Integrating ecosystem services in spatial planning and strategic environmental assessment: The role of the cascade model

Over the last decade, the ecosystem service (ES) approach has gained increasing attention because it offers important advantages for enhancing decision-making. However, a key and remaining challenge is how to implement this approach in real-world decision problems. This challenge is particularly relevant for governance and policy instruments, such as spatial planning and strategic environmental assessment (SEA), where including the ES approach is recognized as a great opportunity for achieving sustainable development goals. Consequently, this opinion paper proposes the use of the ES cascade model, as the basis to develop a framework that makes explicit the links among development objectives, sustainability goals, and the overall dependency on the ES supply. The main reflections address the need for a collaborative work between policy and science as a cross-cutting aspect for an interactive, participative and transparent research process that allows 1) the development of spatial indicators of ecosystem structures, 2) valuation and spatial modeling of ES, 3) identification of benefits and networks of actors, 4) the definition of values and, 5) generation of scenarios for a trade-off assessment of development alternatives. Finally, in addition to the information and knowledge generation regarding multi-scale relationships of the different components of the ES cascade, real-world evidence is urgently needed.