Review of ecosystem service assessments: Pathways for policy integration in Southeast Asia

Southeast Asia (SEA) is one of the most biologically rich regions in the world. The region has achieved rapid economic growth and is undergoing some of the highest rates of urbanisation and agricultural expansion globally. The region's economies are largely based on natural resource exploitation, which has caused considerable tension between natural resource conservation and economic development. Currently, ecosystem services (ES) are degraded in SEA and are projected to decline further over this century. SEA is also one of the global regions expected to be most affected by natural disasters in the future, including those are linked to climate change. Accordingly, ES assessments are attracting growing attention in scientific research and policies in the region, but no comprehensive reviews tracking progress and identifying priorities for future ES assessments in SEA have been produced. Focusing on ES assessments in SEA, we systematically review literature to summarise achievements to date, identify key research gaps, and reveal pathways for policy uptake. Assessment methods are diverse, varying from proxy-based mapping, modelling, economic valuation, and assessments of human perception to combinations among these assessment approaches. Over time, increasing attention has been paid to spatially explicit ES assessments and to integrating stakeholders' perspectives into ES assessment. Some studies have aligned results with policy needs, but their tangible influence on policy still appears limited. To increase policy uptake of ES assessments, greater integration of different methodologies is needed. Furthermore, a regional strategy that facilitates cooperation among SEA countries through shared data accessibility, detailed guidance and capacity building will ensure greater reliability and policy uptake of future ES assessments.