Sammanfattning

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.

Nyckelord

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

Publicerad i

Environmental Research Letters
2021, Volym: 16, nummer: 10, artikelnummer: 104009
Utgivare: IOP PUBLISHING LTD

SLU författare

• Fölster, Jens

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Valinia, Salar

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    
  • Norsk Institutt for Vannforskning (NIVA)

• Evans, Christopher

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    
  • UK Centre for Ecology and Hydrology (UKCEH)

UKÄ forskningsämne

Miljövetenskap


Publikationens identifierare

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

Permanent länk till denna sida (URI)

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