Evapotranspiration (ET) is the main part of water balance in dryland ecosystems, more than 80% of precipitation is usually lost by ET. Rangeland ecosystems transpire at potential rates during periods of high soil moisture, but water losses quickly drop during droughts. So far, the exact point of this ET reduction is unknown and simulation models only use approximate assumptions.
The present project aims to contribute to the understanding of ET dynamics of rangelands during droughts and dry seasons. We want to investigate at which point rangeland ecosystems reduce transpiration and how this can be incorporated into simulation models.
We measure soil moisture beneath different vegetation types (grass, shrubs, trees) and analyse recession patterns of soil moisture at different depths. In parallel, we apply analytical models of different complexity to simulate associated water fluxes.