Seasonal Net Ecosystem Carbon Exchange of a Regenerating Cutaway Bog: How Long Does it Take to Restore the C-Sequestration Function?

Authors

  • Emanuela Samaritani,

    Corresponding author
    1. WSL, Swiss Federal Institute for Forest, Snow, and Landscape Research, Ecosystem Boundaries Research Unit, Wetlands Research Group, Station 2, CH-1015 Lausanne, Switzerland
    2. Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Ecological Systems, Station 2, CH-1015 Lausanne, Switzerland
    3. Laboratory of Soil Biology, Institute of Biology, University of Neuchâtel, CH-2009 Neuchâtel, Switzerland
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  • Andy Siegenthaler,

    1. WSL, Swiss Federal Institute for Forest, Snow, and Landscape Research, Ecosystem Boundaries Research Unit, Wetlands Research Group, Station 2, CH-1015 Lausanne, Switzerland
    2. Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Ecological Systems, Station 2, CH-1015 Lausanne, Switzerland
    3. Laboratory of Soil Biology, Institute of Biology, University of Neuchâtel, CH-2009 Neuchâtel, Switzerland
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  • Mika Yli-Petäys,

    1. Department of Forest Ecology, University of Helsinki, PO Box 27, FIN-00014 Helsinki, Finland
    2. Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FIN-39700 Parkano, Finland
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  • Alexandre Buttler,

    1. Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Ecological Systems, Station 2, CH-1015 Lausanne, Switzerland
    2. WSL, Swiss Federal Institute for Forest, Snow, and Landscape Research, Community Ecology Research Unit, Restoration Ecology Research Group, Station 2, CH-1015 Lausanne, Switzerland
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  • Pascal-Antoine Christin,

    1. University of Lausanne, Department of Ecology and Evolution, Biophore, CH-1015 Lausanne, Switzerland
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  • Edward A. D. Mitchell

    1. WSL, Swiss Federal Institute for Forest, Snow, and Landscape Research, Ecosystem Boundaries Research Unit, Wetlands Research Group, Station 2, CH-1015 Lausanne, Switzerland
    2. Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Ecological Systems, Station 2, CH-1015 Lausanne, Switzerland
    3. Laboratory of Soil Biology, Institute of Biology, University of Neuchâtel, CH-2009 Neuchâtel, Switzerland
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E. Samaritani, email emanuela.samaritani@gmail.com

Abstract

We measured the net ecosystem exchange (NEE) and respiration rates and modeled the photosynthesis and respiration dynamics in a cutover bog in the Swiss Jura Mountains during one growing season at three stages of regeneration (29, 42, and 51 years after peat cutting; coded sites A, B, and C) to determine if reestablishment of Sphagnum suffices to restore the C-sequestration function. From the younger to the older stage Sphagnum cover increased, while net primary Sphagnum production over the growing season decreased (139, 82, and, 67 g m−2 y−1 for A, B, and C respectively), and fen plant species were replaced by bog species. According to our NEE estimations, over the vegetation period site A was a net CO2-C source emitting 40 g CO2-C/m2 while sites B and C were accumulating CO2-C, on average 222 and 209 g CO2-C/m2, respectively. These differences are due to the higher respiration in site A during the summer, suggesting that early regeneration stages may be more sensitive to a warmer climate. Methane fluxes increased from site A to C in parallel with Eriophorum vaginatum cover and vascular plant leaf area. Our results show that reestablishing a Sphagnum cover is not sufficient to restore a CO2-sequestrating function but that after circa 50 years the ecosystem may naturally regain this function over the growing season.

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