Marula (Sclerocarya birrea subsp. caffra, Anacardiaceae) thrives under climate change in sub‐Saharan Africa

Abstract

AbstractClimate change threatens the persistence of some plant species, especially those highly adapted to their microclimates. The aim of the study was to determine the current suitable habitat of marula (Sclerocarya birrea subsp. caffra) and to forecast the habitat under different climate change scenarios. Predictions were made in Maxent using 490 occurrence records, four representative concentration pathways (RCPs) and three general circulation models (GCMs). Variables used were altitude, soil characteristics, monthly precipitation, monthly minimum and maximum temperatures and 19 bioclimatic variables. The current suitable habitat of marula largely occurs in mopane and dry miombo woodlands of southern Africa, including Madagascar. Permutation importance test showed that precipitation in November (30.1%), temperature seasonality (22.1%) and mean temperature of wettest quarter (14.3%) contributed significantly to the model of the current suitable habitat. When forecasted, the suitable habitat expanded under all GCMs and RCPs. On average in 2050, the range expanded by 26.0% (RCP2.6), 33.8% (RCP4.5), 24.8% (RCP6.0) and 42.3% (RCP8.5), while in 2070, it expanded by 30.0% (RCP2.6), 39.9% (RCP4.5), 33.3% (RCP6.0) and 45.1% (RCP8.5). The subspecies is not directly threatened by climate change, but indirect threats remain uncertain.