Ecotourism is growing rapidly in biodiversity hotspots because of its promise to achieve both economic growth and environmental conservation. We reviewed the literature for empirical evidence that ecotourism protects forests. Our conclusions are at once both sobering and encouraging. Ecotourism, as it is typically practiced, leads to deforestation. However, when accompanied by conservation mechanisms (e.g. protected area, Payment for Ecosystem Services, monitoring/enforcement), ecotourism can protect forests. Ecotourism sometimes leads to forest regeneration in agrarian landscapes, but trade-offs, for example old-growth deforestation or water pollution, may occur. From a methodological perspective, we found a dearth (only 17) of articles that empirically analyzed ecotourism impacts on forests, and no studies that used counterfactual impact evaluation approaches. We conclude that there is an insufficient evidence base for inferring effects of ecotourism on forests, and we identify research priorities to build knowledge about how, when, and where to implement ecotourism.

由于生态旅游有望实现经济增长和环境保护，因此它在生物多样性热点地区发展迅速。我们回顾了有关生态旅游保护森林的经验证据的文献。我们的结论既令人振奋又令人鼓舞。生态旅游通常会导致森林砍伐。但是，在伴随着保护机制（例如保护区，生态系统服务付款，监测/执行）的情况下，生态旅游可以保护森林。生态旅游有时会导致农业景观的森林更新，但是可能会出现取舍，例如，旧的森林砍伐或水污染。从方法论的角度来看，我们发现缺乏（仅有17篇）文章以经验分析了生态旅游对森林的影响，而且没有使用反事实影响评估方法的研究。我们得出的结论是，没有足够的证据来推断生态旅游对森林的影响，并且我们确定了研究重点，以建立有关如何，何时以及在何处实施生态旅游的知识。