Several assessments have predicted that species restricted to extreme environments, such as mountaintops, the Arctic and Antarctic, would be most sensitive to small levels of warming. Indeed, these areas are showing the first signs of species declines and extinctions. New meta-analyses indicate large differences in magnitude of spring advancement between a major taxonomic groups, suggesting that normal interactions among species, such as flowers and the insects that pollinate them, may become disrupted. Evolutionary adaptations to warmer conditions have occurred at the local, population level, but observed genetic shifts are limited. There is no indication that novel traits are appearing that would allow species to exist under more extreme climatic conditions than they currently live in. As climate zones shift across the landscape, our current preserve network will no longer contain appropriate climates for the species for which those preserves were designed. Further, human domination of the landscape creates barriers to natural movements of species towards new geographic areas which have only recently become climatically suitable.
Results/Conclusions
There are now many examples of population extinctions due to climate change, with some species showing inability to disperse and colonize newly formed habitats outside their current range. Translocation outside of a species’ historic range is a new and untried concept. However, in situations where risk of extinction due to climate change is imminent, human-assisted translocation of individuals, often termed “assisted migration” or “assisted colonization”, may be necessary to ensure colonization of new geographic regions as parts, or all, of the historical species’ range becomes climatically unsuitable.
A second major tool used in conservation is restoration of degraded habitats. The guiding principles of ecological restoration rely heavily on historic condition both as reference points for assessing current status and as goalposts for recovery plans. Paradoxically, active management of natural ecosystems is essential to preservation of native biodiversity in regions where biodiversity has been shaped by prolonged human contact over many thousands of years. Climate change has expanded the geographic extent of human influences, and differs fundamentally from any other anthropogenic driver in that it cannot be reversed through local conservation actions. Creation of new habitats adapted to the climate to come, rather than climate of the past, should be considered as a second non-traditional method of helping wild species persist in a rapidly changing climate. Preservation of biodiversity in the face of climate change will require novel forms of management and unconventional measures of ‘success’.