Quantifying the capacity of climate change refugia for biodiversity
Refugia are habitats that components of biodiversity retreat to, persist in and can potentially expand from under changing environmental conditions. Identifying and protecting such refugia is considered a priority for conservation under projected anthropogenic climate change, because of their demonstrated ability to facilitate the survival of biota under adverse conditions. However, refugia differ in their potential for facilitating species persistence (i.e., their “capacity”). Therefore, to effectively include refugia in conservation planning, their capacity needs to be quantified. We develop a flexible framework to quantify the capacity of refugia and prioritize them for conservation planning. We then use an integrated, semi-mechanistic modelling technique to illustrate how this approach can be implemented to identify refugia for the native and endemic plant diversity of Tasmania, Australia.
The flexible framework consists of three steps: (1) definition of relevant scope, scale, and resolution; (2) identification of refugia and quantification of their capacity; and (3) prioritization of refugia for conservation. We used environmental stability, microclimatic heterogeneity, size, and accessibility of the refugium as key indicators of its capacity. For Tasmanian biodiversity and using semi-mechanistic modelling, we found the climate change refugia with the highest capacity to occur in cool, wet, and topographically complex environments, which are therefore high priorities for biodiversity conservation and management.