Mauritania is located in a biogeographical crossroad between the Palaearctic and Afro-tropical regions in West Africa, which results in the occurrence of species with distinct biogeographical affinities. The mountains of Adrar Atar, Tagant, Assaba and Afollé are a noticeable species-rich area. Due to alternate historical phases of dry and humid climate in the Sahara, these mountains hold isolated populations of several vertebrates. The current dry stage of the Sahara confines these populations to humid and fragile habitats, rendering populations vulnerable to extinction. However, suitable corridors for dispersal are formed during the rainy season, along raging streams that usually flow to vast plains adjacent to the rock pools, which could inter-connect some of the isolated habitats. Therefore, it can be formulated the hypothesis that dispersal through temporary suitable corridors, with associated gene flow, might attenuate loss of genetic diversity within isolated populations.
This project aims to investigate biogeographical and evolutionary patterns in vertebrates of Mauritania. At a macro-scale, species distribution data of fishes, amphibians, reptiles and mammals are being combined with genetical variability and analysed with Geographical Information Systems (GIS) and ecological modelling in order to: 1) map species distribution and identify biodiversity hotspots; 2) identify environmental factors related with species occurrence and derive models of species-richness distribution; 3) evaluate the effects of climate change on current diversity patterns; 4) uncover phylogenetic relationships and derive historical biogeographical scenarios.
At a micro-scale, species distribution data of selected vertebrates, including fishes (Barbus pobeguini, Tilapia sp.), amphibians (Amietophrynus xeros, Hoplobatrachus occipitalis) and reptiles (Crocodylus suchus) are being combined with genetical variability and analysed with GIS ecological modelling in order to: 5) identify environmental factors related with species occurrence and locate corridors suitable for dispersal between gueltas; 6) determine the role of unpredictable micro-scale events of gene flow in the dynamics of these probable metapopulations.
Funding agency: Fundação para a Ciência e Tecnologia /Programa COMPETE
Budget: 96 714€
Project Code: PTDC/BIA-BEC/099934/2008
Period: 2010 - 2013
Principal investigator: JC Brito