Heterotrophic aquatic metabolism and sustained carbon dioxide emissions in a mineral-soil wetland restored with treated effluent.

Autor: Bogard MJ; Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada. Electronic address: matthew.bogard@uleth.ca., Gunawardana PVSL; Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada., Soued C; Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada., Kalyn Bogard HJ; Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada., Smits KM; Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada., Flanagan LB; Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2023 Aug 01; Vol. 884, pp. 163584. Date of Electronic Publication: 2023 Apr 26.
DOI: 10.1016/j.scitotenv.2023.163584
Abstrakt: Wetlands are economically valuable ecosystems, in part because they purify wastewater by retaining and processing nutrients, organic matter (OM), and other pollutants. While natural wetlands are highly productive and sequester large pools of carbon (C), it is unclear whether the C cycle of restored treatment wetlands is functionally consistent with natural systems. This knowledge gap limits our appreciation for the role that wetland restoration can play as a natural solution to climate change. Here, we quantified metabolic and C cycling patterns of a restored, multi-basin wetland (Frank Lake, Alberta, Canada) receiving municipal and beef processing plant effluents rich in nutrients and OM. We conducted metabolic measurements in all three basins using dissolved oxygen sensors deployed under ice and in open water. Extreme production and respiration indicated that effluent was largely mineralized and replaced with wetland OM in transit. The heterotrophic status of all basins aligned with a published mass budget demonstrating the aquatic habitat of the wetland was an OM sink under current drought conditions that lengthen effluent processing time. Floating chamber measurements in open water zones confirmed that the wetland was a source of CO 2 to the atmosphere. From input to outflow, sustained emissions led to declining pCO 2 and a decline in the ratio of dissolved inorganic to organic C. Over 30 years post-restoration, the open water habitats in Frank Lake remain heterotrophic and a net source of CO 2 , suggesting that the trajectory of aquatic C cycling may be distinct from wetlands restored with non-effluent water sources.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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