Roots of Climate: Plants’ water transport cools Amazon basin

Field tests in the Amazon have for the first time measured daily and seasonal movements of soil moisture through the deep roots of trees. This water management, which enables the plants to maintain photosynthesis during the region’s long dry season, significantly affects the area’s climate, the new research suggests.

COOL ZONES. Transfer of moisture by plants from deep layers of soil to the surface cools some regions, such as the rain forests of the Amazon basin, by as much as 2°C (dark blue), according to a comparison of climate models that do and don’t include that phenomenon.