Place and process in conservation planning for climate change: a reply to Keppel and Wardell-Johnson.

buffering provided by this continuum is the capacity of the refugium [8]. Global climate projections are now unidirectional (e.g., Figure 2 in [5]). The separation of stepping-stone, holdout and microrefugia components (sensu [5]) of the refugium continuum is therefore rendered impotent for conservation planning under anthropogenic climate change. All three proposed components are refugia, as they retain environmental conditions not available in the surrounding landscape. They therefore facilitate the persistence of populations when the surrounding landscape cannot (Figure 1). However, microrefugia have greater capacity as refugia than holdouts or stepping-stones. The capacity of refugia is therefore a more useful concept for landscape level conservation planning under anthropogenic climate change than the separation of refugia into holdouts, microrefugia, and stepping-stones. The latter designation can only be determined retrospectively, after populations have responded. Furthermore, refugial capacity facilitates prioritisation of potential refugia based on their ability to safeguard the survival of species under anthropogenic climate change. For example, quantifying the capacity of refugia allowed determining important refugia in Tasmania, Australia, to the year 2100 under different climate change models [8] and protection of almost 95% of the less-frequently occurring plant taxa.