Ecohydrological Modeling

The soil-plant system plays a critical role in Earth life support, providing a number of ecosystem services and acting as an interface between the Earth’s subsurface and the atmosphere. For example, photosynthesis and plant transpiration regulate the exchanges of mass (water, carbon, nutrients) and energy at the land surface, affecting groundwater recharge, surface runoff, and atmospheric dynamics. At larger scales, topographic features and their evolution play a major role in the definition of many ecohydrological processes, such as surface/subsurface water redistribution and radiation inputs, which are the main drivers of vegetation and nutrients distribution.

At CHANGE, we develop novel mathematical frameworks accounting for soil-plant dynamics, climatic variability, land erosion and biogeochemistry to describe natural and managed ecosystems, from the plot to the watershed and regional scales. This ultimate goal is to provide quantitative tools for the description of ecohydrological processes and ecosystem dynamics relevant to forestry, agriculture, and climate.

(a) Conceptual description of the soil-plant-atmosphere system. The pathway of water movement from the soil through the plant system into the atmosphere is modeled using a 1D porous medium approach accounting for storage in the plant tissues. Water fluxes are proportional to potential energy gradients between the soil (ψ), the stem base (ψsb), the plant xylem (ψp) and leaves (ψL). The soil compartment is modeled as a 3D porous medium. (b-e) Modeled above and below ground water dynamics: vertical distribution of (b) transpiration, (c) xylem potential, (d) total root water uptake/hydraulic redistribution fluxes, and (e) soil water potential. Modified from Manoli et al., AWR (2017).