Data from: Ecological restoration success is higher for natural regeneration than for active restoration in tropical forests

Is active restoration the best approach to achieve ecological restoration success (the return to a reference condition, that is, old-growth forest) when compared to natural regeneration in tropical forests? Our meta-analysis of 133 studies demonstrated that natural regeneration surpasses active restoration in achieving tropical forest restoration success for all three biodiversity groups (plants, birds, and invertebrates) and five measures of vegetation structure (cover, density, litter, biomass, and height) tested. Restoration success for biodiversity and vegetation structure were 34 to 56% and 19 to 56% higher in natural regeneration than in active restoration systems, respectively, after controlling for key biotic and abiotic factors (forest amount, precipitation, time elapsed since restoration started, and past disturbance). Biodiversity responses were based primarily on ecological metrics of abundance and species richness (74%), both of which take far less time to achieve restoration success than similarity and composition. This finding challenges the widely held notion that natural forest regeneration has limited conservation value and that active restoration should be the default ecological restoration strategy. The proposition that active restoration achieves greater restoration success than natural regeneration may have arisen because of comparisons lacking controlled biotic and abiotic factors. We did not find any difference between active restoration and natural regeneration outcomes for vegetation structure when we did not control for these factors. Future policy priorities should align the identified patterns of biophysical and ecological conditions where each or both restoration approaches are more successful, cost-effective, and compatible with socioeconomic incentives for tropical forest restoration.在热带森林的生态修复中，相较于自然更新（natural regeneration），主动修复（active restoration）是否为达成修复成功（即恢复至参照状态，也就是原始老龄林）的最优路径？我们针对133项研究开展的荟萃分析（meta-analysis）结果显示，在受试的3类生物多样性类群（植物、鸟类与无脊椎动物）以及5项植被结构指标（盖度、密度、枯落物量、生物量与高度）中，自然更新在实现热带森林修复成功方面均优于主动修复。在控制关键生物与非生物因子（森林面积、降水量、修复启动时长以及既往干扰情况）后，自然更新样地的生物多样性修复成功率较主动修复样地高出34%至56%，植被结构修复成功率则高出19%至56%。生物多样性响应指标主要基于丰度与物种丰富度这两类生态度量（占比74%），相较于群落相似性与物种组成，这两类指标所需的修复成功达成时间要短得多。这一研究结果驳斥了广为流传的两种认知：一是天然林更新的保育价值有限，二是主动修复应作为生态修复的默认策略。认为主动修复的修复效果优于自然更新的论断，可能源于此前的比较研究未对生物与非生物因子进行控制。当未对上述因子进行控制时，我们未发现主动修复与自然更新在植被结构修复效果上存在显著差异。未来的政策制定应匹配已探明的生物物理与生态条件特征，针对不同（或两类）修复方案各自更具优势的场景，制定兼具成本效益、且契合热带森林修复社会经济激励机制的优先行动方向。