Adaptation for future climate warming: the role of habitat creation in promoting species' range shifts.

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There is an emerging consensus that many animal species are responding to current climate warming by shifting their distributions northwards. However, in order to track climate, species must be able to disperse through landscapes that have been greatly altered by human activities, and where breeding habitats are often fragmented and scattered across inhospitable urban and agricultural landscapes. Because of this habitat loss, some species are failing to shift and are lagging behind climate changes because they are unable to reach new sites beyond the range margin. This failure to shift is of great concern because many species that are lagging behind climate are endangered species of high conservation concern. Even if greenhouse gas emissions were greatly reduced immediately, more warming would still occur because of inertia in the Earth's climate system. Thus there is a commitment to future warming regardless of any mitigation, and so adaptation measures are required urgently. One commonly suggested adaptation measure is the creation of new habitats as 'corridors' or 'stepping stones' to allow species to move through unsuitable landscapes, and to help them colonise new sites. However, this notion of habitat creation is essentially untested, and there is no comprehensive study of whether such adaptation methods might be successful, or how they might be implemented. The proposed work will provide the first systematic analysis of the importance of habitat availability on distribution lags in an entire group of insects (butterflies). We will develop new dynamic computer models that simulate range expansion through realistic British landscapes. The models take account of the availability of habitat and suitable climate, and also include biological processes such as dispersal, birth and death rates. We will (1) develop and validate dynamic models for all 46 resident, southerly-distributed British butterfly species. We will (2) use these models to quantify the degree to which habitat limits species' range expansion. We will (3) use models to examine the success of different habitat creation scenarios to examine which, if any, scenarios would be sufficient to allow range expansion, and which adaptation strategy is the best. The project will produce results of considerable practical value, as well as addressing fundamental questions about limits to species ranges. It will open up a new avenue of research on the impacts of climate change on biodiversity. Conservation strategies must include adaptation strategies, but conservationists are uncertain about what to do. The proposed work will provide a concrete body of scientific evidence to inform this debate.