Fresh Air for the Mire-Breathing Hypothesis: Sphagnum Moss and Peat Structure Regulate the Response of CO2 Exchange to Altered Hydrology in a Northern Peatland Ecosystem

Authors

Ally O’Neill, Michigan Technological UniversityFollow
Colin Tucker, USDA Forest Service
Evan S. Kane, Michigan Technological UniversityFollow

Document Type

Article

Publication Date

10-14-2022

Department

College of Forest Resources and Environmental Science

Abstract

Sphagnum-dominated peatlands store more carbon than all of Earth’s forests, playing a large role in the balance of carbon dioxide. However, these carbon sinks face an uncertain future as the changing climate is likely to cause water stress, potentially reducing Sphagnum productivity and transitioning peatlands to carbon sources. A mesocosm experiment was performed on thirty-two peat cores collected from two peatland landforms: elevated mounds (hummocks) and lower, flat areas of the peatland (hollows). Both rainfall treatments and water tables were manipulated, and CO2 fluxes were measured. Other studies have observed peat subsiding and tracking the water table downward when experiencing water stress, thought to be a self-preservation technique termed ‘Mire-breathing’. However, we found that hummocks tended to compress inwards, rather than subsiding towards the lowered water table as significantly as hollows. Lower peat height was linearly associated with reduced gross primary production (GPP) in response to lowered water tables, indicating that peat subsidence did not significantly enhance the resistance of GPP to drought. Conversely, Sphagnum peat compression was found to stabilize GPP, indicating that this mechanism of resilience to drought may transmit across the landscape depending on which Sphagnum landform types are dominant. This study draws direct connections between Sphagnum traits and peatland hydrology and carbon cycling.

Publisher's Statement

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. Publisher’s version of record: https://doi.org/10.3390/w14203239

Publication Title

Water (Switzerland)

Recommended Citation

O’Neill, A., Tucker, C., & Kane, E. (2022). Fresh Air for the Mire-Breathing Hypothesis: Sphagnum Moss and Peat Structure Regulate the Response of CO2 Exchange to Altered Hydrology in a Northern Peatland Ecosystem. Water (Switzerland), 14(20). http://doi.org/10.3390/w14203239
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/16513

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

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