Synthesizing Effects of Total Nitrogen and Total Phosphorus on River and Stream Ecosystems: Systematic Review Update
Our team has been working to complete three systematic reviews of the scientific literature to provide a comprehensive synthesis of studies investigating how stream and river ecosystems (and specifically chlorophyll-a, diatom, and benthic macroinvertebrate endpoints) respond to total nitrogen and total phosphorus concentrations. After screening through thousands of potentially relevant articles, we have identified more than 300 articles that report relationships between these nutrients and endpoints. We have completed the initial data extraction from all articles (of more than 20 environmental variables and more than a dozen other context variables) and are completing the final stages of the review: checking data consistency by completing double-extraction of 25% of articles (by endpoint), contacting authors for missing relationships and data (for chl-a), and extracting data from article figures and tables to calculate relationships (for chl-a). When we have finalized the extracted data, we will investigate nutrient stressor-response relationships and thresholds from the dataset – focusing initially on chl-a.