One of the most important reasons for the degradation of biodiversity, in mountain areas and elsewhere, is that the people who make land use decisions often receive few or no benefits from biodiversity conservation. Understandably, therefore, they generally ignore potential biodiversity benefits when choosing land use practices. The end result is that biodiversity is often lost, as are many other off-site benefits such as the regulation of hydrological flows. Efforts to enhance biodiversity conservation need to take account of the constraints faced by individual land users, who decide what practices to adopt on their land. Over the years, a variety of efforts have been made to boost the profitability of biodiversity-friendly practices for land users, with mixed results. A further approach, which has received increasing attention in recent years, is to provide direct payments for the provision of environmental services such as biodiversity conservation. The simple logic of Payments for Environmental Services (PES) is that compensating land users for the environmental services a given land use provides, makes them more likely to choose that land use rather than another. The Regional Integrated Silvopastoral Ecosystem Management Project, which is being implemented by the World Bank with financing from the Global Environment Facility (GEF), is piloting the use of PES as a means of generating biodiversity conservation and carbon sequestration services in watersheds at three sites in Colombia, Costa Rica, and Nicaragua.