Open ecosystems restoration: a global review shows biases and mismatches between theory and practice

Ecological restoration aims to recover the structure, biodiversity, and function of degraded ecosystems. However, open ecosystems have been largely overlooked in restoration, and the extent of theory‐based restoration is unclear. We systematically review papers on open ecosystems restoration from 2011 to 2021, examining publication trends with data on restored site age, size, indicators, and assessment frequency. We also explore the relationships between interventions, indicators, and ecological concepts. By analyzing 343 papers, we found that open ecosystems restoration is concentrated in North America and Europe, with nearly 75% of restored areas originating in these continents. Restored areas are small, assessed for a short duration, with a plethora of indicators and no establishment of clear control or reference areas for meaningful comparisons. Common open ecosystems restoration sites interventions involved trees and shrubs management, soil management, seeding, and transfer of plant material as the main interventions. From our analyzed papers, we found that 30% of them mentioned any ecological concepts, with community assembly and succession being the most mentioned ones. Furthermore, our exploratory analysis revealed no relationship between interventions, indicators, and ecological concepts, suggesting a widespread mismatch between theory and practice. As the Decade for Ecosystem Restoration unfolds, we call practitioners, researchers, and stakeholders working on open ecosystems to address challenges and curtail widespread biases. Despite the uniqueness of each restoration project, a clear, well‐planned design encompassing site‐specific variables and solid theoretical bases is expected to enhance restoration outcomes, optimizing costs and biodiversity gains.