Nature World News: Trees are using water more efficiently now than they did two decades back, according to a new study from Harvard University and the U.S. Forest Service.
Researchers said that increased levels of carbon dioxide along and lower levels of water in many parts of the world have increased the efficiency of water usage in trees.
Plants use carbon dioxide from the atmosphere via a process called photosynthesis, where they lose water through leaves. The ratio of water loss to fixed carbon is important...