Rewetting increases vegetation cover and net growing season carbon uptake under fen conditions after peat-extraction in Manitoba, Canada

• Published in: Scientific reports Vol. 13; no. 1; pp. 20588 - 13
• Main Authors: Turmel-Courchesne, Laurence, Davies, Marissa A., Guêné-Nanchen, Mélina, Strack, Maria, Rochefort, Line
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.11.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 704/158/854; 704/47/4113; Aquatic ecosystems; Aquatic plants; Canada; Carbon Dioxide; Carbon sequestration; Carbon sinks; Ecosystem; Emissions; Fens; Growing season; Humanities and Social Sciences; Manitoba; Methane; multidisciplinary; Peat; Peatlands; Plants; Propagules; Recovery of function; Science; Science (multidisciplinary); Seasons; Soil; Vegetation; Vegetation cover; Vegetation establishment; Vegetation surveys; Water; Water levels; Water management; Wetlands; Canada; Manitoba; Manitoba Canada
• DOI: 10.1038/s41598-023-47879-y
• ISSN: 2045-2322

The moss layer transfer technique has been developed to restore the carbon sequestration function and typical vegetation of Sphagnum -dominated peatlands after peat extraction in North America. However, the technique does not lead to successful bryophyte establishment when applied to peatlands with a richer residual fen peat. Therefore, we evaluated an alternative method of active rewetting and passive vegetation establishment using vegetation surveys and carbon dioxide and methane (CH 4 ) flux measurements at a post-extracted fen in southern Manitoba, Canada. After one growing season post-rewetting, wetland vegetation established and the site was a net carbon sink over the growing season. However, high abundance of Carex lasiocarpa 10 years post-treatment led to higher CH 4 emissions than the reference ecosystem. Successful establishment of wetland vegetation is attributed to the area being surrounded by undisturbed fens that can provide a local source of plant propagules. Bryophyte expansion was less successful than vascular plants, likely due to episodic flooding and shading from the sedge communities. Therefore, careful management of water levels to just below the peat surface is needed if reference vegetation community recovery is the goal of restoration. Water level management will also play a key role in controlling CH 4 emissions to maximize carbon sequestration potential.