Assessing the vulnerability of species richness to anthropogenic climate change in a biodiversity hotspot

Abstract

Aim To compare theoretical approaches towards estimating risks of plant species loss to anthropogenic climate change impacts in a biodiversity hotspot, and to develop a practical method to detect signs of climate change impacts on natural populations.Results A loss of Fynbos biome area of between 51% and 65% is projected by 2050 (depending on the climate scenario used), and roughly 10% of the endemic Proteaceae have ranges restricted to the area lost. Species range projections suggest that a third could suffer complete range dislocation by 2050, and only 5% could retain more than two thirds of their range. Projected changes to individual species ranges could be sufficient to detect climate change impacts within ten years. Main conclusionsThe biome-level approach appears to underestimate the risk of species diversity loss from climate change impacts in the Fynbos Biome because many narrow range endemics suffer range dislocation throughout the biome, and not only in areas identified as biome contractions. We suggest that targeted vulnerable species could be monitored both for early warning signs of climate change and as empirical tests of predictions.

Experimental biogeography: the role of environmental gradients in high geographic diversity in Cape Proteaceae

“…Our results experimentally conWrm the predictions of distribution models (Latimer 2006;Latimer et al 2006) that under current and projected future conditions, many valleys form barriers to dispersal for these and many other CFR Proteaceae (Midgley et al 2002;Thomas et al 2004), contributing to low overall levels of migration in the region (Latimer et al 2005;Schurr et al 2007). Whether lineage splitting in evolutionary time is enhanced by these valleys themselves, which were probably often wetter during much of the Pleistocene, or by plant dispersal traits and their interaction with Wre-driven recruitment, or by shorter generation times relative to resprouting species (Wisheu et al 2000), remain open questions.…”

Extinction risk from climate change

“…For each species we use the modelled association between current climates (such as temperature, precipitation and seasonality) and present-day distributions to estimate current distributional areas [7][8][9][10][11][12] . This 'climate envelope' represents the conditions under which populations of a species currently persist in the face of competitors and natural enemies.…”

“…This 'climate envelope' represents the conditions under which populations of a species currently persist in the face of competitors and natural enemies. Future distributions are estimated by assuming that current envelopes are retained and can be projected for future climate scenarios [7][8][9][10][11][12] . We assume that a species either has no limits to dispersal such that its future distribution becomes the entire area projected by the climate envelope model or that it is incapable of dispersal, in which case the new distribution is the overlap between current and future potential distributions (for example, species with little dispersal or that inhabit fragmented landscapes) 11 .…”

Climate Change and Biodiversity: Some Considerations in Forecasting Shifts in Species' Potential Distributions

“…For instance, several studies have projected future potential distributions of species for conservation purposes (Aspinall and Matthews 1994;Bakkenes et al 2002;Beaumont and Hughes 2002;Burns et al 2003;Dunbar 1998;Erasmus et al 2002;Iverson and Prasad 2001;Meynecke 2004;Midgley et al 2002;Midgley et al 2003;Ortega-Huerta and Peterson 2004;Peterson et al 2002;Skov and Svenning 2004; Tellez-Valdes and Davila- Aranda 2003; Thomas et al 2004;Williams et al 2003), resource management (Bradshaw et al 1992;Clark et al 2001;Holden et al 2003;Loukos et al 2003;Mati 2000;Rafoss and Saethre 2003;Schwartz et al 2001;Sykes 2001;van Staden et al 2004;Williams and Liebhold 2002), public health (Ando 1994; Craig et al 1999;Peterson and Shaw 2003;Wittmann et al 2001), and invasive species (Kriticos et al 2003).…”