A new study published in Nature Water has revealed that agricultural regions in 155 countries rely on atmospheric moisture generated by forests in other nations for up to 40 per cent of their annual rainfall. The research highlights how interconnected global food systems are, with forest ecosystems playing a crucial role in sustaining crop production far beyond national boundaries.
The study found that about 18 per cent of rainfall in 105 countries is recycled from their own forests, while moisture from forests worldwide supports 18 per cent of global crop output and 30 per cent of crop exports. This means countries that grow and export food depend heavily on forest cover in upwind regions, creating a complex system of ecological interdependence.
One of the strongest examples of this relationship is South America. Brazil forests supply rainfall to agricultural lands in Peru, Ecuador, Bolivia, Paraguay, Uruguay and Argentina. Together, these regions contribute about 10 per cent of global crop exports. At the same time, Brazil relies on other countries for more than 77 per cent of its own annual crop imports, underlining how forest preservation in one region can benefit agricultural stability elsewhere.
The study also noted that Ukraine’s crop production depends partly on moisture transported from forests in Russia. Any significant changes to these forests could disrupt agricultural output not only in Russia, but also in Ukraine and Kazakhstan. The researchers pointed out that the Russian invasion of Ukraine in 2022 had already demonstrated how sudden disruptions in one major agricultural region can send shockwaves across global food supply chains, affecting food access in the Middle East, Asia and Africa.
Several major agricultural countries, including Brazil, Argentina, Canada, Russia, China and Ukraine, were identified as having high dependence on precipitation recycled from forests. Among them, Brazil stands out, with its forests recycling nearly 9 per cent of the annual rainfall falling on its agricultural zones. This supports 6 per cent of global crop production and 9 per cent of crop exports.
Argentina, meanwhile, receives about 14 per cent of its annual rainfall through transboundary moisture flows, largely from Brazil, and contributes 3 per cent of global crop production and 6 per cent of exports.
The study emphasized that tropical forests such as those in Brazil, Indonesia and the Democratic Republic of Congo supply a relatively high share of rainfall to downwind agricultural regions. Together, forests in the DRC, Bolivia, Brazil, Peru, Canada and Russia support 13 per cent of global crop production and 20 per cent of crop exports.
The researchers warn that this delicate balance could be at risk. Even agricultural regions that meet most of their water needs still depend on small but critical contributions from forest-derived moisture. Any reduction in forest cover could weaken rainfall cycles and jeopardize global food security.