Abstract:
Global climate change is proceeding at an alarming rate with major ecological and genetic
consequences for biodiversity, particularly in drylands. The response of species to climate change
may difer between intraspecifc genetic groups, with major implications for conservation. We used
molecular data from 10 nuclear and two chloroplast genomes to identify phylogeographic groups
within 746 individuals from 29 populations of Senegalia senegal, a savannah tree species in subSaharan Africa. Three phylogroups are identifed corresponding to Sudano-Sahelian, Zambezian and
Southern African biogeographic regions in West, East and Southern Africa. Genetic diversity was
highest in Southern and Zambesian and lowest in the Sudano-Sahelian phylogroups. Using species
distribution modeling, we infer highly divergent future distributions of the phylogroups under three
climate change scenarios. Climate change will lead to severe reductions of distribution area of the
genetically diverse Zambezian (−41–− 54%) and Southern (− 63–− 82%) phylogroups, but to an increase
for the genetically depauperate Sudano-Sahelian (+ 7– + 26%) phylogroups. This study improves
our understanding of the impact of climate change on the future distribution of this species. This
knowledge is particularly useful for biodiversity management as the conservation of genetic resources
needs to be considered in complementary strategies of in-situ conservation and assisted migration.
