive prairie literature (777 references are cited) and details about research methods. The story is not over though, and we can only wait for the results of new experiments to investigate fire seasonality, precipitation variability, resource heterogeneity, and grazing stocking rates on the tallgrass prairie system. This book is a successful synthesis of the research at Konza, linking population, community and ecosystem levels and showing the complexity of ecosystem dynamics. It is a fitting tribute to the great insight and accomplishments of long-term and integrated ecological research. Although the picture that emerges is complex, it is also predictable, which gives hope for understanding, preserving and restoring prairies. I highly recommend "Grassland Dynamics" because of its breadth and attention to ecological theory in a management context. I look forward to the other books in this series, if they are as well written.
- Noel B. Pavlovic, U.S. Geological Survey, Biological Resources Division, Lake Michigan Ecological Research Station, Porter, Indiana.
British Plant Communities. J.S. Rodwell (ed.). 1991-99.Volume 1. Woodlands and scrub (ISBN 0-521-23558-8 cloth [1991] US $160.00; ISBN 0-521-62721-4 paper [1998] US $54.95), 395 pp. Volume 2. Mires and heaths(ISBN 0-521-39165-2 cloth [1992] US $195.00; ISBN0-521-62720-6 paper [1998] US $54.95), 628 pp. Volume 3.Grasslands and montane communities (ISBN 0-521-39166-0 cloth[1992] US $195.00; ISBN 0-521-62719-2 paper [1998] US $54.95), 540 pp. Volume 4. Aquatic communities, swamps and tall-herb fens (ISBN 0-521-39168-7 cloth [1995] US $105.00; ISBN0-521-62718-4 paper [1998] US $54.95), 283 pp. Volume 5.Maritime communities and vegetation of open habitats(0-521-39167-9 cloth [1999] US ca. $160.00; ISBN 0-521-64476-3 paper [1999] US ca. $54.95),608 pp. Cambridge University Press, 40 West 20th Street, New York, NY 10011-4211.
The British have a long history of vegetation and plant community analysis that includes such influential works as those by A. G. Tansley. As a burgeoning European phytosociological movement inspired the development of systematic community classifications, a need to integrate descriptive analyses with a "rigorous taxonomy of vegetation types" became apparent. This series is the outcome of intensive floristic survey work began in 1975 when the British Nature Conservancy Council first contracted the project to assist with selection of habitats for conservation. The effort to provide "standardised descriptions of named and systematically arranged vegetation types" resulted in this monumental assemblage of five volumes dedicated to the characterization, classification and associations of more than 250 plant communities depicting woodland and scrub (25 types); mire and heath (60 types); grassland and montane (48 types); aquatic, swamp and tall herb fen (52 types) communities. The remaining maritime and open community types will be treated in the forthcoming fifth volume, which was yet unavailable for review but is scheduled to appear in July,1999.
The comprehensive coverage includes all of Great Britain except for Northern Ireland. The scope of the project does not simply focus on rare pristine communities, but strives to provide detailed accounts of all major communities ranging from sites with "long established vegetation" to "industrial and urban wasteland". Data for all communities are based on quadrat surveys and include abundance values derived from the Domin scale. Site localities were recorded on 1:50,000 series maps and much additional data (altitude, soil pH, water depths, bedrock, etc.) were compiled during the field surveys. Approximately 35,000 surveys were assembled from over 80% of the 100-km2 grids that cover the British mainland and major islands.
It is difficult to adequately convey the wealth of ecological information contained in these volumes. The results are presented in a format that prioritizes the definition of vegetation types that are arranged in categories of "communities", "sub-communities" and "variants". The use of code letters and numbers helps to identify each particular vegetation type. The codes are gratifyingly simple and easy to remember, e.g. "W" for woodland/scrub, "M" for mires, "H" for heath, etc. For each community, floristic tables (with frequency and abundance values) are used to summarize information collected during surveys. Accompanying text further describes the vegetational features with information on general physiognomy, habitat, constant and rare species, floristic and structural variation, interactions of climate and geology, and factors that influence community development and stability. To provide such detailed information for a single community would be no small task, but to assemble this compilation for several hundred communities across such as large region is truly a remarkable feat and represents an extraordinary accomplishment.
