Feng K. auteur aut IRD Du X. auteur aut IRD Tao K. auteur aut IRD Zhang Y. H. auteur aut IRD Wang Y. D. auteur aut IRD Yuan J. auteur aut IRD Eros T. auteur aut IRD Wang Q. D. auteur aut IRD Hugueny Bernard auteur aut IRD text journalArticle eng text/pdf born digital access Understanding the productivity-diversity relationship is central in ecology. While hypotheses exist for explaining positive and negative monotonic trends, they have never been combined into one model to account for hump-shaped patterns. Here, we propose a unified model integrating the more-individuals, biomass-driven competition and environmental filtering hypotheses. Analyzing fish communities along a eutrophication gradient, we reconstructed the observed hump-shaped curve between productivity and species richness. Two productivity-related variables explained richness: community size (positive effect) and zooplanktivorous fish biomass (negative effect). Zooplanktivores, overly favored by high productivity, likely competed with juvenile stages of other species for zooplankton, leading to species exclusions. This offers rare evidence for intensified species interactions along a productivity gradient in animal communities. Competition-driven loss thus precedes stress-induced losses (e.g., hypoxia), offering potential for early-warning protocols to monitor eutrophication. specialized biomass-driven competition hypothesis environmental filtering eutrophication functional traits juvenile bottleneck lakes more individuals hypothesis negative species associations species evenness Yangtze River CINE: YANGTSE COURS D'EAU 020 036 082 28 11 e70256 [11 p.] 2025 1461-023X https://www.documentation.ird.fr/hor/fdi:010095513 10.1111/ele.70256 1461-023X [F B010095513] https://www.documentation.ird.fr/hor/fdi:010095513 https://www.documentation.ird.fr/intranet/publi/2025-12/010095513.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2025-12-10 2025-12-10 fdi:010095513 fre