A global surge in ‘artisanal’, smallscale mining (ASM) threatens biodiverse tropical forests and exposes residents to dangerous levels of mercury. In response, governments and development agencies are investing millions (USD) on ASM formalization; registering concessions and demarcating extraction zones to promote regulatory adherence and direct mining away from ecologically sensitive areas. The environmental outcomes of these initiatives are seldom systematically assessed. We examine patterns of mining-related deforestation associated with formalization efforts in a gold-rich region of the Peruvian Amazon. We track changes from 2001 to 2014 when agencies: (a) issued 1701 provisional titles and (b) tried to restrict mining to a >5000 km² ‘corridor’. We use fixed-effect regression models and matching methods to control for gold price, geology, and accessibility. Mining increased dramatically during this period, clearing ∼40 000 ha of forest. After the mining corridor was declared and enforcement increased, new mining sites were opened more frequently within titled areas and inside the corridor than elsewhere. However, mining also increased in protected area buffer zones and native communities, and the proportion of mining area occurring outside the corridor grew, concentrated in a few hotspots. Interviews (n = 47) revealed that the hoped-for regulatory adherence failed to materialize because miners who were issued provisional titles started operations without complying with attendant environmental rules. Overlapping land claims for agriculture and forest extraction proved a major obstacle for obtaining full legal rights to mine. Miners resented the slow, costly formalization process but many sought titles to bolster territorial claims, avoid policing, obtain credit and recruit paying ‘guest’ miners who generally ignored regulations. We find that responses to formalization varied with changing context and while formalization may curb mining in some circumstances, it may exacerbate it in others. Without adequate enforcement, interagency coordination, and attention to competing land claims, formalizing ASM may accelerate ecological destruction.

全球范围内“手工”小规模采矿 (ASM) 的激增威胁着生物多样性丰富的热带森林，并使居民暴露在危险水平的汞之下。作为回应，政府和发展机构正在为 ASM正规化投资数百万美元；登记特许权并划定开采区，以促进遵守法规并直接在生态敏感地区以外进行采矿。很少系统地评估这些举措的环境结果。我们研究了与秘鲁亚马逊金矿资源丰富的地区的正规化工作相关的与采矿相关的森林砍伐模式。我们跟踪了 2001 年到 2014 年的变化，当时机构：(a) 颁发了 1701 个临时所有权和 (b) 试图将采矿限制在 >5000 公里²'走廊'。我们使用固定效应回归模型和匹配方法来控制黄金价格、地质和可达性。在此期间，采矿业急剧增加，清除了约 40 000 公顷的森林。在宣布采矿走廊并加强执法后，与其他地方相比，在标题区域和走廊内开设新矿场的频率更高。然而，保护区缓冲区和土著社区的采矿业也有所增加，走廊外的采矿区比例有所增加，集中在少数热点地区。访谈 ( n= 47) 透露，由于获得临时所有权的矿工在不遵守相关环境规则的情况下开始运营，因此所希望的监管遵守未能实现。农业和森林采伐的重叠土地要求证明是获得完全合法的采矿权的主要障碍。矿工们对缓慢、成本高昂的正规化过程感到不满，但许多矿工寻求所有权以支持领土主张、避免监管、获得信贷和招募通常无视法规的付费“客座”矿工。我们发现对形式化的反应随着环境的变化而变化，虽然形式化在某些情况下可能会抑制挖矿，但在其他情况下可能会加剧挖矿。如果没有足够的执法、机构间协调和对相互竞争的土地要求的关注，ASM 的正规化可能会加速生态破坏。