Terrain Slope drives Inter-Seasonal Redistribution of Soil Water

Dryland plants have varying strategies for accessing soil water and nutrients that support net primary production. Important differences in plant-water uptake strategies between shallow-rooted grasses and deep-rooted shrubs allow for their coexistence in arid and semiarid areas. Recent studies point to the role of deep-water sources, including groundwater, bedrock, and vadose zones, on plant productivity. 

This project studies how terrain slopes affect the redistribution of water and other resources between different seasons. The inter-seasonal redistribution proposed here is the carry-over of deep subsurface water from the wet season to the following dry season. The presence of inter-seasonal redistribution in drylands can have important consequences for carbon and water cycles. This project will address these questions using complementary approaches ranging from a transect of eddy covariance sites and remote sensing tools to field base analyses and ecohydrological modelling. These tools complement each other in their scale and their nature from observations to experimentation. 

Results from this project will have important implications for how deep-rooted dryland plants are simulated in modeling platforms operating from local to global scales, for the interpretation of remotely-sensed evapotranspiration and primary productivity during dry periods, and for the current paradigms related to the inter-seasonal variability of the water and carbon cycle in drylands.