Plant species' response to climate change: implications for the conservation of European birds

Wildlife conservation faces new and extreme challenges in adapting to the accelerating dynamics of a world responding to global change. The Quaternary record shows that migration has been the usual response of organisms to environmental change. This record also reveals that forecast future climate changes are of a magnitude and in a direction unprecedented in recent earth history: the rate of these changes is likely also to surpass that of any comparable change during the last 2.4 million years. The relationship between a species' geographical distribution and present climate may be modelled by a surface representing the probability of encountering that species under given combinations of climate conditions. This ‘climate response surface’ then may be used to simulate potential future distributions of the species in response to forecast climate scenarios. Such simulations reveal the magnitude of the impacts of these forecast climate changes. Although to date this approach has been applied in Europe only to plants, it promises to be valuable also for other groups of organisms, including birds. Some bird species, however, may respond more directly to either habitat structure or presence of specific food plants; such factors may be incorporated into the models when required. The magnitude of likely vegetation changes necessitates a global approach to conservation if there is to be any hope of long-term success. Successful conservation of global biodiversity will depend upon conservation of the global environment and limitation of the human population much more than upon parochial efforts to conserve locally rare organisms or habitats.