Refugial capacity defines holdouts, microrefugia and stepping-stones: a response to Hannah et al

Refugia are habitats that populations can retreat to as prevailing climates become inhospitable, and potentially expand from should climates again become favourable [1]. They therefore potentially facilitate the long-term persistence of populations, despite changes in the regional climate. The importance of refugia for the survival of populations under anthropogenic climate change is increasingly recognised [1,2]. As a result, they are now considered keys to conservation planning under climate change [3,4].