糖心视频

Forests play a crucial role in providing precipitation to agricultural areas, importantly supporting crop production and global trade activities. A recent study in Nature Water emphasizes that to manage global food risks, it is essential to conserve forests located upwind of agricultural regions.

In recent decades, climate extremes have become more frequent and intense, leading to over half of the loss incidences in crop production worldwide. Concurrently, intense deforestation has diminished forests' ability to supply stable moisture to agricultural areas, resulting in reduced evaporation, less precipitation, and altered rainy seasons.

The moisture flows connect forests not only with the agricultural areas within the countries but also across the borders, according to a study by scholars from the Stockholm Resilience Center and Wageningen University & Research, among others. To understand how forests contribute to global crop production and exports, the researchers compared moisture flows with crop production and export data.

This interdependence is well illustrated by the case of Brazil. In addition to providing moisture to its own agricultural areas, Brazilian forests influence crop production in Peru, Ecuador, Bolivia, Paraguay, Uruguay, and Argentina.

"These countries account for 10% of global crop exports accounted in the study, including shipments to Europe, Asia, Africa, and Oceania. Thus, nations importing crops from South American countries are indirectly reliant on moisture from Brazilian forests," explains lead author Agnes Pranindita, a former Wageningen graduate, who currently works at Stockholm Resilience Center and collaborates with Wageningen University & Research on this project.

The study reveals that overall, croplands in 155 countries depend on moisture from forests located in other countries for up to 40% of their annual precipitation. For example, the success of crop production and export from central Africa is highly dependent on effective forest conservation practices in the Democratic Republic of the Congo and the Central African Republic.

However, some of the "dependent" countries contribute back to the countries which provide the moisture. For example, Brazil supplies moisture to Paraguay, Uruguay and Argentina, and, at the same time, it imports crops from these countries. In this case, the conservation practices in Brazil would have direct benefits to its neighbors and an indirect influence on its own crop supply.

Lastly, researchers observe that the moisture dependency between two countries can also affect crop supply to a third-party country: "It is well known that when crop production and export in a certain region are disrupted, as we have seen since the Russian invasion of Ukraine in 2022, it affects the supply of staple cereals to other regions, such as the Middle East, Asia and Africa in the case of Ukraine," adds researcher Ryan Teuling from Wageningen University & Research.

"But what is less known, is that crop production in Ukraine in turn depends on moisture being supplied by forests in Russia."

The study's findings underscore the importance of forest conservation for the future crop supply: "Effective forest conservation practices could help to mitigate the escalating climate-induced risks threatening agriculture," concludes researcher Lan Wang-Erlandsson.