Impact des changements climatiques sur la répartition géographique des aires favorables à la culture et à la conservation des fruitiers sous-utilisés : cas du tamarinier au Bénin

Impact of climate change on the geographical distrubution of suitable areas for cultivation and conservation of underutilized fruit trees: case study of the tamarind tree in Benin. Climate change may limit integration of Underutilized Agroforestry Fruits Trees (UAFT) into formal cropping systems as a strategy to increase rural household income in Africa. The present study analyzed the potential impact of climate change on the geographical distribution of suitable areas for tamarind (Tamarindus indica L.), an economically important UAFT species. Presence records of the species were collected and combined with bioclimatic data derived from the Worldclim data base and from soil type data. The Maximum Entropy Modeling principle (MAXENT) was used in combination with a Geographic Information System (GIS) to forecast current and future (horizon 2050) suitable habitats for the cultivation and conservation of the species. Three different climate models were used for future predictions (the CCCMA, HadCM3 and CSIRO models) under IPCC scenario A2. Under current conditions, 65% of the national area and 87% of the national protected area network were found to be highly suitable for the cultivation and conservation of local tamarind ecotypes, respectively. It is possible that an increase in rainfall (CCCMA and HadCM3 models) will convert the currently highly suitable zones (semi-arid and subhumid dry) into poorly suitable areas at horizon 2050. A decline in precipitation (CSIRO model) could also convert the currently poorly suitable zones (sub-humid humid) into highly suitable zones. In the case of an aridification of the climate (CSIRO), cultivation and conservation of tamarind could become possible all over Benin and/or require the introduction of ecotypes from more arid areas. The predictive capacity of climatic models is constantly improving and it is therefore recommended that such studies be undertaken in order to better inform decision making for the optimum use of UAFT species.