Space: the final frontier

Abstract

book reviews ISSN 1948-6596 Space: the final frontier Spatial Simulation: Exploring Pattern and Process. David O’Sullivan & George L. W. Perry, 2013, Wiley–Blackwell. 305 pp. £85.00 (hardback) / £39.95 (paprback) ISBN: 9781119970804 / 9781119970798; http://eu.wiley.com In 1994, a special feature in Ecology highlighted the prominent role of space in ecological theory and emphasized that for many ecologists, spatial complications were used as a catch-all for explain- ing away surprising results (Kareiva 1994). And indeed, Volker Grimm reiterates in the foreword of ‘Spatial Simulation’ by O’Sullivan & Perry that there is still ‘no general theory’ of how space mat- ters. However, while Kareiva complained that there were no serious experiments testing spatial theory, O’Sullivan and Perry complain 20 years later that there is no general theory. Conse- quently, their book is about simulation (something which might be considered to be between theory and experiments) of spatial patterns and proc- esses with an emphasis on three broad categories: aggregation and segregation, random walk and mobile entities, and growth and percolation. For each of these categories the book provides sys- tematic and comprehensive overviews of simple, generic models that can be used as building blocks for more complex and specific models. Through- out the book, well-developed examples are dis- cussed and implemented in the free software Net- Logo (Wilensky 1999). A companion webpage pro- vides the reader with a model zoo, i.e. all simula- tion models chapter-by-chapter, ready to be in- vestigated and explored by the interested reader, potential user and developer. Covering examples across a wide range of disciplines that comprise the contemporary social and environmental sciences from archaeology to urban geography, O’Sullivan and Perry’s general introductory chapters are very helpful in order to understand the various concepts, definitions and tools necessary to simulate complex spatiotempo- ral patterns and processes. I particularly liked their emphasis on the heuristic value of constructing spatial simulation models. Rather than emphasiz- ing predictions, which may never be possible be- cause of non-linearities and stochasticity leading to deterministic chaos, spatial simulation models play a great role in exploring complex aspects and increasing our understanding of spatial patterns and processes. My own background is in plant ecology and an armada of conceptual, analytical and virtual spatial simulation models have been proposed for example to model the dynamics of forest communities or to explain species coexis- tence at spatial scales from local to global. What we are still lacking is a systematic overview of core ideas and concepts. O’Sullivan and Perry’s first two chapters really help to tame ‘the bewildering array of ideas’ (Chesson 2000) in the context of spatial simulation models. The book may even contribute substantially to promoting consistent terminology and to ordering or organizing key concepts of spatial simulation models more for- mally. After covering the basic building-block mod- els (e.g. interacting particle systems, random walks, percolation and growth) quite comprehen- sively in chapters 3–5, the remaining chapters cover the various possibilities for representing space and time and put things into perspective by considering model uncertainty and evaluation (one of the best and most useful chapters). The two final chapters weave things together using the example of island resource exploitation by hunter-gatherers and provide an overall conclud- ing chapter summarizing the main conceptual ideas and themes (i.e. utility of building-block ap- proach, challenge of inferring process from pat- tern, need for careful evaluation of spatial simula- tion models). Overall, this book and its associated web- page provide a very thorough and comprehensive starting point for students and researchers from various fields who might seriously consider adding a spatial component to their empirical or model- ling work in order to answer their specific ques- tions. There were, however, two points which I did not like very much. First, the authors promise to cover important points in some places, but frontiers of biogeography 6.2, 2014 — © 2014 the authors; journal compilation © 2014 The International Biogeography Society