Songwei Wang successfully defended his PhD thesis


Congratulations to Songwei Wang for successfully defending his PhD thesis! In his thesis Songwei investigated g-min, which is the residual conductance of plant surfaces to water vapor after stomatal closure. Understanding g-min is critical for understanding the drought vulnerability of plants. Songwei focussed his investigations on the g-min of temperate tree species. He found that g-min is typically only 1 - 2 % of the maximum vapor conductance of leaves (when stomates are fully open). He also found that g-min is strongly temperature dependent in all investigated species. In contrast, there seems to be little genetic variability of g-min within different genotypes of a species. Songwei used his data to estimate the amount of water that mature trees need during a drought event to prevent desiccation: Depending on the total leaf area of a tree and the atmospheric temperature, this can be up to 30 l a day. Songwei’s detailed experiments contribute significantly to a better understanding of the responses of temperate trees to drought and will be critical for estimating the vulnerabilities of trees to drought induced canopy dieback and mortality.