Journal article
Land cover and nutrient enrichment regulates low‐molecular weight dissolved organic matter turnover in freshwater ecosystems
Limnology and Oceanography, Vol.66(8), pp.2979-2987
2021
Abstract
Dissolved organic matter (DOM) is a complex mixture of carbon-containing compounds. The low-molecular weight (LMW) fraction constitutes thousands of different compounds and represents a substantial proportion of DOM in aquatic ecosystems. The turnover rates of this LMW DOM can be extremely high. Due to the challenges of measuring this pool at a molecular scale, comparatively little is known of the fate of LMW DOM compounds in lotic systems. This study addresses this knowledge gap, investigating the microbial processing of LMW DOM across 45 sites representing a range of physicochemical gradients and dominant land covers in the United Kingdom. Radioisotope tracers representing LMW dissolved organic carbon (DOC) (glucose), dissolved organic nitrogen (DON) (amino acid mixture), dissolved organic phosphorus (DOP) (glucose-6-phosphate), and soluble reactive phosphorus (SRP, measured as orthophosphate) were used to measure the microbial uptake of different DOM compounds in river waters. The amount of DOM biodegradation varied between different components (DON ≥ DOC > DOP), with the rate of turnover of all three increasing along a gradient of N and P enrichment across the range of sites. Conversely, the uptake of SRP decreased along this same gradient. This was ascribed to preferential utilization of DOP over SRP. Dominant land cover had a significant effect on DOM use as a resource, due to its control of nutrient enrichment within the catchments. We conclude that nutrient enrichment of river waters will lead to further DOM removal from the water column, increased microbial growth, and a decrease in stream oxygen saturation, exacerbating the effects of eutrophication in rivers.
Details
- Title
- Land cover and nutrient enrichment regulates low‐molecular weight dissolved organic matter turnover in freshwater ecosystems
- Authors/Creators
- F.L. Brailsford (Author/Creator) - Bangor UniversityH.C. Glanville (Author/Creator) - Bangor UniversityM.R. Marshall (Author/Creator) - Bangor UniversityC.A. Yates (Author/Creator) - University of BristolA.T. Owen (Author/Creator) - University of the West of EnglandP.N. Golyshin (Author/Creator) - Bangor UniversityP.J. Johnes (Author/Creator) - University of BristolD.L. Jones (Author/Creator)
- Publication Details
- Limnology and Oceanography, Vol.66(8), pp.2979-2987
- Publisher
- Wiley Periodicals LLC on behalf of Association for the Sciences of Limnology and Oceanography
- Identifiers
- 991005542330907891
- Copyright
- © 2021 The Authors
- Murdoch Affiliation
- Murdoch University; Centre for Sustainable Farming Systems
- Language
- English
- Resource Type
- Journal article
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Source: InCites
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- Collaboration types
- Domestic collaboration
- International collaboration
- Citation topics
- 3 Agriculture, Environment & Ecology
- 3.45 Soil Science
- 3.45.1049 Dissolved Organic Matter
- Web Of Science research areas
- Limnology
- Oceanography
- ESI research areas
- Environment/Ecology