The biogeography of climate change risk for Scotland's woodland biodiversity: epiphytes

The biodiversity threat of human-induced climate change occurs because shifts in temperature, precipitation, etc. are expected to be large and rapid, while at the same time species vulnerability is increased because of habitat loss and fragmentation, weakening an effective ecological response to climate change. Here, we map both the species exposure to climate change - a decline in suitable climatic condition for areas with diverse lichen epiphyte assemblages - and vulnerability measured as the landscape extent of native woodland, which can provide microclimatic refugia. Choropleth maps for Scotland reveal regional contrasts in the risk for lichen epiphytes; a difference between northeast Scotland, with high exposure to climate change but lower potential vulnerability, and western Scotland with a lower (or more ambiguous) exposure, but high vulnerability because of landscapes with smaller and isolated woodlands. The analysis is general and large scale, relating to species biogeography, but helps to identify key actions at smaller, habitat scales.