Ecosystem services from Southern African woodlands and their future under global change

摘要

Miombo and mopane woodlands are the dominant land cover in southern Africa. Ecosystem services from these woodlands support the livelihoods of 100 M rural people and 50 M urban dwellers, and to others beyond the region. Provisioning services contribute $9±2 billion year-1 to rural livelihoods; 76% of energy used in the region is derived from woodlands; and traded woodfuels have an annual value of $780 M. Woodlands support much of the region’s agriculture through transfers of nutrients to fields and shifting cultivation. Woodlands store 18-24 PgC carbon, and harbour a unique and diverse flora and fauna that provides spiritual succour and attracts tourists. Longstanding processes that will impact service provision are the expansion of croplands (0.1 M km2; 2000-2014), harvesting of woodfuels (93 M tonnes year-1) and changing access arrangements. Novel, exogenous changes include large-scale land acquisitions (0.07 M km2; 2000-2015), climate change, and rising CO2. The net ecological response to these changes is poorly constrained, as they act in different directions, and differentially on trees and grasses, leading to uncertainty in future service provision. Land use change and socio-political dynamics are likely to be dominant forces of change in the short term, but important land use dynamics remain unquantified.