Bennett Micah G, Schofield Kate A, Lee Sylvia S, Norton Susan B
National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave. NW (8623-P), Washington, DC 20460, USA.
Environ Evid. 2017;6(18):1-13. doi: 10.1186/s13750-017-0097-8.
Eutrophication of freshwater ecosystems resulting from nitrogen and phosphorus pollution is a major stressor across the globe. Despite recognition by scientists and stakeholders of the problems of nutrient pollution, rigorous synthesis of scientific evidence is still needed to inform nutrient-related management decisions, especially in streams and rivers. Nutrient stressor-response relationships are complicated by multiple interacting environmental factors, complex and indirect causal pathways involving diverse biotic assemblages and food web compartments, legacy (historic) nutrient sources such as agricultural sediments, and the naturally high spatiotemporal variabilityof lotic ecosystems. Determining nutrient levels at which ecosystems are affected is a critical first step for identifying, managing, and restoring aquatic resources impaired by eutrophication and maintaining currently unimpaired resources. The systematic review outlined in this protocol will compile and synthesize literature on the response of chlorophyll to nutrients in streams, providing a state-of-the-science body of evidence to assess nutrient impacts to one of the most widely-used measures of eutrophication. This review will address two questions: " a to and
Searches for published and unpublished articles (peer-reviewed and non-peer-reviewed) will be conducted using bibliographic databases and search engines. Searches will be supplemented with bibliography searches and requests for material from the scientific and management community. Articles will be screened for relevance at the title/abstract and full text levels using pre-determined inclusion criteria; 10% (minimum 50, maximum 200) of screened papers will be examined by multiple reviewers to ensure consistent application of criteria. Study risk of bias will be evaluated using a questionnaire developed from existing frameworks and tailored to the specific study types this review will encounter. Results will be synthesized using meta-analysis of correlation coefficients, as well as narrative and tabular summaries, and will focus on the shape, direction, strength, and variability of available nutrient-chlorophyll relationships. Sensitivity analysis and meta-regression will be used to evaluate potential effects of study quality and modifying factors on nutrient-chlorophyll relationships.
氮磷污染导致的淡水生态系统富营养化是全球范围内的一个主要压力源。尽管科学家和利益相关者已经认识到营养物质污染问题，但仍需要对科学证据进行严格的综合分析，以便为与营养物质相关的管理决策提供信息，特别是在溪流和河流方面。营养应激源 - 响应关系因多种相互作用的环境因素、涉及不同生物群落和食物网组成部分的复杂间接因果途径、农业沉积物等遗留（历史）营养源以及河流生态系统自然存在的高时空变异性而变得复杂。确定生态系统受到影响的营养水平是识别、管理和恢复因富营养化而受损的水生资源以及维持目前未受损资源的关键第一步。本方案中概述的系统评价将汇编和综合关于溪流中叶绿素对营养物质响应的文献，提供一个科学证据体系，以评估营养物质对富营养化最广泛使用的衡量指标之一的影响。本综述将解决两个问题：“a到和
将使用文献数据库和搜索引擎搜索已发表和未发表的文章（同行评审和非同行评审）。搜索将辅以参考文献搜索以及向科学和管理界索取资料的请求。将使用预先确定的纳入标准在标题/摘要和全文层面筛选文章的相关性；10%（最少50篇，最多200篇）经筛选的论文将由多名评审员进行审查，以确保标准的一致应用。将使用从现有框架开发并针对本综述将遇到的特定研究类型进行调整的问卷来评估研究的偏倚风险。结果将使用相关系数的荟萃分析以及叙述性和表格性总结进行综合，并将重点关注可用的营养物质 - 叶绿素关系的形状、方向、强度和变异性。将使用敏感性分析和元回归来评估研究质量和修正因素对营养物质 - 叶绿素关系的潜在影响。
