Researchers have found a way to predict whether or not a forest will survive based on drought conditions – information that can help forest managers deal with climate change.  The researchers from the University of California Davis looked at a drought that caused the loss of tens of millions of trees in the Sierra Nevada forest from 2012 to 2015. In the early years, the trees were doing fine, despite drought conditions. But by 2015, 80% of them were essentially dead.   …If there’s a drought – much like when someone forgets to water a plant – trees will stop growing leaves. Without those leaves, it becomes harder and harder for photosynthesis to occur – until there’s a tipping point when the trees lose their ability to store and convert carbon dioxide. …“Even when the rains come back, if you don’t have any reserves to even perform the basic functions, your (trees) are effectively dead,” Au said. “The water stress depletes your carbon reserves.”