Seminar: Xue Feng

Plant transpiration is one of the most important components of the global water cycle. The way transpiration rates decrease under water stress is often represented in land-atmosphere models through a simple correction factor based on soil moisture. While this simple model is computationally efficient and can be easily parameterized, it fails to capture the interactions between environmental and physiological drivers and becomes problematic under intense drought. In this talk, I will share recent work that explores the limits of this soil moisture correction-based model. I will first demonstrate that it neglects to capture the role of plant hydraulic transport in regulating transpiration, a key mechanism for linking the effects of atmospheric and soil water stress on plants. Then, I will show that this may lead to uncertainties in how soil water stress is diagnosed in forested ecosystems based on eddy covariance data. Finally, I will share a data-informed approach for inferring the necessary plant traits to improve the representation of plant water regulation.