Filoso Solange, Bezerra Maíra Ometto, Weiss Katherine C B, Palmer Margaret A
Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, Maryland, United States of America.
National Socio-Environmental Synthesis Center, University of Maryland, Annapolis, Maryland, United States of America.
PLoS One. 2017 Aug 17;12(8):e0183210. doi: 10.1371/journal.pone.0183210. eCollection 2017.
Enhancing water provision services is a common target in forest restoration projects worldwide due to growing concerns over freshwater scarcity. However, whether or not forest cover expansion or restoration can improve water provision services is still unclear and highly disputed.
The goal of this review is to provide a balanced and impartial assessment of the impacts of forest restoration and forest cover expansion on water yields as informed by the scientific literature. Potential sources of bias on the results of papers published are also examined.
English, Spanish and Portuguese peer-review articles in Agricola, CAB Abstracts, ISI Web of Science, JSTOR, Google Scholar, and SciELO. Databases were searched through 2015.
Intervention terms included forest restoration, regeneration/regrowth, forest second-growth, forestation/afforestation, and forestry. Target terms included water yield/quantity, streamflow, discharge, channel runoff, and annual flow.
Articles were pre-selected based on key words in the title, abstract or text. Eligible articles addressed relevant interventions and targets and included quantitative information.
Most studies reported decreases in water yields following the intervention, while other hydrological benefits have been observed. However, relatively few studies focused specifically on forest restoration, especially with native species, and/or on projects done at large spatial or temporal scales. Information is especially limited for the humid tropics and subtropics.
While most studies reported a decrease in water yields, meta-analyses from a sub-set of studies suggest the potential influence of temporal and/or spatial scales on the outcomes of forest cover expansion or restoration projects. Given the many other benefits of forest restoration, improving our understanding of when and why forest restoration can lead to recovery of water yields is crucial to help improve positive outcomes and prevent unintended consequences. Our study identifies the critical types of studies and associated measurements needed.
由于对淡水稀缺的担忧日益增加，加强供水服务是全球森林恢复项目的一个共同目标。然而，森林覆盖面积的扩大或恢复是否能改善供水服务仍不明确，且存在很大争议。
本综述的目的是根据科学文献，对森林恢复和森林覆盖面积扩大对产水量的影响提供一个平衡和公正的评估。同时还研究了已发表论文结果中潜在的偏差来源。
来自Agricola、CAB文摘、科学网（ISI Web of Science）、JSTOR、谷歌学术和SciELO的英文、西班牙文和葡萄牙文同行评审文章。对数据库进行了截至2015年的检索。
干预词包括森林恢复、更新/再生、次生林、造林/绿化和林业。目标词包括产水量/数量、径流、流量、河道径流和年流量。
文章根据标题、摘要或正文中的关键词进行预筛选。符合条件的文章涉及相关干预措施和目标，并包含定量信息。
大多数研究报告称，干预后产水量下降，同时也观察到了其他水文效益。然而，专门针对森林恢复（尤其是使用本地物种）和/或在大空间或时间尺度上开展的项目的研究相对较少。对于湿润热带和亚热带地区，相关信息尤其有限。
虽然大多数研究报告产水量下降，但部分研究的荟萃分析表明，时间和/或空间尺度可能会对森林覆盖面积扩大或恢复项目的结果产生影响。鉴于森林恢复还有许多其他益处，加深我们对森林恢复何时以及为何能导致产水量恢复的理解，对于帮助改善积极成果和防止意外后果至关重要。我们的研究确定了所需的关键研究类型和相关测量方法。
