Research Directions in Tropical Forest Restoration
In the past few years, numerous global, national, and regional targets have been set to restore millions of hectares of tropical forest to achieve multiple goals, including carbon sequestration, biodiversity conservation, improvements in the quality and supply of water, and support of human livelihoods. To achieve these ambitious goals, restoration decision makers need guiding principles regarding how to invest limited resources for large-scale forest restoration. Research over the past two decades has shown that a host of abiotic and biotic factors can slow tropical forest recovery, but that the specific barriers to and rate of recovery are site specific. Hence, restoration strategies must be carefully selected considering the natural resilience of a given site, localized barriers to recovery, and the ecological and human goals of the project. Despite the substantial advances in our understanding of tropical forest regeneration and restoration, to date neither the scale of scientific studies nor the restoration projects being implemented have matched the ambitious forest landscape restoration plans that are being proposed. I discuss key ways to enhance the success of tropical forest restoration efforts, citing a range of examples to illustrate each point. Specifically, restoration projects need to be planned and evaluated at larger spatial scales and over longer time periods, which requires better integration of the science and practice of forest restoration. Ultimately, forest restoration success hinges on including multiple stakeholders, such as farmers, local communities, local government leaders, regional and national policymakers, and scientists, in the planning, implementation, and evaluation processes. Finally, efforts to improve knowledge sharing across restoration projects in different regions will enhance the likelihood of implementing successful tropical forest restoration projects at the desired scale.