Impact of climat change on the dynamics of potential habitat of Balanites aegyptiaca (L.) Del. in Niger

Abstract

The objective of this study is to model the potential distribution of Balanites aegyptiaca under the influence of climate change in Niger. The principle of maximum entropy (MaxEnt) was used to determine the favorable habitats of the species based on variations in current and future climatic conditions (horizon 2050). The presence data of the species combined with bioclimatic data derived from the Worldclim database allowed to generate three climate models for future projections (the CCCMA, CSIRO and HadCM3 models) under the A2 scenario of the IPCC. The coldest quarter precipitation (BIO19) and the wettest period precipitation (BIO13) are the environmental variables that most contributed to the model prediction. Under current climatic conditions, 67.7% of the Nigerien territory is very favorable to the development of Balanites aegyptiaca. The CCCMA and HadCM3 models which predict an increase in precipitation by 2050 as well as the CSIRO model which predicts a decrease for this same horizon show that very favorable habitats will be converted into moderately favorable habitats. Terrestrial protected areas in Niger, located mainly in the Sahelo-Sudanian region, are more effective for the conservation of Balanites aegyptiaca both under current climatic conditions and by 2050. These are mainly the Tamou and Gadbédji total wildlife reserves. The present study shows that Balanites aegyptiaca is one of the few species that is well adapted to the arid conditions of the Sahelo-Sudanian zone. The results of this study constitute a tool that can serve as a basis for the conservation and management of natural stands of Balanites aegyptiaca.

 Keywords: Balanites aegyptiaca, MaxEnt, ecological niche, climate change, protected areas, Niger.