Assessments needs to support the development of arrangements for Payments for Ecosystem Services from tropical montane cloud forests

ABSTRACT The willingness of beneficiaries to pay for “ecosystem services” will ultimately depend on confidence in the effectiveness of actions taken to ensure their continued delivery at the watershed scale. Key aspects of effectiveness include: (i) the integrity of ecosystem functioning or processes that support service provision, (ii) whether the impacts or benefits are economically significant at the relevant (watershed) scale, and (iii) the effectiveness of institutional arrangements needed to ensure access to benefits by those who pay for them. The biophysical characteristics of the relevant watershed/ecosystem also have implications for the types of institutional arrangements that are possible or necessary to control access to services. Given the dynamic nature of ecosystems, and the potentially long lag time between multiple causes and effects over large spatial areas, the outcomes of management actions are inherently variable, uncertain, and site-specific. In the absence of adequate site-specific assessment, Payments for Ecosystem Services (PES) initiatives are often based on inappropriate generalizations or even myth regarding the hydrological impact of certain types of land-cover changes. Cloud forests in particular are generally assumed to increase the supply of water because they capture water from clouds, beyond that provided by precipitation. However, there is a need for further site-specific assessments, to better define and quantify the extent to which cloud forests account for additional supplies of water compared to other land-cover types that might replace them (e.g. pasture) under various climatic conditions. […]