Nature Bests Humans at Restoring Tropical Forests: The spontaneous recovery of native tree species is more successful in restoring tropical forests than human interventions like planting seedlings, a new study reports. This finding challenges the widely-held notion that natural forest regeneration has limited conservation value and that active restoration, driven by human interventions, should be the default strategy. The relatively limited number of past studies on these restoration strategies have often been conducted on small scales and have yielded contradictory results, the authors say. To further investigate whether active restoration or natural regeneration is the best approach for tropical forest restoration, Renato Crouzeilles conducted a meta-analysis of 133 studies and compared the recovery of biodiversity and forest structure between sites classified as active restoration and natural regeneration. They found natural regeneration was more effective in restoring plant, bird, and invertebrate biodiversity and vegetation growth, measured by criteria such as plant density and height. What's more, natural regeneration is a lower-cost approach. Previous analyses that report opposite findings may not have accounted for factors such as precipitation, or time elapsed since restoration started, Crouzeilles et al. write. The authors also note some forests may be unsuitable for natural regeneration, and in those cases active restoration may be a desirable approach. In addition, mixing both restoration approaches might be key to attaining a richer species pool.