PhysOrg: Billions of trees killed in the wake of mountain pine beetle infestations, ranging from Mexico to Alaska, have not resulted in a large spike in carbon dioxide released into the atmosphere, contrary to predictions, a UA-led study has found. Massive tree die-offs release less carbon into the atmosphere than previously thought, new research led by the University of Arizona suggests. Across the world, trees are dying in increasing numbers, most likely in the wake of a climate changing toward drier...