The Challenges of Biodiversity Science (review)

This is a very unusual book on biodiversity. Generally speaking, biodiversity books either cover the central ecological question of how the vast variety of life comes about or what effects biodiversity loss in an era of major global change may have. This book integrates both aspects of biodiversity and then goes even further, expanding into the social, political, societal and spiritual aspects and challenges of biodiversity normally barely touched on by academic ecologists. This book is a part of an Excellence in Ecology series, which involves books written by International Ecology Institute (ECI) laureates who have contributed significantly to advancing the field of ecology. These books summarize key advances in the field and are very pertinent to ecology-related decision making and policy. In his book, Michel Loreau covers a wide span of ground related to the important topic of the diversity of life on earth and reaches out to a wide audience. This integrative approach to the current challenges of biodiversity science is a welcome and necessary step towards a better and more open communication and networking between stakeholders, particularly in the current International Year of Biodiversity. Until recently, biodiversity science and policy have developed along quite separate trajectories, and the current book makes a clear call for the stronger emphasis on policy by the international Convention on Biodiversity (CBD) to be backed up by a stronger framework of science. At the same time, Loreau argues for a reexamination of our cultural values related to how we perceive and how we relate to nature. As such, this book will be of inherent use and interest to people dealing with biodiversity from across the spectrum of science to management and policy.

One can split the book into two main sections—the first section deals with developments in biodiversity science, followed by the currency of biodiversity (what is it and how does one measure it, and where are the limits to our measurements?), and then moves on to key aspects of current biodiversity loss and extinction. Loreau highlights in Chapter 1: The Emergence of Biodiversity Science that the coining of the term “biodiversity” at the end of the 1980s helped to unify different concepts of biodiversity that were previously researched quite independently of one another. Nevertheless, despite an initiative to improve the networking of biodiversity science using the DIVERSITAS network (after the CBD was founded at the 1992 Rio Conference on Environment and Development), taxonomists, ecologists, conservationists and environmental economists continued to work on questions very much delimited by their research fields. Ironically, as Loreau writes, “scientific diversity mirrored biological diversity” (p.7), until after 2001 when DIVERSITAS managed to reorganize itself and have a major impact on integrating biodiversity science and linking science and policy. Loreau makes a strong case for the need for unity in diversity, despite the fact that integration across disciplines is particularly challenging in the field of biodiversity compared to major environmental issues, such as stratospheric ozone depletion (with its relatively simple chemical cause and effect) or climate change (with its environmental complexity, but which revolves around the core discipline of climatology and the core tool of general circulation models). In Chapter 2: What is Biodiversity, he presents the question of how to measure the diversity of organisms, covering concepts of species numbers, species evenness, species-area curves, and diversity indices, and more recent trends of studying the dissimilarity of diversity between sites or qualitative differences in diversity, such as phenotypic or trait diversity, instead of just focusing on the number of species. Drawing on some of his earlier work, Loreau describes how species-area relationships have so far been one of the only ways for ecologists to predict the effects of habitat fragmentation and destruction on biodiversity, but how these measures are nonetheless extremely scale-dependent. As such, he proposes a general unification of measures of diversity, using Renyi’s measure of entropy and Hill’s diversity index and additive partitioning methods, whereby it is possible to separate...