Forecasting ecosystem responses to climate change across Africa's Albertine Rift
Climate change is likely to shift the distributions of ecosystems worldwide. Most assessments of climate change are primarily species-focused and do not directly estimate how entire ecosystems may change. Using an ecosystem-based modelling approach, we provide a region-wide climate change vulnerability assessment of the seven major ecosystems across Africa's Albertine Rift. The Albertine Rift is a global biodiversity hotspot, containing more endemic vertebrates than anywhere else in Africa. We used Maxent to estimate each ecosystem's extent using current climate data, then we projected the potential distribution of each ecosystem for 2050 and 2070. We found that suitable conditions for most ecosystems are predicted to contract rapidly in extent and shift upwards in altitude. High-altitude ecosystems and the endemic species they support are at immediate risk, owing to rapid predicted shrinkage in their suitable extent. Only the Combretum-grasslands savannah ecosystem is predicted to expand, with suitable conditions increasing by 32% in area by 2050. The extent and structure of boundary zones between the Rift's ecosystems may change significantly through time, due to the contractions and shifts of the environmental conditions for existing ecosystem distributions. By 2070, 44% of the region could be climatically unsuitable for the current ecosystems. Conservation planning across the Rift will need to account for these ecosystem shifts and rapidly changing boundary zones to ensure the long-term persistence of the many endemic species. Beyond the Albertine Rift, this ecosystem-based modelling technique can be adapted to any terrestrial region, providing critical information for conservation vulnerability assessments.