CENPERM Annual Report 2015

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Highlights 2015 Highlights of 2015 include intensive field work at 6 sites in Greenland and new snow fences being built and instrumented in South Greenland. It has also been a productive year in terms of scientific papers. The following four papers published in 2015 highlight two issues: that ecosystems across the ice-free Greenland are highly climate sensitive, and secondly that changes in ecosystem functioning should be considered over both short and long time scales. 1. Decomposition of organic carbon from thawing permafrost soils is considered a potentially critical global-scale feedback on climate change. The accompanying heat production from the microbial metabolism has been recognized as a potential positive feedback mechanism to enhance permafrost thawing and the release of soil carbon. This internal heat production is poorly understood but now Hollesen et al. (2015c) reported in Nature Climate Change that permafrost thawing in organic arctic soils can be accelerated by ground heat production. We quantified the variability of heat production in different types of organic permafrost soils across Greenland and documented that these soils produce enough heat to increase soil temperatures and accelerate the decomposition processes. We demonstrated that the impact of climate changes on organic soils could be enhanced compared to other soil types with crucial implications for the amounts of organic matter being decomposed and potentially emitted as greenhouse gases. We also showed that degradation of the uniquely well-preserved, organic archaeological artefacts in kitchen middens may be accelerated by internal heat production, with the risk of losing evidence of human activity in the Arctic. 2. Growing-season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effect of winter warming and 6 CENPERM Annual Report 2015 snow remains an open question. Hollesen et al. (2015a) reported in Global Change Biology that winter warming may have been an important co-driver for dwarf birch (Betula nana) growth in West Greenland during the past century. We presented a more than 100-year-long Betula nana ring-width chronology from the Disko Island that demonstrated a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth was especially pronounced during the periods from 19101930 and 1990 2011 that were dominated by significant winter warming. In order to explain the strong winter impact on growth, we assessed the importance of different environmental factors by using site specific measurements from 1991-2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results showed a strong positive growth response to the amount of thawing and growing degree days as well as to winter and spring soil temperatures. These findings help to explain the recently observed greening of the Arctic, which may further accelerate in future years due to both direct and indirect effects of winter warming. 3. The arctic climate is projected to change and expected to alter litter decomposition rates, which in turn could affect carbon and nitrogen (N) cycling rates in tundra ecosystems. However, little is known of seasonal climate change effects on plant litter decomposition rates and N dynamics. Based on the CENPERM snow fence experimental site on Disko Island, Blok et al. (2015a) tested the effects of snow addition, warming and shrub removal on mass loss and N dynamics of two shrub tissue types with contrasting quality. Field incubations of litter bags started in late fall and were harvested sequentially to study seasonal changes. We observed a significant positive effect of deeper snow on ANNUAL REPORT 2015 CENPERM Center for Permafrost Field sites Brønlundhus Svalbard Longyearbyen Greenland Zackenberg Disko Qajaa Sweden Kangerlussuaq Nuuk Narsarsuaq Abisko Sermilik Directors welcome The vision of Center for Permafrost Highlights 2015 Højdepunk ter 2015 Breaking the silence of tundra sur faces Publications & conferences Communication & outreach Educational activities Ongoing research projects & graduate students International collaborators & funding CENPERM sta 2 CENPERM Annual Report 2015 Directors welcome CENPERM has ended its fourth year thanks to the Danish National Research Foundation. In 2015, a new snow fence experiment was established near Narsarsuaq in South Greenland. These additional snow fences will be used for exploring summer and winter warming effects on soil-plant inte The vision of Center for Permafrost Microbial activity Plant ecology CENPERM Permafrost soil & landscape dynamics CENPERM integrates multidisciplinary research of biogeochemical and physical processes in a climate-vegetation-soil-microorganismpermafrost approach in transects across the major cli Photo: Bo Elberling CENPERM Annual Report 2015 5 Highlights 2015 Highlights of 2015 include intensive field work at 6 sites in Greenland and new snow fences being built and instrumented in South Greenland. It has also been