Cold climate plants in a warmer world

The present cold adapted floras of arctic and alpine regions are frequently considered as being at risk from climatic warming. However, the prospect of higher temperatures liberating large areas of land from permanent ice cover in the Arctic plus a retreat of the nival zone on higher mountains could provide new terrain for the continued existence and expansion of both arctic and alpine floras. Examination in detail of these floras reveals numerous examples of species that have sufficient genetic variability to adapt phenologically and physiologically to warmer and drier conditions. The calcicole flora of the Alps is well placed to withstand the drier conditions that may arise with climatic warming. In the Arctic the polar night will persist whatever changes may take place in the temperature regime. There will therefore always be features of the arctic environment that will be distinctive and can be expected to provide a habitat for a polar flora. The polar bear with its complete dependence on sea ice for hunting seals may disappear. However, cold climate floras by contrast will find sufficient heterogeneity in the arctic and alpine habitats and variation within species to evolve and provide adapted species that may benefit from higher temperatures and longer growing seasons.