New approaches to novel ecosystems
- Novel Ecosystems: Intervening in the New Ecological World Order, edited by Richard J. Hobbs, Eric S. Higgs, and Carol M. Hall. Wiley-Blackwell, 2013. US$79.95, €53.90, ￡45.00, hbk (368 pages), ISBN 978 1 118 35422 3
As the philosopher Thomas Kuhn pointed out, in science, there is normally one dominant worldview at a time. Inconsistencies accumulate, but are ignored until they become overwhelming, resulting in a rapid ‘paradigm shift’ to a new worldview. The shift that Novel Ecosystems marks is from the previous view of novelty in ecosystems as being exceptional and necessarily bad, to the no longer shocking idea that it is normal and, in itself, value neutral. The book grew out of a 2011 workshop that asked how managers should deal with these novel ecosystems. It has 20 main chapters, which explore the major issues, as well as several shorter case studies and perspectives. Most of the main chapters are good and surprisingly well integrated, thanks to file-sharing technology. The shorter chapters vary in quality, but are easily skipped or dipped into at random.
The editors avoid an ideological stance, making clear that they are not advocating the abandonment of all attempts to control non-native species. However, some of the authors are less circumspect and there is rather a lot about ‘embracing novelty’. The editors are also at pains not to be too prescriptive, so their ‘working definition’ of novel ecosystems does not appear until chapter 6: ‘A novel ecosystem is a system of abiotic, biotic and social components that, by virtue of human influence, differ from those that prevailed historically, having a tendency to self-organize and manifest novel qualities without intensive management.’ The key parts of this definition are novelty and human agency, plus, crucially, that novel ecosystems do not need continued human intervention to persist. Less successful is the attempt to define ‘hybrid ecosystems’, where the novelty is potentially reversible: it is a useful concept, but one that needs a better label.
Echoing previous controversies in ecology, there is a debate on whether there is a historical–hybrid–novel continuum or if clear thresholds separate these three types of ecosystem. I am sure that I will not be the only reader who finds this pointless: it is a continuum, guys, get over it. By contrast, other, potentially more interesting, issues get too little discussion. In particular, the significance of novelty in species composition is not given the attention that it deserves. Does it not matter that species have never interacted before? What about coevolution, enemy release, novel weapons, and evolutionary naivety? The vast invasive species literature says that these things do matter,so a novel ecosystem formed by a reassortment of species from the regional species pool is expected to differ in important ways from one formed as result of invasion by non-native species.
The management section of the book deals with some truly novel issues, given that, until recently, the only respectable management option for a novel ecosystem was to try to return it to its presumed historical state. There are parallels here with the way in which climate change adaptation has become not only a respectable, but also a fundamental part of conservation management, whereas it was previously seen as an admission of failure. In both cases, the goals of management still include the protection of native species and the maintenance of ecosystem services, but management actions now take into account the impossibility of restoring the past. However, as discussed in three useful chapters, novel management actions may run into problems with outdated values, inflexible laws and policies, and public opinion.
Who should read this book? Novel ecosystems are here to stay, by definition, and it is clear that we need to know a lot more about when and how to manage them. If you are in a hurry, the TREE review by Hobbs et al. covers many of the key points, but if you teach ecology, supervise graduate students, or manage protected areas, you probably need to read this book to get an idea of the emerging issues.