Diversity in Three Tenses
Version of Record online: 21 SEP 2006
Volume 20, Issue 5, pages 1560–1561, October 2006
How to Cite
Roberts, J. (2006), Diversity in Three Tenses. Conservation Biology, 20: 1560–1561. doi: 10.1111/j.1523-1739.2006.00549_3.x
- Issue online: 21 SEP 2006
- Version of Record online: 21 SEP 2006
Tropical Rainforests. Past, Present, and Future. Bermingham, E., C.Dick, and C.Moritz , editors . 2005 . The University of California Press , Chicago , IL . 672 pp . $45.00 (paperback) . ISBN 0-226-04468-8 .
Tropical Rainforests. Past, Present, and Future does not contribute directly to the fund of knowledge about the functioning of tropical rainforests nor is the book a compendium of descriptions of rainforests differing in structure and composition. Largely this book is about the rich diversity of species in tropical rainforests and particularly the mechanisms that might be responsible for such diversity. In tropical rainforests sound knowledge of how diversity might originate and be maintained is needed as a basis for interventions to conserve or even reinstate tropical rainforest.
This book is primarily the result of a scientific meeting on rainforests held in 1999. Some additional papers were commissioned later. Chapters in the book are organized into three parts. The first part, “Evolutionary and Ecological Determinants of Tropical Rainforest Diversity,” examines the likely mechanisms of rainforest diversity in 14 chapters (about half of the book). Part II is a showcase for the tropical rainforest in the north Queensland region of Australia (“A Multidisciplinary Perspective on an Entire Rainforest System: the Australian Wet Tropics”). Part III has four papers that take a forward-looking perspective on the rainforest (“Rainforest Futures”). Each part has an overview chapter by the editors that usefully sets the following chapters of the section into context.
The first chapters in the Part I, by Riklefs and Hubbell, are scholarly presentations of different views of how diversity in tropical forest regions might arise. Expectedly, there are equally strong arguments for diversity arising by an overlaying of ecological interactions on a historical legacy of species composition and for the chance occurrence of diversity. These papers are important scene setters and are followed by a dozen papers that each offer important messages about diversity and its origins. A chapter by Flenley shows that the pollen record can be used to show an increase in diversity with decline in latitude, and it provides a good resource for examining whether diversity fluctuates with climate. In the next chapter Colinvaux argues that the Amazonian rainforest was a stable formation in the face of previous climate change and did not recede into refugia as some earlier authors have suggested. Patton and da Silva examine the phytogeographic problems exhibited by Amazonian mammals and argue for a long history of the species that predates the Pleistocene. Smith et al. look at ecotonal speciation, particularly at forest–savanna boundaries, and suggest that ecotonal populations are phenotypically quite different from relatives in the main forest.
The book as a whole is relevant to conservation biologists, although some chapters offer particularly important messages. The chapter by Feldså et al. suggests that as more is learned about the geographic and temporal origins of species, how to protect biodiversity and the processes that produced it may be determined. The authors show a link between the level of diversity in tropical lowlands and that in nearby tropical montane zones. This is yet another reinforcement of the case for the conservation of tropical montane habitats. Brown's chapter presents a formidable analysis of butterfly communities in 48 Neotropical sites from Mexico to southern Brazil. It shows that a large proportion of species endemism coincides with paleological refuges formulated on the basis of geologic and climatic data. Brown concludes his chapter with a readable section that offers recommendations for the choice and management of forest landscapes to conserve the butterfly fauna.
An interesting approach to the examination of species diversity in tropical landscapes is presented by Mackey and Su, who use computer models to predict the spatial scales over which stimuli such as disturbance are likely to occur. Such approaches are at a very early stage, but hint at an enormous potential in the future. An important message that comes from the paper by Ruokolainen et al. is that in some geographical regions, the knowledge of plant taxonomy, ecology, and biogeography is not yet developed enough to answer questions about the spatial scale of species turnover. Leigh and Rubinoff provide an account of ecological interaction and mechanisms that regulate populations in complex rainforests. These authors rightly point to the importance of allies and enemies (mutualists and pests) of species that might underlie the structure of rainforest and reefs. Another salient message for conservation comes from the paper by Condit and his colleagues. They show marked variation of species numbers between plots regarded as similar in terms of rainfall and soils, which indicates that conservation planning perhaps should not be based on habitat selection alone.
It is not unexpected in this book that recent climate change, stemming from human activities involving CO2 increases and deforestation, receives attention. These changes are thought to produce reduced precipitation, higher temperatures, and a more pronounced seasonality. The chapter by Wright looks at El Niño events as an indicator of likely consequences of a future changing climate. There is a prospect that even the most robustly conserved tropical rainforests will not be exempt from the impacts of climate change.
Unlike some of other, much larger, tropical rainforest regions, the rainforest in Northern Australia is relatively small in area, has significant protection status, and is well researched. The region then offers a good example of what can be achieved by focussed effort. The second part of the book comprises some of the research emerging from the Australian tropical rainforest. After the overview there are four papers that set the scene in terms of the historical events that have lead to the diversity in this particular rainforest. These papers are followed by three that examine specific aspects of diversity in arthropods, freshwater invertebrates, and the significance of tree seedling performance on forest diversity. The final chapter in this part is by Nigel Stork, who elegantly argues for a strong link between research and management. The final part (III) of the book is “Rainforest Futures.” A particularly useful chapter in this section further examines the relationship of evolutionary knowledge to rainforest conservation. The final two chapters examine the challenges of the conflicting demands of the development and conservation in Southeast Asia and the Amazon. These chapters make sobering reading for anyone concerned about the future of rainforests. Nevertheless, they may, as with the book as a whole, stimulate young and established scientists to engage in diversity research in rainforests assured that their findings ultimately might well be linked to conservation strategies.
The book is largely free from errors throughout and has an impressive collection of literature citations (references for all the chapters are brought together at the end). At US$45.00, the book provides excellent value for those wishing to read some or all of a worthwhile collection of papers about tropical rainforest diversity and attempts to offer explanations of its causes and how research might support conservation.