EGU23-6367, updated on 10 Jan 2024
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Processes affecting lateral carbon fluxes from drained forested peatlands

Marjo Palviainen1, Mari Könönen2, Elina Peltomaa1, Jukka Pumpanen3, Anne Ojala2, Eliza Hasselquist4, Hjalmar Laudon4, Ivika Ostonen5, Florence Renou-Wilson6, Ain Kull5, Gert Veber5, Virginia Mosquera4, and Annamari Laurén1
Marjo Palviainen et al.
  • 1University of Helsinki, Department of Forest Sciences, Helsinki, Finland (
  • 2Natural Resources Institute Finland, Finland
  • 3Faculty of Science and Forestry, University of Eastern Finland, Kuopio, Finland
  • 4Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
  • 5Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
  • 6School of Biology and Environmental Science, University College Dublin, Dublin, Ireland

Lateral carbon (C) flux results from complex interplay of formation, transport and biodegradation of dissolved organic carbon (DOC), and is an important but rather scarcely studied component of the C balance in peatlands. Temperature and water table (WT) are the primary factors regulating peat CO2 emissions and the release of DOC. DOC dynamics in soil is complicated because the DOC storage is continuously increased by the decomposition of solid organic matter, but simultaneously decreased by biodegradation. Any upscaling of lateral C fluxes requires understanding these coinciding processes. We studied the effect of temperature and WT on CO2 emission and DOC concentration in pore water while incubating peat columns (diameter 0.2 m height 0.5 m) in laboratory conditions for eight months. Peat columns were extracted from drained forested peatlands in Finland, Estonia, Sweden and Ireland. WT was set to -0.2 m and -0.4 m distance from the column upper end. During the incubation, the temperature ranged between 18  and 34 ⁰C. DOC samples were extracted in monthly intervals from the columns using Rhizon soil water samplers. At the same time CO2 emission was measured from the headspace of the column. DOC biodegradation to CO2 and its temperature sensitivity was studied by incubating soil water samples in controlled conditions. The quality (aromaticity) of DOC was investigated with a UV-VIS spectrophotometer. The effect of temperature on DOC concentration was not straightforward unlike in the case of CO2 emission. DOC concentration increased steepest when the temperature exceeded 25  ⁰C, whereas with lower temperatures DOC was unchanged or slightly decreased. This can be due to different temperature sensitivities of DOC release and its biodegradation. Low WT resulted in high CO2 emissions and DOC concentrations. These results are important in developing ecosystem models accounting for lateral C fluxes and the effects of forest management, drainage and climate change in managed peatlands.

How to cite: Palviainen, M., Könönen, M., Peltomaa, E., Pumpanen, J., Ojala, A., Hasselquist, E., Laudon, H., Ostonen, I., Renou-Wilson, F., Kull, A., Veber, G., Mosquera, V., and Laurén, A.: Processes affecting lateral carbon fluxes from drained forested peatlands, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6367,, 2023.