Ecosystems of the World 16: Ecosystems of Disturbed Ground

L. R. Walker (ed. ) (1999). Pp. xii + 868. Elsevier, Amsterdam, The Netherlands. ISBN 0-444-82420-0. Price 246. 50 (hardback). Here is number 16 in the acclaimed Ecosystems of the World series. Unlike the others, its title does not immediately convey a geographical region nor correspond with any particular biome. The uninitiated could be forgiven for thinking that the volume would deal mainly with human impacts on the biosphere. However, natural disturbances can be found in all ecosystems. The task for the editor was to refine the choice of topics and present a balanced and consistent text. The scope of the volume is explained in the Preface and Chapter 1. Contributions then deal primarily with natural disturbances (Chapter 2–13), so-called anthropogenic (sic), i. e. human-induced, disturbances (Chapter 14–20), overviews of natural processes that occur across disturbance types (Chapter 21–27), and ‘human interactions with and responses to disturbance’ (Chapter 28–30). Concluding chapters deal with ‘Economic growth, human disturbance to ecological systems and sustainability’ (Chapter 32) and ‘Disturbance in terrestrial ecosystems: salient themes, synthesis and future directions’ (Chapter 33). The volume contains a short glossary of technical terms. It also has a systematic list of genera, although quite why this is here is unclear: it is impossible to use quickly, unless the reader knows where in the hierarchy a taxon should appear – in which case, why bother! More usefully, there is a comprehensive Index to the volume. References are listed after each chapter, but the assiduousness of referencing varies: one chapter (Chapter 3) has 30 pages of references, which is some six times the norm. The authorship is principally American: 46 of the 65 contributors hail from the USA, one is from Canada and six from the Argentine; these 53 New World ecologists contrast with nine contributors from Europe, one from (Asian) Russia, and two from the Antipodes. Although the text was published in Europe, the spelling is North American. The intention was to be global in coverage, as the editor recognized that disturbed ecosystems occur on all continents, including Antarctica. There is an eclectic mix of topics: some are generic, others biome-specific. All concern the terrestrial realm; the volume does not attempt to address atmospheric or aquatic disturbances, but some aquatic (e. g. flood) or atmospheric (wind) disturbances that directly affect terrestrial ecosystems are covered. In Chapter 2, John Matthews presents a summary of disturbance regimes and ecosystem response in recently deglaciated terrain, informed by his research in Norway. The following chapter, which primarily considers natural stress and disturbance in cold region ecosystems, contains a section on human disturbances. This includes assertions that others might challenge: for example, “Humans … hunted many animals to extinction during the Ice Ages”, and in the Russian Arctic, reindeer accounted for 49. 7% and polar bear for 43. 8% of the prey of hunters at 7800 BP (p. 58), which implies a remarkably precise knowledge of prehistory! By way of compensation, it is this chapter that has the most extensive bibliography. Chapter 4 deals with the ecological effects of erosion. It appears in the section identified as that primarily concerned with natural disturbance. However, human activity is often paramount in creating the conditions for accelerated soil erosion to occur, and the effects of soil erosion in agricultural lands frequently require a human response; so, this chapter could equally have been placed in the later section of the volume on “human interactions with and responses to disturbance”. More obviously ‘natural’ are the volcanic disturbances and ecosystem recovery described in Chapter 5. Succeeding chapters take the reader on a latitudinal sojourn, from Boreal forest (Chapter 6) to a consideration of wind disturbance in forests of the temperate-zone (Chapter 7) and tropics (Chapter 8). Forest features again in Chapter 9, but here the herbivorous activities of insects are the focus. Chapter 10 is concerned with disturbance in Mediterranean-climate shrublands and woodlands. The natural (sic) section includes a chapter on grazing, fire and climate effects on primary productivity of grasslands and savannas (Chapter 11), although some of the identified climatic effects sound more like ‘stress’ than ‘disturbance’ factors (sensu Grime 1979). Similar caveats apply to the chapter on disturbance in deserts (Chapter 12). The last of this section (Chapter 13) focuses on disturbance regimes in North American wetlands. In the next section, some Chapters deal with particular aspects of human activity: for example, Chapter 14 is called simply ‘Mining’, whereas Chapter 15 is concerned with disturbance occasioned by military training exercises. Chapter 16 focuses on disturbance in urban ecosystems, whilst Chapter 17 is a fascinating account of disturbance and biological invasions. Aspects of human disturbance in temperate forests of the north hemisphere (Chapter 18), tropical forestry (Chapter 19) and the pampa (Chapter 20) follow. Chapters 20–27, which concern themselves with the relationship between disturbance and particular ecosystem properties (physical aspects of soils, soil microorganisms, C and N cycling, primary production, primary succession, secondary succession, animals), seem somewhat out of place and might have been set earlier in the volume, in the ‘natural’ section. More appropriately, the concluding chapters (Chapter 32–33) help to round off the volume. This book is unlike others in the Ecosystems of the World series. The rationale is inherently suspect: if this, then why not a companion volume on ecosystems of undisturbed ground? (Indeed, is there any ground that is not disturbed in some way? Perhaps examples are some pristine peatlands? ) As the editor admits, “The development of theory related to disturbance is in its infancy” (p. v). Nevertheless, if one accepts the rationale, then this volume is a major compendium on the subject. There is much here to inform teaching and learning, and numerous avenues of research to be explored further. It is a particularly valuable source-book on the subject of disturbance in ecosystems, and it contains some stimulating contributions. The price will deter many, but the volume might usefully be bought for the institutional library.