Integrating ecosystem metabolism and consumer allochthony reveals nonlinear drivers in lake organic matter processing

Abstract Lakes process both terrestrial and aquatic organic matter, the relative contribution from each source is often measured via ecosystem metabolism resource use in food web (i.e., consumer allochthony). Yet, allochthony are rarely considered together, despite possible interactions potential for them to respond same lake characteristics. In this study, we compiled global datasets of gross primary production (GPP), respiration (ER), zooplankton compare strength shape relationships with physicochemical characteristics across a broad set lakes. GPP was positively related total phosphorus (TP) lakes intermediate TP concentrations (11–75 μ g L −1 ) highest dissolved carbon (DOC) concentrations. While ER were strongly correlated, decoupling occurred at high DOC Lastly, had unimodal relationship variably DOC. By integrating allochthony, identified similar change points (4.5–10 mg (8–20 concentrations, indicating that may be coupled inversely related. The ratio DOC:nutrients also helped identify conditions where matter processing responded more autochthonous or allochthonous sources. As globally face eutrophication browning, predicting how will requires an updated paradigm incorporates nonlinear dynamics interactions.