Roots of Climate

摘要

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. About two-thirds of the forested area in the Amazon basin experiences a marked dry season from July to November. Even so, rain forests there maintain their greenness year-round, says Jung-Eun Lee, an atmospheric scientist at the University of California, Berkeley. The humidity of the atmosphere just above the treetops in the dry season doesn't differ substantially from that during the rainy season, she notes.