Ecohydrology

An interdisciplinary and fast-growing science, ecohydrology aims at understanding the interactions among soil, water, vegetation, microbial biomass, atmosphere, and human societies. We provide a synthetic overview of these complex interactions, by reviewing the developments in ecohydrology following a stochastic modeling approach from the plot to the continental scales. We begin with the soil water balance at a point, which is primarily controlled by the pulsing and intermittent behaviors of rainfall input. It provides the mathematical basis for the analysis of plant water stress, plant biomass, and soil nutrient dynamics. We then review more general ecohydrological feedbacks, including groundwater feedbacks, land-atmosphere interactions at the continental scale, and irrigation in agroecosystem. To analyze the general behaviors of these interactions including the effects of stochastic external forcing, a “macroscopic approach” dealing with reduced order models of the main mean variables is also briefly discussed as a promising tool for future ecohydrological research.