Nighttime patterns in and controls of ecosystem respiration across lakes

The respiration of organic matter to CO2 by autotrophic and heterotrophic organisms in aquatic systems is a critical ecosystem process that structures food web dynamics, is linked to ecosystem trophic state, and has implications for global biogeochemical cycles. Although diel variability in rates of ecosystem respiration (ER) has long been recognized, only a handful of studies have examined intra-diel patters, and none have evaluated patterns among multiple lakes spanning gradients in biological and physical characteristics. We capitalized on the Global Lakes Ecological Observatory Network (GLEON) of autonomous, high-frequency sensor data from 25 globally distributed lakes to investigate patters in nighttime respiration rates and explore the variables that might be driving patterns.