A voluntary transaction whereby a well-defined land-use service is ‘bought’ by an ecosystem service buyer from an ecosystem service provider if and only if the ecosystem service provider secures ecosystem service provision (i.e., based on conditionality).
The PES concept builds on the “provider gets” principle which differs from the “polluter pays” one as it is focused on the idea that ecosystem service providers be paid for positive externalities they provide rather than on the idea that polluters pay to compensate for negative externalities they generate.
Source: Centre for International Forestry Research – Occasional Paper #42 (2005) Payments for environmental services.
