Applying complementarity in ecological restoration

Climate change and biodiversity loss decrease ecosystem functioning and compromise the delivery of nature's contributions to people. Restoration may help address these global challenges, but systems are unique and goals diverse. We review how translating complementarity theory into restoration practice in terrestrial, coastal, and wetland ecosystems can help to meet functional restoration goals. Using the mechanisms that drive complementarity - resource partitioning, abiotic facilitation, and biotic feedbacks - can improve restoration outcomes. These mechanisms can increase functioning by guiding site preparation and species selection, enhancing establishment, and limiting dominant species. We propose a decision tool to match mechanisms with suitable contexts. Degraded ecosystems offer unique opportunities to intentionally reintroduce these processes and observe how they rebuild complexity and function.