Modeling the on-site and off-site benefits of Atlantic forest conservation in a Brazilian watershed

Abstract

Payment for Ecosystem Services (PES) programs are used as an approach to promote ecosystem conservation and restoration for hydrologic and other benefits. To quantify these benefits, we modeled the on-site (for rural landowners) and off-site benefits (for downstream water users relying on a large reservoir) of a pioneer municipal level PES project in Brazil established in 2005. We modeled the effects of landscape change on soil loss and sediment export from the Posses watershed using the InVEST model and a methodology that considered real aspects of the landscape and uncertainties in the input data and parameters, as well as economic factors. Results showed that a 3% increase in forest cover coupled with soil conservation practices led to a 0.9–3.5% and a 4.0–13.3% decrease in soil loss and sediment export, respectively. Part of this reduction was due to forest restoration and construction of micro-dams, which were built to improve infiltration close to unpaved roads. We show that PES projects enhance regulating services, providing benefits both onsite and to downstream reservoirs.