Why is Tree Drought Mortality so Hard to Predict?

Widespread tree mortality following droughts has emerged as an environmentally and economically devastating ‘ecological surprise'. It is well established that physiology important in understanding drought-driven mortality; however, the accuracy of predictions based on alone been limited. We propose complicating factors at two levels stymie mortality: (i) organismal-level physiological site obscure drought exposure vulnerability (ii) community-level ecological interactions, particularly with biotic agents whose effects may reverse expectations stress physiology. conclude a path forward emphasizes need for integrative approach to agent dynamics when assessing forest risk morality changing climate.