The Sahel is a semi-arid climate zone which stretches across Africa south of the Sahara Desert. Only sparsely covered with native shrubs and trees, the Sahel nonetheless sustains the livelihoods of millions of pastoralists and subsistence farmers. But over the past 40 years, variability in the region’s annual rainfall has increased, marked by dramatic peaks and troughs.  Degradation of land and vegetation is widespread. Understanding the role of trees in Sahelian ecosystems and livelihoods is at the heart of strategies for
responding to climate change now and in the future.