Alternatives for improving Payment for Ecosystem Services (PES) effectiveness on water resources

Ecosystem services (ES) are the benefits ecosystems provide to society. These services grant the necessary conditions for sustaining life and influence human well-being in all dimensions, including providing basic needs, health, and freedom of choice and action (MEA 2005). ES include all contributions of nature to humans, and these are relative according to the context and the existence of alternatives (IPBES 2019). Ecosystem degradation jeopardizes the sustainable provision of these services. In this context, Payment for Ecosystem Services (PES) schemes arose as policy instruments that promote pro-environmental land use through financial incentives for actions that improve, maintain, or maximize the provision of ES (Kim et al. 2016). Since the late 1990s, PES schemes have spread worldwide, adopting different payment types, scales, and conservation objectives (Salzmann et al. 2018). Some incentivized activities are forest conservation, watershed protection, biodiversity conservation, and carbon (C) sequestration and storage. One central area for improvement of most PES is their need for ES measurement. Due to the technical difficulty and high cost of measuring and monitoring ES periodically, most PES only monitor land uses and practices granted under PES contracts. Overall, PES have been based on the premise that, by incentivizing forest conservation and reforestation of nonforest areas, the flow of ES of interest to society is maintained or increased. However, this presumed correlation may be nonlinear, asynchronous in time and space, could involve trade-offs among ES at the landscape scale, and, in the worst-case scenario, the …