Climate change is already changing the distribution of many species. In general species are moving further north, and higher up as a warming climate means they can exploit previously inhospitable environments. This can be positive in that some species will increase their ranges, however for as many species that will benefit, others, those primarily adapted to colder climates may suffer. But it’s not all about gradual warming. Climate change is also projected to bring an increased incidence of extreme weather, whether it be cold winters, drought or heat waves, and these can have severe impacts on populations.
One action often suggested is to reduce the fragmentation of habitats to enable species to move more easily through the landscape. Another frequent suggestion is that we should focus on ensuring that existing patches are of optimum quality and maximum size. Both these approaches are based on sound ecological theory, but in practice until recently there was little evidence to support their role in adaptation.
However a recent paper published by a group from BTO, CEH and Natural England presents some evidence to support the role of both reducing isolation and increasing patch size in increasing the resilience of some woodland bird species to climate change.
The group found that populations of woodland ‘generalist’ birds were most sensitive to extreme weather, in this case colder winters, if they were located within fragmented landscapes with large distances between patches.
Along with this, woodland ‘specialist’ birds recovered more rapidly following cold winters on large woodland sites.
So we need to find ways to have bigger patches of good quality woodland, closer together in the countryside. A strategic, partnership approach – who’s interested?