Climate-diversity relationships underlying cross-taxon diversity of the African fauna and their implications for conservation

Aim Many taxa show remarkable similarities in their diversity patterns, and these similarities are commonly used to define large-scale conservation priorities. Here, we investigated the relative importance of contemporary climate and climate change since the Last Glacial Maximum for determining the species richness and rarity patterns of four animal taxa. We assessed the extent to which diversity patterns are congruent across taxa because of similar responses to these climatic aspects, and we identify regions that are disproportionately diverse due to their palaeoclimatic stability. Location Sub-Saharan Africa. Time period LGM-contemporary. Major taxa studied Mammal, bird, amphibian and dragonfly species. Methods Diversity patterns were predicted based on their relationships with contemporary climate and Quaternary climate change, respectively. Climate-diversity relationships were modelled with and without accounting for spatial autocorrelation. For raw and predicted diversity patterns, cross-taxon congruence and the coverage of diversity hotspots by protected areas were determined. Results Species richness and rarity of all taxa increased with increasing temperature and precipitation, but also with increasing palaeoclimatic stability. Cross-taxon congruence was higher for predictions based on contemporary climate than for predictions based on Quaternary climate change. Protected areas covered 17%-37% of the species richness and rarity hotspots and approximately 6% fewer hotspots of the underlying signatures of Quaternary climate change (i.e. biodiversity refugia). Main conclusions Both contemporary climate and past climatic changes strongly affect species richness and rarity patterns. However, whereas contemporary climate-diversity relationships are largely congruent across taxa, signatures of Quaternary climate change differ among taxa. Furthermore, protected areas emphasize regions with high species richness and rarity but fewer biodiversity refugia-even less than expected by random placement (<21%). Our results highlight the importance of historical factors for shaping large-scale diversity patterns and the potential of using palaeoclimatic stability-diversity relationships for identifying important conservation areas at the global scale.