Can multiscale models of species’ distribution be generalized from region to region? A case study of the koala
Article first published online: 26 NOV 2007
© 2007 The Authors. Journal compilation © 2007 British Ecological Society
Journal of Applied Ecology
Volume 45, Issue 2, pages 558–567, April 2008
How to Cite
McAlpine, C. A., Rhodes, J. R., Bowen, M. E., Lunney, D., Callaghan, J. G., Mitchell, D. L. and Possingham, H. P. (2008), Can multiscale models of species’ distribution be generalized from region to region? A case study of the koala. Journal of Applied Ecology, 45: 558–567. doi: 10.1111/j.1365-2664.2007.01431.x
- Issue published online: 26 NOV 2007
- Article first published online: 26 NOV 2007
- Received 13 December 2006; accepted 14 September 2007Handling Editor: Fangliang He
- cross-regional prediction;
- forest fragmentation;
- habitat loss;
- geographical range;
- landscape context;
- mixed-effect model;
- wildlife conservation over large area
- 1While various studies have evaluated the habitat requirements for wildlife in fragmented forest landscapes at multiple spatial scales, few have considered whether there is regional variation in the most important factors. This is a conundrum for managers of any species with a broad geographical range: to what extent should studies in one region inform decisions in another?
- 2We addressed this question using a case study of the koala, Phascolarctos cinereus, in three biogeographically different fragmented forested landscapes in eastern Australia. Mixed-effect logistic models were applied to predict koala occurrence from explanatory variables captured at four spatial scales: the individual tree, the stand (<1 ha), the patch (1–100 ha) and the landscape (100–1000 ha).
- 3We used model averaging to account for model and parameter uncertainty, and tested the cross-regional discrimination ability of the models.
- 4We discovered that multiscale models of koala distribution cannot be readily generalized from region to region, and that specific conservation actions for each region, rather than the entire geographical range, are more appropriate. We found a strong justification for adopting a hierarchical landscape approach to koala conservation across its range. However, cross-regional differences in habitat relationships occurred within this hierarchy. Exceptions were landscape context, which showed a consistently strong effect and high rank in all regions, and the presence of individual preferred tree species of the genus Eucalyptus, which showed modest consistency in its interaction with large-diameter trees across the regions. In contrast, the remaining habitat variables, including patch size (a key management factor), showed moderate to strong cross-regional variation attributed to the interaction of edaphic factors, landscape history and contemporary land-use patterns.
- 5Synthesis and applications. Adopting a uniform conservation programme over a large geographical area is attractive to policy-makers and conservation planners. However, our study confirms the lack of generality of species distribution models over large areas. Consequently, we argue against adopting a uniform conservation programme for species with a large geographical range.