Skip to main content
Research article - Peer-reviewed, 2021

Cleaner air reveals growing influence of climate on dissolved organic carbon trends in northern headwaters

de Wit, Heleen A.; Stoddard, John L.; Monteith, Donald T.; Sample, James E.; Austnes, Kari; Couture, Suzanne; Folster, Jens; Higgins, Scott N.; Houle, Daniel; Hruska, Jakub; Kram, Pavel; Kopacek, Jiri; Paterson, Andrew M.; Valinia, Salar; Van Dam, Herman; Vuorenmaa, Jussi; Evans, Chris D.

Abstract

Surface water browning, the result of increasing concentrations of dissolved organic matter (DOM), has been widespread in northern ecosystems in recent decades. Here, we assess a database of 426 undisturbed headwater lakes and streams in Europe and North America for evidence of trends in DOM between 1990 and 2016. We describe contrasting changes in DOM trends in Europe (decelerating) and North America (accelerating), which are consistent with organic matter solubility responses to declines in sulfate deposition. While earlier trends (1990-2004) were almost entirely related to changes in atmospheric chemistry, climatic and chemical drivers were equally important in explaining recent DOM trends (2002-2016). We estimate that riverine DOM export from northern ecosystems increased by 27% during the study period. Increased summer precipitation strengthened upward dissolved organic carbon trends while warming apparently damped browning. Our results suggest strong but changing influences of air quality and climate on the terrestrial carbon cycle, and on the magnitude of carbon export from land to water.

Keywords

sulfate deposition; carbon cycle; precipitation; catchment DOC export; surface water browning; organic matter solubility

Published in

Environmental Research Letters
2021, volume: 16, number: 10, article number: 104009
Publisher: IOP PUBLISHING LTD

Authors' information

de Wit, Heleen A.
Norwegian Institute for Water Research (NIVA)
Stoddard, John L.
United States Environmental Protection Agency
Monteith, Donald T.
UK Centre for Ecology and Hydrology (UKCEH)
Sample, James E.
Norwegian Institute for Water Research (NIVA)
Austnes, Kari
Norwegian Institute for Water Research (NIVA)
Couture, Suzanne
Environment and Climate Change Canada
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Higgins, Scott N.
IISD Expt Lakes Area Inc
Houle, Daniel
Environment and Climate Change Canada
Hruska, Jakub
Czech Geological Survey
Kram, Pavel
Czech Geological Survey
Kopacek, Jiri
Czech Academy of Sciences
Paterson, Andrew M.
Ontario Ministry of the Environment, Conservation and Parks
Valinia, Salar
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Valinia, Salar
Norwegian Institute for Water Research (NIVA)
Van Dam, Herman
Consultancy Water and Nat
Vuorenmaa, Jussi
Finnish Environment Institute
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
UK Centre for Ecology and Hydrology (UKCEH)

UKÄ Subject classification

Environmental Sciences

Publication Identifiers

DOI: https://doi.org/10.1088/1748-9326/ac2526

URI (permanent link to this page)

https://res.slu.se/id/publ/113803