Ecosystem management can mitigate vegetation shifts induced byclimate change in West Africa

Abstract

tThe welfare of people in the tropics and sub-tropics strongly depends on goods and services that savannaecosystems supply, such as food and livestock production, fuel wood, and climate regulation. Flows ofthese services are strongly influenced by climate, land use and their interactions. Savannas cover c. 20%of the Earth’s land surface and changes in the structure and dynamics of savanna vegetation may stronglyinfluence local people’s living conditions, as well as the climate system and global biogeochemical cycles.In this study, we use a dynamic vegetation model, the aDGVM, to explore interactive effects of climateand land use on the vegetation structure and distribution of West African savannas under current andanticipated future environmental conditions. We parameterized the model for West African savannas andextended it by including sub-models to simulate fire management, grazing, and wood cutting. The modelprojects that under future climate without human land use impacts, large savanna areas would shifttoward more wood dominated vegetation due to CO2fertilization effects, increased water use efficiencyand decreased fire activity. However, land use activities could maintain desired vegetation states thatensure fluxes of important ecosystem services, even under anticipated future conditions. Ecosystemmanagement can mitigate climate change impacts on vegetation and delay or avoid undesired vegetationshifts. The results highlight the effects of land use on the future distribution and dynamics of savannas.The identification of management strategies is essential to maintain important ecosystem services underfuture conditions in savannas worldwide.