Interactions between root water uptake, groundwater levels, and soil moisture dynamics in Tuolumne Meadows, Yosemite National Park, CA

In high elevation meadow environments within the Sierra Nevada Mountains soil moisture is controlled by the position of the water table and the partitioning of evapotranspiration through root water uptake and evaporation at the land surface. Because of the relative lack of precipitation over the growing season plant communities rely on stored soil moisture and shallow groundwater during the dry summer months. Field result, from Tuolumne Meadows show both temporally and spatially dynamic soil moisture patterning caused by the timing of spring snowmelt and subsequent drying of the meadow. Through the use of numerical modeling we are able to examine the temporal and spatial distribution of soil moisture and the potential impact on water use by plant communities. Results highlight the importance of both the position of the water table in the early growing season and sediment layering within the meadow on plant water up take. These results have implications for current meadow restorations projects and stress the importance of designing projects that focus on soil moisture dynamics in order to supply sufficient water for native plant communities.