New BG Letter: Warming vs. browning: a dual mechanism behind net ecosystem production of shallow brown aquatic systems

26 October 2026

Warming and browning (increasing organic carbon) in aquatic systems both promote heterotrophy via distinct mechanisms: browning alone enhances bacterial production and alters stoichiometry, which suppresses primary production. Browning and warming combined shift aquatic ecosystems toward net heterotrophy. This mesocosm study provides mechanistic insight into interacting drivers of global change, with broad relevance for northern freshwaters undergoing increasing browning and warming.

Editorial statement: The study shows that warming and browning both promote heterotrophy in shallow boreal lakes, but through distinct pathways: browning enhances bacterial production and alters stoichiometry of major nutrients (C, N, P), while warming suppresses primary production. The authors consider not only changes in nutrient stoichiometry, but also their potential consequences for ecosystem productivity due to environmental changes. This research topic is timely and likely becomes increasingly important in the future due to climate change.

Contact: Aleksey Paltsev (aleksey.paltsev@umu.se) and Isolde Callisto Puts (Isolde.puts@umu.se)