Revisiting Odum (1956): A synthesis of aquatic ecosystem metabolism

H. T. Odum's influential Limnology and Oceanography 1956 publication compared gross primary production (GPP) and ecosystem respiration (ER) among aquatic ecosystems. Few syntheses of aquatic ecosystem metabolism have been completed since. We used Odum's conceptual framework to compare GPP and ER from open-water diel oxygen curves in lakes, wetlands, estuaries, and streams (n = 350). We also documented environmental drivers of metabolism among ecosystems. GPP and ER were strongly related in lakes and estuaries, but weakly related in streams and wetlands. GPP and ER were highest in estuaries, and GPP : ER was lowest in streams. Differences in the magnitude and variability of metabolism among ecosystems were attributable to landscape and water-column factors. Watershed size and phosphorus (P) concentrations were positively related to GPP and ER across all ecosystems. Considered independently, lake and estuary GPP were driven by P concentrations. In contrast, land-use and canopy cover drove stream metabolism, not nutrient concentrations. Results confirmed the classic paradigm that estuaries are the most productive aquatic ecosystem; however, our synthesis showed that relative to streams and estuaries, there was higher variation in lake GPP and ER than previously documented. Results will be valuable for management, restoration, and carbon budgets, which incorporate metabolism measurements at both the catchment and landscape scales. As metabolism datasets grow, future syntheses will address challenges including seasonality, sensor deployment time and location, hydrology, and variation in analytical conventions by discipline. Ongoing technological and computational advancements, combined with increased communication among subdisciplines, should also expand insights generated by subsequent metabolism syntheses.