Integrating multiple modelling approaches to predict the potential impacts of climate change on species' distributions in contrasting regions: comparison and implications for policy

Many studies have predicted the potential impacts of climate change on species' distributions at large spatial scales, yet the role of more local-scale effects remains poorly explored. Addressing more localised impacts requires that new integrated modelling approaches are developed to address fine-scale processes including species' dispersal and local connectivity. Here we integrate four models (a continental scale bioclimatic envelope model, a regional scale bioclimate and land use suitability model, a dispersal model, and a connectivity model) in a scale-dependent hierarchical framework. The approach has been used to analyse the fine scale impacts of climate change on species' distributions within two contrasting case study regions located in East Anglia (UK) and Almeria (Spain). Eight and six species respectively were used to test our approach under three climate change scenarios. Despite the uncertainties inherent in the modelling approach, our analyses suggest two general conclusions: (i) climate change involves the development of transient conditions and fragmentation within the core of species distributions; (ii) climate change would favour the opening of gaps within the current vegetation zones, rather than a simple zonal shift of them. Dynamic and integrated conservation policies are required, that take account of the current and potential future spatial arrangement of species and their habitats, to assist species to respond to future environmental change. (c) 2005 Elsevier Ltd. All rights reserved.