Impact of Climate Change on the Distribution of Vachellia tortilis subsp. raddiana (Savi) Kyal. and Boatwr. In Eastern Niger

Abstract

The multipurpose species Vachellia tortilis (umbrella thorn) is a woody plant whose parts are extensively used for food, feed, traditional pharmacopoeia, energy, and handicrafts. The species also provides multiple ecological benefits. This study aims at assessing the impact of climate change on the geographical distribution of V. tortilis in Eastern Niger, by analyzing the climatic factors influencing its current distribution and predicting its future distribution areas under different climate scenarios. Species occurrence data were collected and combined with bioclimatic data derived from the WorldClim database and vegetation data. Two climate models were used for future projections (RCP 4.5 and RCP 8.5). Results from the Jackknife test showed that five variables contribute significantly to the models. V. tortilis has a wide distribution, being present in all agroecological zones, with a high concentration in the Sahelian zone. Future climate projections for 2055 indicate an increase in the current vegetational range of species of 19.8% to over 30%. However, the potential distribution of the species is not compromised by the 2055 climate projections or local disturbance factors. The species will remain highly suitable for the study area, continuing to provide all the ecosystem services it offers.