Skip to main content
ARS Home » Southeast Area » Tifton, Georgia » Southeast Watershed Research » Research » Publications at this Location » Publication #377352
Research Project: Enhancing Water Resources, Production Efficiency and Ecosystem Services in Gulf Atlantic Coastal Plain Agricultural Watersheds

Location: Southeast Watershed Research

Title: How humans alter dissolved organic matter composition in freshwaters: relevance for the Earth's biogeochemistry

Author
item XENOPOULOS, MARGUERITE - Trent University
item BARNES, REBECCA - Colorado College
item BOODOO, KYLE - University Of Vienna
item BUTNAM, DAVID - University Of Washington
item CATALAN, NURIA - Us Geological Survey (USGS)
item D'AMARIO, SARAH - Trent University
item FASCHING, CHRISTINA - Helmholtz Centre For Environmental Research
item KOTHAWALA, DOLLY - Uppsala University
item Pisani, Oliva
item SOLOMON, CHRISTOPHER - Cary Institute Of Ecosystem Studies
item SPENCER, ROBERT - Florida State University
item WILLIAMS, CLAYTON - St Michael'S College
item WILSON, HENRY - Brandon Research Center

Submitted to: Biogeochemistry
Publication Type: Review Article
Publication Acceptance Date: 1/3/2021
Publication Date: 1/25/2021
Citation: Xenopoulos, M.A., Barnes, R., Boodoo, K., Butnam, D., Catalan, N., D'Amario, S., Fasching, C., Kothawala, D., Pisani, O., Solomon, C.T., Spencer, R.G., Williams, C.J., Wilson, H.F. 2021. How humans alter dissolved organic matter composition in freshwaters: relevance for the Earth's biogeochemistry. Biogeochemistry. 154:323-348. https://doi.org/10.1007/s10533-021-00753-3.
DOI: https://doi.org/10.1007/s10533-021-00753-3

Interpretive Summary: Dissolved organic matter (DOM) contains large quantities of dissolved carbon and nitrogen, and is important in regulating many biogeochemical processes in freshwater ecosystems. The quality of DOM (composition and biological reactivity) is highly dependent on its sources and processing in a watershed. The sources of DOM to freshwater systems and the environmental conditions under which DOM processing occurs, have been significantly altered by human activities. In this review, we discuss the importance of incorporating human activities into studies of the global carbon cycle. We summarize and discuss the last 36 years of research pertaining to the relationships between DOM composition and various aspects of anthropogenic change. We provide insight on how using DOM composition proxies can assist in gaining a better mechanistic understanding of DOM source, processing, sinks, and ultimately, the global carbon cycle. In the future, this deeper understanding of the links between the chemical properties of DOM and biogeochemical dynamics can be used to understand and address important 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.

Technical Abstract: Dissolved organic matter (DOM) is recognized for its importance in freshwater ecosystems. Human activities modify DOM composition with possible biogeochemical consequences increasingly being identified, but not yet well understood. Human activities also modify the environment which in turn will affect internal processing of freshwater DOM. Historically, studies in aquatic biogeochemistry have focused on the quantity of DOM and relied on relatively few indicators of DOM composition, which led to an incomplete understanding of DOM chemistry and an underestimation of its role and importance in biogeochemical processes. A single sample of DOM is complex and can be composed of tens of thousands of distinct molecules. Each of these unique DOM molecules have their own chemical properties and reactivity or role in the environment. There is a growing opportunity to use advanced chemical techniques to study DOM composition and gain a better mechanistic understanding of DOM sources and its processing in the environment. DOM composition proxies vary between simple DOM signals such as specific UV absorptivity at 254nm (SUVA254) to more detailed biochemical diversity using ultrahigh resolution mass spectrometry, each providing unique insights into different aspects of carbon dynamics. In the future, this deeper understanding of the links between the chemical properties of DOM and biogeochemical dynamics can be used to understand and address important 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.