Vale CG, Santos X, Brito JC



The common perception of the Desert biome is that it generally constitutes remote areas of low diversity. However, the world's largest warm desert, the Sahara, together with the neighboring arid Sahel exhibit high topographic and climate heterogeneity and have experienced strong climatic oscillations that have shaped land-cover and biodiversity distribution. This review summarizes the knowledge on the Sahara-Sahel biodiversity patterns based on the distribution of terrestrial vertebrate species richness (also called α-diversity) and species turnover or the change in species among sites (β-diversity). The distribution of α-diversity in the Sahara-Sahel follows the general latitudinal gradient, with higher percentage of species found in the southern Sahel region. This broad latitudinal gradient pattern is disrupted by higher number of species distributed along hypothesized ecological corridors and refugia. The distribution of β-diversity highlights the boundaries of the Sahara-Sahel hotspots of species richness. At local scale, recent studies have emphasized the natural value of isolated and residual wetlands (oases, lakes, and seasonal rivers) of high productivity, acting as refugia for relict populations. Among these wetlands, mountain rock-pools constitute local hotspots of biodiversity.



Journal: Reference Module in Earth Systems and Environmental Sciences

DOI: 10.1016/B978-0-12-409548-9.11927-X