A Framework Model to Assess Ecosystem Functioning in Agriculture Watersheds: The Case of Córrego Rico, Brazil

Sustainability is essential to Earth systems, but inadequate landscape planning makes it a challenge to modern societies. To help improving sustainable land use in watersheds, this study merged the so-called Conservation Use Potential (CUP) method with an Ecosystem Services (ES) accounting method. The compound CUP-ES method embeds a novel multifunctionality index, called Ecosystem Functioning Potential (EFP), which helps making sustainable land use actionable through Payment for Environmental Services (PES) schemes. The CUP and ES were assessed by a multicriteria analysis connecting a diversity of parameters, and regionalized using map algebra and zonal statistics in a Geographic Information System. The novelty of CUP-ES and EFP analyses rely on their ability to rank areas for practical interventions in the watershed: (a) land use conversions such as extensive reforestation or agroforestry systems; (b) landscape stabilization through erosion control; (c) conservationist soil management; and (d) PES to ensure the protection of natural capital and improve the supply of ecosystem services. The CUP-ES-EFP framework was applied to the Córrego Rico Watershed (CRW), located in the state of São Paulo, Brazil. The multicriteria analysis assigned different ratings and weights to soil use potential parameters (soil type, bedrock, terrain slope) as well as to provisioning (water resources) and supporting (soil carbon stock and biodiversity) ecosystem services. The key results showed that most sub-basins within the CRW correspond to moderately managed production systems (sugarcane), as they preserve ecosystem services notwithstanding the intensive use. Thus, they were recommended for conservationist soil management according to the CUP-ES interpretation. The spatial distribution of EFP suggested the implementation of PES in some areas, given their role as water resources suppliers. The main conclusion was that, the CUP-ES-EFP framework proved efficient for sustainable land use planning, being regarded as potential decision-making tool. In that context, sustainability of CRW could be reached through the balance of protected areas (the headwaters), seen as net suppliers of ES, and food production systems (the lower lands), mostly regarded as net ES consumers.