Volumes begin each section with an introduction that details the methods of sampling and helpful figures that summarize important features such as community relations to soils and climate. In volume 1, various figures illustrate diverse features such as phytosociological affinities of dry woodlands, the influence of major trees and shrub dominance to the community, and canopy and understory variation. Volume 2 includes figures describing fen, meadow, mire and heath zonation along with their variations. In volume 3 are illustrations describing convergence and loss of diversity in grasslands, the phytogeography of calciolus grasslands, vegetation sequences relating to soil variation, sequences of heaths with increasing snow-lie, and a late snow-bed vegetation complex. Included in volume 4 are diagrams of brackish ditch and upland lake zonation, vegetation patterns in abandoned canals, correlation of dominant and understory assemblages, an aquatic community mosaic, and a cross section of a fen and woodland community. These useful figures are not only informative, but help to break up the monotony of the serial community descriptions.
Keys to communities precede their individual descriptions. Realistically, they are provided as a "crude guide" but not as an "infallible short cut" to diagnosis. Keys (which emphasize frequency and abundance data) are primarily dichotomous and are designed to work best when used with constancy tables constructed from representative vegetation samples. Recommended quadrat sizes for different community samples are provided. No key is provided to aquatic communities (volume 4) which are characterized as species poor and are defined mainly by dominance of a few taxa. Instead, a "synoptic table" is incorporated to identify the aquatic communities using relative frequency data.
Other helpful features (in all four volumes) are the inclusion of indices to community synonyms and indices of species with codes of all communities in which they occurred. The latter is coded to reflect species that were constant in communities (bold) or sub-communities (italic). Each volume also includes a substantial bibliography of pertinent and up-to-date literature.
One criticism that I had was what I considered to be the unnecessary repetition of introductory material among the four volumes. The 13 pages covering "style of presentation" were repeated in their entirety in each of the four volumes. Likewise, the directions for each key were highly repetitive (occasionally within the same volume for different keys), but did include additional information for some vegetation types. This practice was particularly superfluous in volume 3 where essentially the same introductory comments were repeated for each of the three keys in that volume. It would have streamlined the work if the keys to all communities had been placed together in the first volume with only a single set of introductory comments. It would have sufficed to omit the "style of presentation" comments from all but the first volume. In total, these modifications alone would reduce the content of the series by nearly 55 pages. The bibliographies of each separate volume also contained a large number of repeated general references, e.g. works by Adam, Braun-Blanquet, Ratcliffe, Tansley, Tutin et al., etc. that were cited in all four volumes. Volume one could have included these citations in a separate category as general references and omitted them from the remaining volumes.
Although each volume had keys to the included communities, it would have helped to have a "master" key that directed the reader to the appropriate starting volume. As a North American, I would have sought the Alnus glutinosa-Carex paniculata (W5) community in volume 4 (Aquatic communities, swamps and tall-herb fens) because we consider any wetland dominated by woody vegetation to be a swamp. We have other regionally specific definitions for terms such as marsh and fen. However, this treatment employs quite a different usage of the term "swamp", which is a wetland "dominated by bulky emergent monocotyledons". Indeed, a number of the synonyms for the W5 community are referred to as swamps and clarification would have been facilitated by an introductory key, which would also serve to make this work of more universal appeal.
On the other hand, the consistency among volumes was excellent. The same basic format was followed rigorously for all the community treatments and indicated a meticulous editorial review of the work. Accordingly, all four volumes stand as cohesive treatments of an overall unified project rather than to appear as individual works with little continuity. In general, I liked the format. However, I might have preferred to have the distribution maps of communities placed together at the end of each treatment, rather than being scattered throughout the text.
The paperback copies that I reviewed were of good quality with sharp and even printing. The distribution maps were particularly crisp. The type is fairly small and lines are set somewhat close together, but the text is quite readable. Although this printing format reduced the overall size of the work, the extremely small margin used along the bound page edges would make them difficult to Xerox without some distortion. Only one of the four volumes was blemished by a series of folds in the corner of the first 50 or so pages. The bindings were glued well and the covers contained attractive color photographs. The subtitle print on the spine of volume 4 is reduced in size because of its fewer pages. Otherwise, all four volumes possess the appearance of a well-matched set. There are a few discrepancies in the publication information. Although volume 2 is said to be "first published in 1991" the publication date provided by Cambridge Press (http://www.cup.cam.ac.uk/) is actually 6 February, 1992. Volume 4 does not include the ISBN code or publication date for the paperback edition. That information (given above) was obtained from the Cambridge web site. These errors should be corrected in subsequent printings.
