Determining When Trees Are Drought Stressed

By Richard Waring / On February 18th, 2019
Unlike most annual crops, the roots of long-lived trees can penetrate through soils to great depth to reach water (Figure 1).  If we can’t tell how deeply roots penetrate, how do we determine when trees run out of water?  One way is to monitor the moisture status of leaves and twigs, because these are connected through the sapwood in branches, stems, and roots to water deep underground.
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Dams on the Wild Nujiang

By R. Edward Grumbine / On February 14th, 2011
The central government’s seven-year moratorium on dam building in the Nujiang (“Angry River”) watershed is soon to be lifted and China’s last wild river will be wild no more. Last week, the Chinese National Energy Administration announced that hydropower development was now ready to move forward on the Nu. The river that brought me to Yunnan six years ago is no ordinary river: It is big, wild, and, because of its incredibly steep drop off the southeastern edge of the Tibetan Plateau, features the most raucous rapids that I have ever seen.