Optimizing ecosystem restoration with facilitation cascades.

The United Nations General Assembly designated 2021-2030 as the Decade on Ecosystem Restoration. Meeting this international mandate requires developing, testing, refining, and implementing evidence-based approaches that will significantly increase restoration performance and accessibility. Approaches that apply ecological theories of community organization and species interactions have generally been underused in restoration but can enhance performance and provide opportunities for expanding multispecies conservation. We review how co-occurring habitat-forming species collectively enhance biodiversity, habitat heterogeneity, niche complementarity, and amelioration of physical stress. We show how successive beneficial interactions between foundation species-facilitation cascades-can be used in restoration to increase local biodiversity, enhance and provide additional ecosystem functions, and strengthen resistance to environmental stress and pace of regrowth. Approaches that incorporate co-occurring foundation species' interactions can create a critical step change to advance restoration of biodiverse and resilient ecosystems at the pace and scale required to achieve now seemingly out-of-reach restoration targets.