Ecohydrology of agroforestry systems

Agroforestry systems integrate trees with crops and/or livestock to provide food, fiber, and energy, along with multiple other ecosystem services. Trees have important ecohydrological functions and affect infiltration, runoff, and evapotranspiration, such that, when embedded within agricultural landscapes, they can contribute to the capacity of watersheds to provide clean and reliable water supply. The ecohydrological effects of trees, however, are mediated by their location and spatial configuration within the watershed—which varies by the type of agroforestry system—and the system’s species composition, structure, and management. Here, we describe the primary ecohydrological functions of trees and then review the current literature on the ecohydrology of eight common agroforestry systems. We show that most studies have focused on a single agroforestry system and very few address watershed scale implications. As a result, knowledge on how the ecological characteristics, configuration, spatial location, and management of agroforestry systems within the landscape affect hydrological processes across multiple scales is still limited. Thus, future studies should focus on addressing these knowledge gaps to better inform how agroforestry can provide a strategy for enhancing ecohydrological processes and watershed services.