The fruit of nearly a quarter century of effort, this series on British plant communities represents an exceptional and comprehensive compilation that will become a classic and vital reference for ecologists and botanists. It is a pleasure to see the publication of such a careful and valuable contribution and one that also sets a new standard for field ecological surveys. The recent release of all volumes as reasonably priced paperback editions now makes this important reference work available to a wide audience of scientists and students.
- Donald H. Les, Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs
Metapopulation Biology: Ecology, Genetics and Evolution. Hanski, I. A. and M.E. Gilpin, eds. 1997. ISBN 0-12-323446-8 (paper US$44.95) ISBN 0-12-323445 (cloth US$89.95)512 pp. Academic press. 525 B Street, Suite 1900, San Diego, CA92101-4495.
The rapidly expanding interest in spatial dynamics of patches of animals and plants makes Hanski and Gilpin's edited volume Metapopulation Biology: Ecology, Genetics and Evolution a timely text for both population and conservation biologists. The editors tackle the great challenge of joining the fields of ecology, genetics and evolution under the rubric of metapopulation biology. In their first volume Metapopulation Dynamics: Empirical and Theoretical Investigations (Hanski and Gilpin, 1991) they used the narrow definition of metapopulation as a significant turnover of local populations, local extinctions and colonization . The second book explores the broader view of metapopulations as an assemblage of discrete local populations with migration among them through the varying perspectives of thirty authors.
The book contains four sections: conceptual foundations, metapopulation theory, metapopulation processes, and case studies. The opening section (Part I) develops several perspectives of the current state of the field. Wiens describes the need to link landscape ecology, a patterns based approach to describing spatial heterogeneity, to the more dynamic, process oriented nature of metapopulation biology. Part II explores the rapidly changing theories in metapopulation biology, extending from classical models to local community structure. Additionally, two chapters describe the role of population genetics in metapopulation theory. These chapters challenge research to move beyond descriptions of patterns of genetic differentiation among populations (as in the genetics case-study in Part IV) to extend our empirical understanding of what determines distribution of genotypes across a landscape.
Part III addresses more specific processes of extinction, migration, and establishment of new local populations. Ims and Yoccoz explore the limitations and advantages of several methods for obtaining empirical data on these three processes to support parameter estimates in theoretical models. The final section shows how the theoretical framework of metapopulation biology links into empirical data. The four examples include genetic and ecological data and use one example each of a mammal, a butterfly, a plant, and a plant-herbivore system. Only the butterfly example shows substantial evidence for the link between classical metapopulation theory and data, offering an open invitation for further tests of the models. The greatest discussion of plants is the final chapter on genetic structure. The authors (Giles and Goudet) begin by reminding us of population genetic theory and frame their discussion in a metapopulation framework.
The editors have made substantial attempt to link the distinct perspectives of ecology, evolution, and genetics through section introductions and frequent cross referencing among chapters, but many conceptual leaps remain to be tackled. Case studies, which were not present in the first book, still take a minor role in comparison to the theoretical portion of the book (four chapters of case studies as opposed to 11 chapters of theory). There is a bias through much of the book towards animal metapopulations. Moreover, there is a frequent bias towards a genetic perspective for plant studies, and a strongly ecological and ecological-theory bias in animal studies. I see the lack of plant examples as a challenge to botanists to examine how plants fit into the current theory, or how theory needs to be expanded in order to include specifics of plant systems in processes of local population extinction, migration and colonization.
The edited volume is an excellent updated introduction to the literature of metapopulation biology for all students of biology. I recommend this text to anyone with an interest in spatial patterning of organisms. However, some chapters are geared towards the modeling enthusiast, whereas other chapters walk the reader through the basics of certain fields, making it tough to tell if the intended reader is at the student or professional level. As the author's state, not all readers will equally appreciate each chapter. In general, the limitations of the book reflect the limitations in the application of the rapidly changing theory. This book shows that we are getting closer to the difficult link between ecology, evolution, and genetics under a metapopulation framework, but we are not there yet.
- Courtney J. Murren, Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269
Literature Cited
Gilpin, M. and Hanski, I. 1991 Metapopulation Dynamics: Empirical and Theoretical Investigations Academic Press, London.