Present address: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR7 4TJ, UK.
An objective, niche-based approach to indicator species selection
Article first published online: 19 JAN 2012
© 2012 The Authors. Methods in Ecology and Evolution © 2012 British Ecological Society
Methods in Ecology and Evolution
Volume 3, Issue 2, pages 317–326, April 2012
How to Cite
Butler, S. J., Freckleton, R. P., Renwick, A. R. and Norris, K. (2012), An objective, niche-based approach to indicator species selection. Methods in Ecology and Evolution, 3: 317–326. doi: 10.1111/j.2041-210X.2011.00173.x
Correspondence site: http://www.respond2articles.com/MEE/
- Issue published online: 4 APR 2012
- Article first published online: 19 JAN 2012
- Received 15 June 2010; accepted 11 November 2011 Handling Editor: Daniel Faith
- composite indicator;
- farmland birds;
- niche space;
- resource availability
1. Species-based indices are frequently employed as surrogates for wider biodiversity health and measures of environmental condition. Species selection is crucial in determining an indicator’s metric value and hence the validity of the interpretation of ecosystem condition and function it provides, yet an objective process to identify appropriate indicator species is frequently lacking.
2. An effective indicator needs to (i) be representative, reflecting the status of wider biodiversity; (ii) be reactive, acting as early-warning systems for detrimental changes in environmental conditions; (iii) respond to change in a predictable way. We present an objective, niche-based approach for species’ selection, founded on a coarse categorisation of species’ niche space and key resource requirements, which ensures the resultant indicator has these key attributes.
3. We use UK farmland birds as a case study to demonstrate this approach, identifying an optimal indicator set containing 12 species. In contrast to the 19 species included in the farmland bird index (FBI), a key UK biodiversity indicator that contributes to one of the UK Government’s headline indicators of sustainability, the niche space occupied by these species fully encompasses that occupied by the wider community of 62 species.
4. We demonstrate that the response of these 12 species to land-use change is a strong correlate to that of the wider farmland bird community. Furthermore, the temporal dynamics of the index based on their population trends closely matches the population dynamics of the wider community. However, in both analyses, the magnitude of the change in our indicator was significantly greater, allowing this indicator to act as an early-warning system.
5. Ecological indicators are embedded in environmental management, sustainable development and biodiversity conservation policy and practice where they act as metrics against which progress towards national, regional and global targets can be measured. Adopting this niche-based approach for objective selection of indicator species will facilitate the development of sensitive and representative indices for a range of taxonomic groups, habitats and spatial scales.