A major challenge for forest landscape restoration initiatives is the lack of quantitative evidence on how social factors drive environmental outcomes. Here we conduct a transdisciplinary quantitative analysis of the environmental and social drivers of tree biomass accumulation across 639 smallholder farms restoring native tree species in Mexico, Uganda and Mozambique. We use environmental and social data to assess the relative effects of key hypothesised drivers on aboveground biomass accumulation at the farm-level over ten years. We supplement this with a qualitative analysis of perspectives from local farmers and agroforestry technicians on the potential causal mechanisms of the observed social effects. We find that the material wellbeing of farmers (e.g. assets) and access to agroforestry knowledge explain as much variation in biomass as water availability. Local perspectives suggest that this is caused by the higher adaptive capacity of some farmers and their associated ability to respond to social-ecological shocks and stresses. Additionally, the variation in biomass between farms increased over time. Local perspectives suggested that this was caused by emergent exogenous and stochastic influences which cannot be reliably predicted in technical analyses and guidance. To deal with this persistent uncertainty, local perspectives emphasised the need for flexible and adaptive processes at the farm- and village-levels. The consistency of these findings across three countries suggests these findings are relevant to similar forest restoration interventions. Our findings provide novel quantitative evidence of a social-ecological pathway where the adaptive capacity of local land users can improve ecological processes. Our findings emphasize the need for forest restoration programmes to prioritise investment in the capabilities of local land users, and to ensure that rules support, rather than hinder, adaptive management.

中文翻译：

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社会与环境：小农森林景观恢复计划中树木生物量的驱动因素

森林景观恢复计划的一个主要挑战是缺乏关于社会因素如何推动环境结果的定量证据。在这里，我们对墨西哥、乌干达和莫桑比克 639 个恢复本地树种的小农农场的树木生物量积累的环境和社会驱动因素进行了跨学科定量分析。我们使用环境和社会数据来评估十年间关键假设驱动因素对农场一级地上生物量积累的相对影响。我们通过对当地农民和农林业技术人员对观察到的社会影响的潜在因果机制的观点进行定性分析来补充这一点。我们发现农民的物质福利（例如 资产）和获得农林业知识的机会解释了生物量的变化与可用水量一样多。当地观点表明，这是由于一些农民具有较高的适应能力以及他们应对社会生态冲击和压力的相关能力造成的。此外，农场之间生物量的变化随着时间的推移而增加。当地观点表明，这是由技术分析和指导中无法可靠预测的突发外生和随机影响引起的。为应对这种持续存在的不确定性，当地观点强调需要在农场和村庄层面采用灵活和适应性的流程。这些发现在三个国家的一致性表明这些发现与类似的森林恢复干预措施有关。我们的研究结果为当地土地使用者的适应能力可以改善生态过程的社会生态途径提供了新的定量证据。我们的研究结果强调，森林恢复计划需要优先考虑对当地土地使用者能力的投资，并确保规则支持而不是阻碍适应性管理。