Effect of multiple agricultural stressors on freshwater ecosystems: The role of community structure, trophic status, and biodiversity-functioning relationships on ecosystem responses

• Published in: The Science of the total environment Vol. 807; no. Pt 3; p. 151052
• Main Authors: Polazzo, Francesco, dos Anjos, Talles Bruno Oliveira, Arenas-Sánchez, Alba, Romo, Susana, Vighi, Marco, Rico, Andreu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.02.2022
• Subjects: Biodiversity; Ecosystem; Ecosystem functioning; Eutrophication; Fresh Water; Freshwater biodiversity; Multiple stressors; Pesticides; Multiple stressors; Ecosystem functioning; Freshwater biodiversity; Pesticides; Eutrophication
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.151052

The toxicity and widespread use of agricultural pesticides threaten freshwater biodiversity, but their long-term effects under different nutrient concentrations are poorly understood. We evaluated the single or combined effects of two pesticides (chlorpyrifos and diuron) under different nutrient regimes (mesotrophic and eutrophic) on community structure and ecosystem functions in replicated pond mesocosms. The individual application of nutrients and pesticides affected community composition and species richness. Ecosystem functioning was generally less sensitive to chemical stress than community structure, while eutrophication fostered the dominance of species that are more resilient to pesticides. Stressor interactions were significant at different time points, with late stressor interactions affecting the recovery of community composition. We also found that the correlation between biodiversity and relevant ecosystem functions, such as primary productivity and total ecosystem respiration, can be shifted from positive to negative under particular stress conditions. Our study demonstrates that nutrients enrichment is a key factor influencing the resilience of freshwater ecosystems to multiple stressors and that functional redundancy allows maintaining constant levels of functioning even under high toxic stress pressure. [Display omitted] •We tested the effects of multiple agricultural stressors on freshwater mesocosms.•Several stressors' interactions appeared only after 50 days from their application.•Nutrients promoted dominance of pesticide-resilient species.•Ecosystem function was less sensitive to stressor effects than community structure.•The biodiversity-ecosystem functioning correlation was shifted by some stressors.