Conservation Biogeography of the Sahara‐Sahel: additional protected areas are needed to secure unique biodiversity

Abstract

Aim Identification of priority conservation areas and evaluation of coverage of the current protected areas are urgently needed to halt the biodiversity loss. Identifying regions combining similar environmental traits (climate regions) and species assemblages (biogroups) is needed for conserving the biodiversity patterns and processes. We identify climate regions and biogroups and map species diversity across the Sahara-Sahel, a large geographical area that exhibits wide environmental heterogeneity and multiple species groups with distinct biogeographical affinities, and evaluate the coverage level of current network of protected areas for biodiversity conservation.Location Sahara-Sahel, Africa.Methods We use spatially explicit climate data with the principal component analysis and model-based clustering techniques to identify climate regions. We use distributions of 1147 terrestrial vertebrates (and of 125 Sahara-Sahel endemics) and apply distance clustering methods to identify biogroups for both species groups. We apply reserve selection algorithms targeting 17% of species distribution, climate regions and biogroups to identify priority areas and gap analysis to assess their representation within the current protected areas.Results Seven climate regions were identified, mostly arranged as latitudinal belts. Concentrations of high species richness were found in the Sahel, but the central Sahara gathers most endemic and threatened species. Ten biogroups (five for endemics) were identified. A wide range of biogroups tend to overlap in specific climate regions. Identified priority areas are inadequately represented in protected areas, and six new top conservation areas are needed to achieve conservation targets.Main conclusions Biodiversity distribution in Sahara-Sahel is spatially structured and apparently related to environmental variation. Although the majority of priority conservation areas are located outside the areas of intense human activities, many cross multiple political borders and require internationally coordinated efforts for implementation and management. Optimized biodiversity conservation solutions at regional scale are needed. Our work contradicts the general idea that deserts are uniform areas and provide options for the conservation of endangered species.

Living on the edge: Ecological and genetic connectivity of the spiny‐footed lizard, Acanthodactylus aureus, confirms the Atlantic Sahara desert as a biogeographic corridor and centre of lineage diversification

“…The Atlantic Ocean's proximity creates different climatic conditions when compared to inland areas at the same latitudes: coastal temperatures are milder and prone to less variation, and despite the low precipitation, the sea fog and dew help vegetation growth (Dinerstein et al., ). These environmental conditions provide continuous distributions along the area for several taxonomical groups (Brito et al., ). A number of taxa are fully or nearly endemic to the Atlantic Sahara, such as the reptiles Acanthodactylus aureus (Crochet, Geniez, & Ineich, ) and Tarentola chazaliae (Trape, Trape, & Chirio, ), and the mammals Crocidura tarfayaensis (Vogel et al., ) and Gerbillus occiduus (Ndiaye et al., ).…”

Classifying biogeographic realms of the endemic fauna in the Afro‐Arabian region

“…Biogeographic regionalization analysis has been successfully applied to identify biodiversity patterns and is considered a promising approach for prioritizing the conservation efforts (Brito et al, 2016;Kreft & Jetz, 2010;Vale et al, 2016). Biogeographic regionalization groups geographic regions into meaningful clusters (henceforth referred to as the "bioregion") based on the dissimilarity of the species assemblages (González-Orozco, Laffan, Knerr, & Miller, 2013;Rodrigues, Fig ueira, Vaz Pinto, Araújo, & Beja, 2015).…”

Network‐ and distance‐based methods in bioregionalization processes at regional scale: An application to the terrestrial mammals of Iran

“…Likewise, quantifying representation levels of distinct biogeographical units and climate regions in the current network of Protected Areas (PAs) (covering c . 10% of Iran; DoE‐GIS, ) is essential to flag potential representation gaps (Brito et al, ; Dinerstein et al, ).…”

“…As such, identification of climate regions, i.e. areas with geographically distinct climatic patterns, can help defining priority areas for protection of climatic refugia or evolutionary processes (Brito et al, 2016;Michalak, Lawler, Roberts, & Carroll, 2018). Bioregions and climate regions can serve as conservation units and provide a framework for regional biodiversity conservation planning.…”

“…As such, a quantitative assessment of regional biogeographical units is necessary to uncover the representative array of major distinct ecosystems, vital for conservation planning. Likewise, quantifying representation levels of distinct biogeographical units and climate regions in the current network of Protected Areas (PAs) (covering c. 10% of Iran; DoE-GIS, 2016) is essential to flag potential representation gaps (Brito et al, 2016;Dinerstein et al, 2017).…”