Large-scale recovery in Costa Rica’s payment for ecosystem service program

Abstract

AbstractCosta Rica implemented the world’s first national-scale Payment for Ecosystem Service (PES) program in 1996 and now protects over 200,000 hectares. By distributing wealth towards local land-stewards, Costa Rica’s program has helped to limit deforestation at a national scale, but the large-scale ecological implications have yet remained unclear. Here, we use a massive ecoacoustic dataset to evaluate how this program has impacted the ecological integrity of PES forests across the entire Nicoya Peninsula. At the times and frequencies that are indicative of native biological activity, we reveal dramatic increases in the integrity of PES soundscapes, relative to those of natural protected areas. Specifically, natural regeneration sites were 97.79% more acoustically similar to reference forests (absolute mean similarity of 0.539) than they were to disturbed pastures, while acoustic recovery of plantations lags behind (79.66%; 0.489). These findings are strongly suggestive of large-scale ecological recovery, constituting some of the most robust evidence to date that restoration initiatives can benefit biodiversity on large spatial scales.Study overviewCosta Rica’s PES program pays landowners to encourage forest recovery and compensate them for opportunity costs. Most payments subsidize land ‘conservation’, in which participants allow existing forests to naturally regenerate. Some payments are also offered to produce timber through ‘plantations’, which are often monocultures of exotic tree species. Despite the program’s importance to Costa Rica’s conservation efforts, little is known about whether these forest systems are recovering their natural characteristics. To investigate the dynamics of the PES program, we recorded continuous 6-day soundscapes in 119 sites across the Nicoya Peninsula of Costa Rica (Supplementary Figure 1). Specifically, we characterized the soundscapes across 4 land-use types: (i) 19 reference pastures, (ii) 43 PES monoculture tree plantations, (iii) 39 PES natural regeneration sites, and (iv) 18 reference forests. Sites from each land-use type are distributed across the Nicoya Peninsula’s climate and edaphic gradient, allowing us to capture substantial variation in ecological outcomes. We determined the areas of acoustic space where most animals vocalize and where ecological responses to recovery were most likely to be detected (Figure 1). We then identified how and to what extent the soundscapes of natural regeneration and plantation sites had changed over the last 27 years. We find evidence that naturally regenerating forests within the PES have recovered substantially when compared to reference forests, while plantation systems lag behind (Figure 3). Our findings reaffirm the importance of ecosystem conservation, while suggesting redistributive policy mechanisms can accelerate nature protection at scale.