Are trees buffering ecosystems and livelihoods in agricultural landscapes of the Lower Mekong Basin? Consequences for climate-change adaptation

People and ecosystems in the Lower Mekong Basin (LMB) are vulnerable owing to the interaction between unsustainable land-use practices and climate change. This review analyzes 1)) the impacts of continuing land-use and climate changes in the LMB region; and 2) the potential role of increased use of trees in agricultural landscapes to reduce the negative impact of land-use changes. The analysis was based on a review of peer-reviewed literature identified by a keyword search and related unpublished data of the World Agroforestry Centre Thailand. The study confirms that natural resources and ecosystem services— particularly water, soil and biodiversity—are degrading in the LMB. However, trees outside forests, including agroforests, can help buffer both ecosystems and local livelihoods in agricultural landscapes, thereby enhancing their resilience. Several remaining challenges are discussed according to their links to technical, policy and social capital-building issues. Combining local knowledge and scientific knowledge in selecting optimal combinations and spatial arrangements of suitable trees and agroforestry practices is necessary in order to maximize synergies and reduce trade-offs among different ecosystem services, between ecosystem benefits and economic benefits, and between climate-change adaptation and mitigation purposes. Policy recommendations centre on strategies for participatory approaches, on enhancing agroforestry advocacy and on co-interest incentive schemes at farm scale to help address sustainability of agricultural landscapes. Further research is recommended on suitable trees and agroforestry practices to address identified transboundary issues, using a holistic landscape approach with high levels of participation and a nested framework for ecosystem management and monitoring.