Exploring the Drivers Controlling the Priming Effect and Its Magnitude in Aquatic Systems
Lúcia Fernandes Sanches, Bertrand Guenet, Nicholas A. C. Marino, Francisco de Assis Esteves
Abstract
Abstract Changes in mineralization rates of stable or persistent organic matter induced by inputs of labile organic matter can alter the organic carbon (C) balance along the terrestrial‐aquatic ecosystem continuum. This phenomenon, also known as the priming effect, is well‐established in terrestrial ecosystems, but has only recently been explored in the domain of aquatic ecology–with widely contrasting responses of stable carbon to the priming effect reported across the literature. Here, we compiled data from experimental studies on C mineralization in aquatic systems that directly or indirectly tested for the priming effect and used a meta‐analytic approach to investigate the physical and chemical drivers behind the differing outcomes reported across studies. We found that the reported heterogeneity could be explained by two main factors: how the priming effect is measured and whether the study was performed in the laboratory or under field conditions. These findings suggest that how the priming effect is tested and measured has strong implications for its detection and magnitude.