Sven Westermann

In my work, I am interested in the process of root water uptake and its depth of grassland communities as well as drought stress of the vegetation and the prediction of biomass indices (such as Leaf Area Index) by surface models. Since root water uptake is an important flow in local water balancing and in hydrological models, its monitoring and parameterization seems reasonable.

Key questions of my research are:

• How to measure and calculate root water uptake in different soil layers?
• How is the root water uptake depth driven by climate (aridity/seasonality) and treatment (fertilization/land use) gradients?
• How can drought stress of the vegetation be seen by the root water uptake and its depth?
• How well are predictions of vegetation indices from models comapred to available data?

Knowing this could be helpful to improve model results and predictions like in mesoscale hydrological models (mHMExternal link). As an additional step, I want to link the belowground water stress, represented by the root water uptake depth, with structural parameters of the plant community, which are planned to be extracted from photographic information. Such relation might be helpful to include the actual stress of the vegetation in currently existing drought monitoring tools like the German Drough MonitorExternal link.

Westermann, S., A. Hildebrandt, S. Bousetta, S. Thober: Does dynamically modelled leaf area improve predictions of land surface water and carbon fluxes? - Insights into dynamic vegetation modules. Biogeosciences 21(22): 5277–5303, https://doi.org/10.5194/bg-21-5277-2024External link, 2024.