Abstract
Richard Bradshaw and Martin Sykes, the authors of Ecosystem Dynamics: From the Past to the Future, will be well known to most readers of this journal for their original contributions to Holocene research over the past 20–30 years. Their work, individually and together, has focused on long-term vegetation dynamics and landscape changes which provide the theme of this book. In particular, they aim to develop and explain the linkages between knowledge and experience from the past (data) and how these can be used to inform the management of Earth’s terrestrial systems in the future (models). Their lofty ambition is that this book will help prepare the ground for writing the owner’s manual for a new generation of Earth’s managers. To this end, the intended audience is graduate students and graduate courses or seminars that cover ecosystem dynamics. However, they also hope that it will have a broader appeal and be accessible to the interested non-academic reader.
Four key questions are central to the book. How have ecosystems changed in the past? How much of this change is attributable to human activities? How much change is anticipated for the future? What are the appropriate ecosystem management measures by which to prepare for the future? In addressing these, the authors emphasise the role of modelling ecosystem dynamics. Thus, Chapter 2 provides a detailed introduction to modelling. The range of models considered is wide, including equilibrium and dynamic models, biomes and ecosystems, trait-based and species-level models, Earth-System models and Agent-based modelling. For the non-academic reader, this is, perhaps, the most challenging chapter given the inevitable inclusion of acronym-based model names such as STASH, PHENOFIT, BIOMOD, DOLY, MAPPS, JABOWA and TRIFFID. Chapter 3 provides an overview of different types of data used for reconstructing environmental change and validating models; the focus is mostly Holocene. Both Chapters 2 and 3 start with an initial historical perspective on respective developments in their fields taking us back to the 4th century
Chapters 4 and 5 focus on past relationships between environmental change and ecosystem dynamics. The former considers climate changes from very long–term records, such as Tenaghi Philippon, to modelling Holocene vegetation dynamics and the difficulties of teasing out the role of climate (as opposed to human activity) as a driver of vegetation change. Emphasis in the latter is given to Fennoscandia, given its role as a ‘powerhouse’ of pollen research and, of course, the wealth of the authors’ knowledge from this region. In Chapter 5, the focus is on episodic events as drivers of ecosystem dynamics. There is a deliberate avoidance of the word ‘disturbance’ which implies a temporary disruption to a stable state or orderly succession; instead, episodic events are recognised as integral to ecosystems and their dynamics. This is illustrated by reference to several different forest studies (Sweden, North America, New Zealand, Australia). Focus then shifts to phenomena such as fires, pathogens, hurricanes and wind damage and how models can be used to understand their impacts on ecosystems, for example, in modelling the spread of fire based on availability of fuel and on various climate parameters, such as wind, temperature and humidity.
Chapter 6 provides regional case studies illustrating the impact of past and modelled future human exploitation on terrestrial ecosystem dynamics. Examples derive from Denmark (Holocene), islands (sensitivity to impact), forests in the Mediterranean, temperate and boreal zones and from the Tropics. There is also a concluding section on spatial up-scaling and ecosystem consequences of human impact.
As a rationale for writing this book, the authors use the analogy of humans occupying the driving seat in all terrestrial ecosystems and refer to the warning lights flashing on the dashboard and the touch-screen controls that alter land-use, greenhouse gas emissions, hydrology, soil properties and genetic diversity. These are central elements in Chapters 7, 8 and 9 with their analyses of the provision of ecosystem services, the importance of cultural ecosystem services and how modelling past and present ecosystem dynamics can be used to inform modern conservation. These chapters are particularly accessible to the non-specialist reader as they reach into policy issues and the trade-offs needed between science and policy and economics and policy. The final chapter is titled ‘Where are we heading’ and reflects back on the four questions central to the book.
Does this book meet its intended expectations? In the introductory chapter, the authors state that this book ‘is not light reading’ but that they ‘have tried to make it accessible to the interested non-academic reader’. In general, they have been successful and I would recommend this book for our final year geography undergraduates, as well as beginning Masters students. Inevitably, a single volume cannot cover all areas in equal depth, but it provides a useful introduction to modelling ecosystem dynamics. Each chapter includes a summary at the end of sections and suggested further readings. There are also 25 pages of references (although relatively few post-date 2010) and 13 pages of glossary. Visually, the book is well laid out. However, the reproduction quality of diagrams is not consistently good. This applies especially to maps in Chapter 2, which are sourced from other publications, and which are printed at a poor resolution such that the legends are difficult to discern. Unfortunately, I also consistently failed when trying to access the Companion Website (http://www.wiley.com/go/bradshaw/sykes/ecosystem) which supposedly provides powerpoints of all the figures and PDFs of tables from the books. Instead, I found myself at a general Wiley page on resources and events, but with no easy-to-click links to the material for which I was searching. This is not, clearly, the fault of the authors, and will hopefully be remedied by the publishers.