This book, The Biology of Alpine Habitats, is the 14th in the series The Biology of Habitats (excluding four second editions), published by Oxford University Press with the goal of “providing an integrated overview of the design, physiology, and ecology of the biota, set in the context of the physical environment.” The series is aimed mainly at senior undergraduates and graduates taking courses in ecology or environmental science, as well as interested professionals. The authors, Laszlo Nagy and Georg Grabherr, both of the Department of Conservation Biology of the University of Vienna, are experts in vegetation science with much research experience in alpine environments.
The book highlights the uniqueness of alpine habitats with an example from South America: Along a longitudinal gradient of 30 kilometers there is a 0.2 degrees Celsius (°C) variation in air temperature, but along an elevational gradient of approximately 5000 meters there is a 29°C variation in air temperature. The book undertakes a comprehensive integration and synthesis of a variety of topics to provide an overview that recognizes the physical environment as the main template driving the biology in these areas. The authors' approach benefits from an in-depth focus on the functioning of alpine ecosystems and not just on community assemblage and adaptations. This attention to function is important for understanding the major variables driving these systems. The book is divided into 10 main chapters plus a chapter of concluding remarks.
The authors give excellent coverage of the variables (in particular landforms, hydrology, and soils) that create alpine habitats. There is a particularly good section on soil formation and soil types in relation to their worldwide spatial and temporal distribution, including the importance of cryoturbation in soil formation. Chapter 6 attempts to elucidate common themes and features of alpine ecosystems worldwide, highlighting the specializations of the communities and assemblages found in such ecosystems.
Chapter 8 examines the historical and contemporary biogeography, adaptations, and evolution of alpine organisms to explain the extent of their ranges and their relationship to climatic zones. It is evident that there is a relatively high abundance of endemic species in most alpine faunas—for example, there are 400 in the European Alps, and the Himalayas have the highest overall percentage at 50 percent. The authors express caution about applying island biogeography theory to alpine habitats, noting that the typical relationship between species diversity and area frequently does not hold there. This point is illustrated by the contemporarious alpine fauna of Scotland, where species richness has remained roughly constant since the last major ice age despite a significant reduction in land surface area. This maintenance of diversity is a result of the ability of alpine faunas to colonize and survive by evolving and adapting (some alpine plants can live for hundreds, even thousands, of years). The book's coverage of the adaptations and survival of alpine organisms is comprehensive and well integrated into the text.
The book also covers temporal and spatial dynamics in depth. The authors pay particular attention to primary succession in terrestrial vegetation on land exposed by retreating glaciers. There is a comprehensive section on the role of biotic interactions, including competition and facilitation, in comparison with the abiotic environment. The classic primary successional studies in Glacier Bay, Alaska, a nonalpine environment, are mentioned, although the authors might have helped readers more if they had compared this site with a typical alpine environment. The roles and impacts of herbivores on boreal alpine vegetation are considered in some detail in the discussion of different terrestrial habitats.
One of the most interesting sections of the book provides an overview of global changes in climate and in nitrogen deposition. It is clear that alpine environments are more sensitive to climate change than are many other areas. An examination of climate history clearly illustrates previous warming periods that drove to extinction species adapted specifically to living at altitude. As a consequence, only 22 of the 800 taxa recorded above tree line in the Pyrenees are not found below tree line. More taxa will be lost if warming occurs as expected. Alpine areas in Europe, apart from the Alps and the southern Scandes, would be virtually eliminated under the warming scenarios now expected. I only wish this discussion were longer.
The last section covers land use and conservation. Again, a fuller treatment would have been preferable, as these are key issues for alpine habitats. Nevertheless, there are comprehensive summary tables on alpine conservation problems and ecosystem values. In the concluding remarks the authors present a hypothetical ecosystem framework for alpine zone mountains that links their biodiversity and habitat diversity patterns principally to water availability.
Excellent summary tables throughout the book help to synthesize the material, and many of these have references to sources for further reading (although references are missing for a few key tables). Figures, most adapted or taken from other works, are also potentially helpful, but unfortunately many are difficult to read, particularly because of the shading. Some of the photographs seem to have been taken in color and then converted to black and white, which might explain their unfortunate lack of visual impact. An attractive feature is highlighted subject boxes that serve to focus the reader's interest on specific topics (e.g., phylogeography, cryptogams in succession on glacier forelands, proxy measurements for climate). There is an extensive list of more than 800 references, but fewer than 35 of these date from later than 2006.
The book would have been more appropriately titled “The Biology of Alpine Terrestrial Habitats.” As a freshwater ecologist I was disappointed that coverage of freshwater habitats, including glacier-fed streams and alpine lakes, was virtually absent, apart from a brief description of “life in troubled waters” (about glacial rivers, though it sounds like a Simon and Garfunkel song) and a brief mention of the effects of ultraviolet-B radiation on crustaceans in alpine lakes. The authors state that “the biology of alpine freshwaters is discussed in detail in specialist texts,” but they provide no references, and thus lose the opportunity to fully examine the linkages between terrestrial and freshwater ecosystems in alpine habitats. This is unfortunate, because streams have important influences on soil moisture as well as on carbon and nitrogen fluxes.
That said, the book definitely fulfills its goal with regard to terrestrial alpine habitats. Its strength lies in how it synthesizes the major driving variables, which include elevation gradients, energy and climate, landforms, and hydrology and soils, while also examining the responses of community types and assemblages, including their biogeography, adaptation, and evolution. The paperback will appeal to students interested in or taking courses involving alpine habitats as well as to professionals looking for an introduction to this environment.
