Kolloquium: Charlotte Grossiord

As surface temperatures rise, periodic droughts are more often associated with elevated air temperatures leading to a novel type of “atmospheric drought”. Heat exacerbates drought conditions during hot droughts because of increased atmospheric demand for water (i.e., vapor pressure deficit, VPD), resulting in considerable physiological alterations in plants. Recently, hotter droughts have been associated with large-scale tree die-back, reduced forest productivity, and increased wildfire incidence. However, the physiological responses of trees to heat and drought driving carbon, water, and nutrient exchange at multiple time scales are not resolved. While much of our attention has been directed towards forest responses to soil drought acting in isolation, the independent role of high temperature and VPD and the compound impacts of heat and lack of precipitation remain poorly explored. In the Plant Ecology Research Laboratory PERL, we aim to understand the processes driving forest responses to drought exacerbation with global warming. Through a combination of experimental, observational, and modeling approaches at multiple temporal and spatial scales, we assess how heat and drought alter the physiological functions of trees and forests as a whole.