The metabolic regimes of lake ecosystems

This synthesis seeks to spark research on the metabolic regimes of lakes, ponds, and reservoirs. A metabolic regime is the generalized annual pattern of ecosystem metabolism—gross primary production and ecosystem respiration—that characterizes a set of ecosystems. Characterizing metabolic regimes has increased understanding of terrestrial, marine, and stream ecosystems, but has been underexplored for lakes, ponds, and reservoirs despite a growing abundance of metabolism data from these systems. We propose three hypotheses about lake metabolic regimes and how and why they vary around the world. We motivate these hypotheses by examining results from a literature review and a recent large compilation of lake metabolism data, and by using those results to inform a conceptual model built from existing theory. Finally, we introduce a new global repository of lake metabolism data to enable tests of these hypotheses and other advances in lake ecosystem science.