Review: Conservation biology has developed rapidly over the last 10-15 years. From being a small branch of applied ecology it has developed in its own right and now offers a unique perspective on the way in which we deal with the biosphere. Here we have a text which has followed much of this development with a third edition (here with a co-author) in less than 12 years. The two central questions are therefore the nature of the content (for those new to the text) and the quality of the upgrades (for those with earlier editions). There is also the issue of scope for although this is titled as a biology text its coverage is applied and angled at biodiversity.

In terms of content, the book is divided into four sections. The first of these deals with the nature and significance of biodiversity. We start with an overview of conservation biology and how it has developed. This moves on to consider the concept of biodiversity (or rather concepts as this term has more than one definition). Subsequent chapters deal in turn with each of these concepts investigating the parameters and limitations. Part two focusses on threats to biodiversity. These threats are both natural and human-induced and this section looks at all key elements. Chapter six looks at diversity through time and the main mass extinctions. It blends current concerns with past events and demonstrates the links between the two. This is just pattern. Chapter seven looks at the processes behind these patterns and how they may be analysed. The focus now turns to human influence with three chapters linked by human involvement. Chapter 8 starts with an exploration of ecosystem-level changes and degradation of areas. This is followed by two chapters examining species alteration firstly by removal (unsustainable exploitation) and addition (invasive species) to the environment. Part three moves on to the protection of biodiversity. Chapter 11 starts this part by outlining the main ways to find and protect areas from site design to management and protection. Chapter 12, managing ecosystems, starts with the difference between conservation and preservation and then at the more practical side of keeping (and/or restoring) an area either wildscape or a more modified system. This moves on to conservation of species and manipulation of populations whilst the final chapter looks at the more controversial issue of ex-situ conservation through zoos and gardens. Part four looks at the reasons we need parts one to three - human involvement. As much as we would like it, conservation does not take place in a sterile vacuum but in a kaleidoscope of inter-related human actions - the social, economic and political milieu and mores that define each nation or civilisation. There's a sense here that the volume of material couldn't fit into these chapters but we do get an overview of the range of possibilities. The text does finish on a positive note suggesting that international action is both possible and desirable.

This third edition still retains considerable portions of earlier texts but there has been some significant upgrading. Most noticeable is the presentation which now makes the book very inviting - a key issue for introductory readers. There are a few renamed chapters and new areas such as invasive species but these add to the use of the book. Overall, this book retains the quality of information of previous versions and adds better production which makes it a very useful addition to the library.