Abstract

Low‐order streams are suggested to dominate the atmospheric CO₂ source of all inland waters. Yet, many large‐scale stream estimates suffer from methods not designed for gas emission determination and rarely include other greenhouse gases such as CH₄. Here, we present a compilation of directly measured CO₂ and CH₄ concentration data from Swedish low‐order streams (> 1600 observations across > 500 streams) covering large climatological and land‐use gradients. These data were combined with an empirically derived gas transfer model and the characteristics of a ca. 400,000 km stream network covering the entire country. The total stream CO₂ and CH₄ emission corresponded to 2.7 Tg C yr⁻¹ (95% confidence interval: 2.0–3.7) of which the CH₄ accounted for 0.7% (0.02 Tg C yr⁻¹). The study highlights the importance of low‐order streams, as well as the critical need to better represent variability in emissions and stream areal extent to constrain future stream C emission estimates.

Keywords

low-order streams; inland waters; carbon dioxide; methane; emissions; Sweden

Published in

Limnology and Oceanography Letters
2018, volume: 3, number: 3, pages: 156 - 167
Publisher: Wiley-Blackwell

Authors' information