Charlotte Grossiord

This PhD project at EPFL’s Plant Ecology Research Laboratory (PERL) examines how forest canopy temperature and spectral properties track tree physiological responses to increasing atmospheric drought and soil water limitation. The research aims to understand how forests regulate canopy temperature and water use under drought stress and to develop approaches for mapping forest vulnerability from individual trees to large spatial scales. The work is highly interdisciplinary, combining plant ecophysiology with thermal and spectral remote sensing , UAV observations, and satellite data. A central field site is the Pfynwald experimental forest in Switzerland, where ongoing manipulations make it possible to separate the effects of vapor pressure deficit and soil moisture on mature trees. From there, the project expands to a network of forest sites across Europe and then to continent-scale and global analyses using satellite observations. The student will work on original doctoral research within a collaborative environment spanning EPFL, WSL, and a broader European network of forest research sites. The project includes measurements of sap flow, dendrometers, leaf water potential, gas exchange, chlorophyll fluorescence, and thermal responses, as well as analysis of RGB, multispectral, hyperspectral, and other imagery from fixed cameras and UAVs. The research environment is described as stimulating, interdisciplinary, international, and strongly connected to long-term ecological infrastructure and physiological datasets. Supervision is provided by Prof. Charlotte Grossiord at EPFL, with co-supervision by Dr. Petra D’Odorico and Dr. Helena Vallicrosa from WSL.