Improving the efficiency of conservation policies with the use of surrogates derived from remotely sensed and ancillary data

摘要

Conservation policies are emerging in many places around the world, many of which involve payment for ecosystem services (PES) schemes. PES schemes provide economic incentives for forgoing land uses that reduce the provision of ecosystem services. The efficiency of such schemes depends not only on the ecosystem services provided by an area but also on the willingness of local people to forgo their land use activities. Targeting land for enrollment in PES schemes on the basis of the potential provision of ecosystem services and on the willingness to forgo certain economic activities, may therefore improve the efficiency of these schemes. The objective of this study was to develop a targeting approach, based on three surrogates derived from remotely sensed and ancillary data, for identifying land to be enrolled in one of the largest PES schemes in the world: China's Grain-to-Green Program (GTGP). The GTGP encourages farmers to return steep hillside cropland to forest by providing cash, grain and tree seedlings. The three surrogates used in the targeting approach were slope index, cropland probability, and GTGP enrollment probability. Combining these surrogates through Bernoulli trials allows targeting areas under cropland, with low opportunity costs for farmers and with potentially high soil erosion and landslide susceptibility. Results of applying the targeting approach in a case study area (Baoxing County, Sichuan Province, China) show that around half of the land currently enrolled is placed in areas with gentle slopes and tend to be located distant from forest areas. This reduces the potential benefits obtained from the GTGP. Targeting land using the proposed approach may double the benefits obtained from the program under the same budget, thus improving its efficiency. The approach may be applied to the entire GTGP implementation area in China and with proper modifications it may also be applicable to similar PES programs around the world.