After our GMOS Train Project Meeting, I, Charlotte Haugk (ESR 8), stayed in Abisko at the Abisko Scientific Research Station (ANS) for another week. The original plan was for Ali (ESR7) to spend some of his secondment at Stockholm University (SU) learning soils sampling techniques but unfortunately, he fell sick and could only join later to work on some samples in the lab.

Together with guest researcher Lauren Thompson from the University of Alberta and Alyssa Azaroff, a post-doc in my group at SU, we carried out the field campaign. We spent the first 3 days in a peatland called Storflaket, just a few minutes driving away from the research station. We were fortunate to samples as part of an experimental set-up that has been started at Storflaket peatland in 2005 by Margareta Johansson (University of Lund), where snow fences have been erected (see Fig. 1) to catch the snow each winter and simulate an increase of winter precipitation. Now, we mainly cored and sampled for permafrost soil in order to determine parameters like total mercury (THg), Monomethylmercury (MeHg) and carbon and nitrogen content. Additionally, we took samples to determine microbial communities that are important for Hg methylation and water samples on those plots, that were left with a melt water pond on top of it.

Coring permafrost is hard work! We brought heavy equipment with us including steel pipes, a sledge hammer, a peat corer and knives. To sample the active layer on top, we use a knife to cut through the peat, which goes fairly quick. For the permafrost we need the heavy equipment. We then store the peat samples in zip bags.

We first completed all fieldwork and then spent the remaining time in the lab at ANS. The main task was to incubate the peat samples we took under an oxygen-free environment and spike them with enriched Hg isotope tracers to see how the long-term manipulation of snow cover would lead to changes in the active layer depth and influences the methylation of mercury. Then we would freeze them at different time points, to see the development of Hg methylation over time, which meant we had to work efficiently, to not wake up 10 times during the night to stop incubations. Which did not go exactly according to plan, but with the midnight sun high up in the sky, it wasn’t hard to stay awake.

We divided up tasks: I was at the glove bag at all times (Fig. 2), and Lauren and Alyssa assisted and helped me a lot with labelling and weighting samples and with carrying samples back and forth from the lab to the cooling room. Thank you, team!!

In September we will to the same plots at Storflaket again to get a seasonal picture of the climate scenario field experiment.