How humans alter dissolved organic matter composition in freshwater
- Author(s)
- Marguerite A. Xenopoulos, Rebecca T. Barnes, Kyle S. Boodoo, David Butman, Núria Catalán, Sarah C. D’Amario, Christina Fasching, Dolly N. Kothawala, Oliva Pisani, Christopher T. Solomon, Robert G.M. Spencer, Clayton J. Williams, Henry F. Wilson
- Abstract
Dissolved organic matter (DOM) is recognized for its importance in freshwater ecosystems, but historical reliance on DOM quantity rather than indicators of DOM composition has led to an incomplete understanding of DOM and an underestimation of its role and importance in biogeochemical processes. A single sample of DOM can be composed of tens of thousands of distinct molecules. Each of these unique DOM molecules has their own chemical properties and reactivity or role in the environment. Human activities can modify DOM composition and recent research has uncovered distinct DOM pools laced with human markers and footprints. Here we review how land use change, climate change, nutrient pollution, browning, wildfires, and dams can change DOM composition which in turn will affect internal processing of freshwater DOM. We then describe how human-modified DOM can affect biogeochemical processes. Drought, wildfires, cultivated land use, eutrophication, climate change driven permafrost thaw, and other human stressors can shift the composition of DOM in freshwater ecosystems increasing the relative contribution of microbial-like and aliphatic components. In contrast, increases in precipitation may shift DOM towards more relatively humic-rich, allochthonous forms of DOM. These shifts in DOM pools will likely have highly contrasting effects on carbon outgassing and burial, nutrient cycles, ecosystem metabolism, metal toxicity, and the treatments needed to produce clean drinking water. A deeper understanding of the links between the chemical properties of DOM and biogeochemical dynamics can help to address important future environmental issues, such as the transfer of organic contaminants through food webs, alterations to nitrogen cycling, impacts on drinking water quality, and biogeochemical effects of global climate change.
- Organisation(s)
- Department of Geography and Regional Research
- External organisation(s)
- Università degli Studi di Trento, Colorado College, University of Washington, Université de Versailles-Saint-Quentin-en-Yvelines, Helmholtz-Zentrum für Umweltforschung, Uppsala University, USDA Agricultural Research Service, Cary Institute of Ecosystem Studies, Florida State University, Saint Michael's College, Brandon Research and Development Centre
- Journal
- Biogeochemistry: an international journal
- Volume
- 154
- Pages
- 323–348
- No. of pages
- 26
- ISSN
- 0168-2563
- DOI
- https://doi.org/10.1007/s10533-021-00753-3
- Publication date
- 2021
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 106002 Biochemistry, 105307 Water quality, 105308 Water resources, 207114 Water management
- Keywords
- ASJC Scopus subject areas
- Environmental Chemistry, Water Science and Technology, Earth-Surface Processes
- Sustainable Development Goals
- SDG 6 - Clean Water and Sanitation, SDG 13 - Climate Action, SDG 15 - Life on Land
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/ce017a75-2c13-4b9b-b5e0-d8c73a658668