Mongabay: Tree death rates in old-growth forests of the western United States have more more than doubled in recent decades likely because of regional climate warming, report researchers writing in the journal Science. Analyzing records from undisturbed 200-year-old forests in the Pacific Northwest (Oregon, Washington, California, Arizona, Colorado, and New Mexico) and southern British Columbia, Phillip van Mantgem and colleagues found that trees are dying at ever greater rates. Worryingly, …