The role of forests in securing water for agriculture globally

Forests worldwide supply moisture to downwind precipitation through moisture recycling. Agricultural areas located downwind of forests are, hence, susceptible to changes in precipitation caused by upwind forest changes. In fact, human activities have driven extensive forest cover changes in different parts of the world, in different directions, and at different rates. Nevertheless, the forest-agriculture relationship has yet to be systematically quantified and mapped globally. Previous regional studies in South America show that upwind deforestation of the Amazon forest can reduce downwind precipitation and thus decrease agricultural production. A global coverage analysis of forest-agriculture relationship is therefore necessary to identify other hotspot regions where downwind agriculture relies heavily on upwind forests. In this study, we establish the global source-to-sink relationship between forests and their downwind agriculture by analysing 10 years of high resolution (0.25°x0.25°) ERA5-based moisture flows processed by the UTrack moisture tracking model. We assess the seasonality of the reliance on forests considering the growing season of crops cultivated in the downwind regions. Our study provides a global overview of the cross-sectoral and remote dependence of agriculture on forests globally through moisture recycling.