Assessment of Climate Change Impact on Future Distribution of Palm Trees in Niger, West Africa

Palm trees are multi-purpose species that are involved in several socio-economic and cultural aspects of Niger people. Indeed, palm trees significantly improve local population life. This study aims to assess the impact of future climate change on the geographical distribution of Borassus aethiopum Mart., Hyphaene thebaica (L.) Mart. and Phoenix dactylifera L. and to determine the suitable habitats for the conservation and sustainable management of these species in Niger. The maxEnt approach was used to model the species distribution. Four climatic models of CHELSA V2.1 were used: gfdl-esm4, ipsl-cm6a-lr, mpi-esm1-2h, mri-esm2-0 under two scenarios: ssp1-2.6 and ssp5-8.5 by periods 2011–2040 and 2041–2070. The mean AUC was 0.93 for Borassus aethiopum (0.93), 0.86 for Hyphaene thebaica, and 0.87 for Phoenix dactylifera. TSS test mean were 0.85, 0.69, and 0.75 respectively for Borassus aethiopum, Hyphaene thebaica, and Phoenix dactylifera. The current distribution for highly suitable habitats was 33,223 km2 (2.22%), 159,495 km2 (10.66%), and 108,189 km2 (7%) respectively for Borassus aethiopum, Hyphaene thebaica, and Phoenix dactylifera. The moderately suitable habitats were 83,019 km2 (5.55%) for Borassus aethiopum, 86,239 km2 (5.76%) for Hyphaene thebaica and 66,426 km2 (4%) Phoenix dactylifera. The lowly suitable habitats were 137,859 km2 (9.21%), 201,609 km2 (13.48%), and 333,181 km2 (22%) respectively Borassus aethiopum, Hyphaene thebaica, and Phoenix dactylifera. The highly and moderately suitable habitats for Borassus aethiopum will increase over the period 2011–2040 and 2041–2070. The highly suitable habitats of Hyphaene thebaica will be highly decreased by the period 2011–2040 and 2041–2070 than the other suitable habitats. All suitable habitats and all models of Phoenix dactylifera will decrease under the period 2041–2070. Phoenix dactylifera and Hyphaene thebaica will be much more affected by future climate change. This will also affect production rates for farmers in Niger.