Tucson Citizen: A slight increase in temperature could see drought-stricken trees die five times faster than they do now, a University of Arizona researcher says. Scientists were able for the first time to isolate the impact of increased heat on mature piñon mortality by using the controlled environment in UA’s Biosphere 2, said Henry Adams, lead author of a paper that will appear this week in Proceedings of the National Academy of Sciences. Drought killed at a faster rate piñon trees kept in …