EGU24-18409, updated on 11 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

CO2 and CH4 exchanges between moist moss tundra and atmosphere on Kapp Linne, Svalbard

Anders Lindroth1, Norbert Pirk2, Ingibjörg Jonsdottir3, Christian Stiegler4, Leif Klemedtsson5, and Mats Nilsson6
Anders Lindroth et al.
  • 1Lund University, Department of Physical Geography and Ecosystems Analysis, Lund, Sweden (
  • 2Department of Geosciences, University of Oslo, Oslo, Norway
  • 3Life and Environmental Sciences, University of Iceland, Reykjavik, Iceland
  • 4National Institute of Water and Atmospheric Research, Wellington, New Zealand.
  • 5Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
  • 6Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden

We measured CO2 and CH4 fluxes using chambers and eddy covariance (only CO2) from a moist moss tundra in Svalbard. The average net ecosystem exchange (NEE) during the summer (9 June-31 August) was negative (sink) with -0.139±0.032 µmol m-2s-1 corresponding to -11.8 g C m-2 for the whole summer. The cumulated NEE over the whole growing season (day no. 160 to 284) was -2.5 g C m-2. The CH4 flux during the summer period showed a large spatial and temporal variability. The mean value of all 214 samples was 0.000511±0.000315 µmol m-2s-1 which corresponds to a growing season estimate of 0.04 to 0.16 g CH4 m-2. Thus, we find that this moss tundra ecosystem is closely in balance with the atmosphere during growing season when regarding exchanges of  CO2 and CH4. The sink of CO2 as well as the source of CH4 are small in comparison with other tundra ecosystems in high Arctic.

Air temperature, soil moisture and greenness index contributed significantly to explain the variation in ecosystem respiration (Reco) while active layer depth, soil moisture and greenness index were the variables that best explained CH4 emissions. Estimate of temperature sensitivity of Reco and gross primary productivity (GPP) showed that the sensitivity is slightly higher for GPP than for Reco in the interval 0 – 4.5 ºC, thereafter the difference is small up to about 6 ºC and then it began to raise rapidly for Reco. The consequence of this, for a small increase in air temperature of 1 degree (all other variables assumed unchanged) was that the respiration increased more than photosynthesis turning the small sink into a small source (4.5 gC m-2) during the growing season. Thus, we cannot rule out that the reason why the moss tundra is close to balance today is an effect of the warming that has already taken place in Svalbard.

How to cite: Lindroth, A., Pirk, N., Jonsdottir, I., Stiegler, C., Klemedtsson, L., and Nilsson, M.: CO2 and CH4 exchanges between moist moss tundra and atmosphere on Kapp Linne, Svalbard, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18409,, 2024.