a productive year in terms of scientific papers. The following four papers published in 2015 highlight two issues: that ecosys winter mass loss, which was considered a result of observed higher soil winter temperatures and corresponding increased winter microbial litter decomposition in deep snow plots. In contrast, warming reduced litter mass loss during spring, possibly because the dry spring conditions might have dried o Højdepunkter 2015 Højdepunkterne i 2015 omfatter intensivt feltarbejde ved 6 lokaliteter i Grønland samt opsætning og instrumentering af nye snehegn i Sydgrønland. Det har også været et produktivt år i forhold til videnskabelige artikler. De følgende 4 artikler er udgivet i 2015 og fremhæver 2 emner rester i felter med dyb sne. I modsætning hertil resulterede opvarmning i et reduceret massetab af planterester om foråret, sandsynligvis fordi de tørre forhold om foråret kan have udtørret jordens øverste lag af dødt plantemateriale (litterlaget) og derved begrænset den mikrobielle omsætning. Resul Breaking the silence of tundra surfaces by Andreas Westergaard-Nielsen, Assistant Professor, CENPERM, University of Copenhagen Image data of the Earth surface from above is a strong tool for evaluating the magnitude of certain ecosystem traits. Data collected from air- and spaceborne platforms can To overcome some of the limitations in the satellite data, a multidisciplinary CENPERM team started a detailed mapping in August 2015. The area of interest is covering a 5-km transect in proximity to Blæsedalen on Disko Island, representing a variety of elevations and land cover classes from dry abr Publications & conferences Blok, D., Elberling, B., Michelsen, A. (2015a). Initial stages of tundra shrub litter decomposition may be accelerated by deeper winter snow but slowed down by spring warming. Ecosystems 19, online Oct. 17. Blok, D., Weijers, S., Welker, J., Cooper, E., Michelsen, A., Löff landscape significance. Journal of Geophysical Research: Biogeosciences 120, online Nov. 23. methane source. Nature Climate Change 5, 67-70. Jørgensen, C.J., Johansen, K.M.L., Westergaard-Nielsen, A., Elberling, B. (2015). Net regional methane sink in High Arctic soils of northeast Greenland. Natu Stibal, M., Gözdereliler, E., Cameron, K.A., Box, J.E., Stevens, I.T., Gokul, J.K., Schostag, M., Zarsky, J.D., Edwards, A., Irvine-Fynn, T.D.L., Jacobsen, C.S. (2015). Microbial abundance in surface ice on the Greenland Ice Sheet. Frontiers in Microbiology 6, 225. Stibal, M., Schostag, M., Cameron, Poster presentations at conferences, symposia, seminars etc. litter decomposition rates. Perth III: Mountains of Our Future, Perth, UK. Oct. 4-8. Albers, C.N., Johnsen, A.R., Jacobsen, O.S. (2015). Chloroform formation in Arctic and Subarctic soils - mechanism and emissions to the atmosphere. EGU Blok, D., Faucherre, S., Banyasz, I., Michelsen, A., Elberling, B. (2015). Legacy Effects of Warming on Permafrost Carbon Release. AGU Annual Fall Meeting, San Fransisco, USA , Dec. 14-18. Cameron, K.A, Stibal, M., Zarsky, J.D., Gözdereliler, E., Schostag, M., Jacobsen, C.S. (2015). Microbial commun Phillips, C.A., Wurzburger, N. (2015). Biogeochemical consequences of arctic shrub expansion. Ecosystems and Climate Change Mitigation, London, UK, Nov. 2-3. Phillips, C.A., Wurzburger, N. (2015). Biogeochemical consequences of shrub expansion. British Ecological Society, Edinburgh, UK, Dec. 13-16. Communication & outreach Climate changes, greenhouse gas emissions and the role of Arctic have again in 2015 been on the general agenda not the least due to United Nations Climate Change Conference (COP 21) in Paris by the end of the year. In the months prior to the conference, we experienced at CE Elberling, B. (2015). Kæmpe huller opdaget i Sibirien, Berlingske Tidende, Kids News (www. KIDSNEWS.06.05.2015), Mar. 6. Elberling, B. (2015). Kalaallit Nunaanni savaateqarneq: Ullumikkut siunissamilu / Fårehold i Grønland: Nu og i fremtiden (in Danish and Greenlandic), Sermitsiaq, 6, 32-33. Elberli Jan. 16. Meeting on Microbiology in Permafrost. Danmarks Mikrobiologiske Selskab. Speakers: Dirk Wagner, Lise Overås, Janine Goerths, Morten Schostag, Toke Andreasen. Feb. 5. Toke Thomas Høye, Jens Christian Skou Fellow Aarhus Institute of Advanced Studies: Arctic biodiversity and climate change lo Oct. 22. Verner Brandbyge Ernstsen, Associate Professor, IGN/CENPERM: Mapping and investigating landforms and landscapes in land-water transition zones. Oct. 29. Stef Weijers, Department of Geography, University of Bonn: Dendroecology of the Arctic. Nov. 12. Morten Schostag, PhD student, CENPERM/BIO Educational activities CENPERMs activities in 2015 have included a number of educational efforts. These include both arctic field courses and classic university courses at the basic and advanced levels at the University of Copenhagen. This includes developing a new course on how to use drones and sc Samfundsmæssigt væsentlige stofstrømme, Dept. of Geosciences and Natural Resource Management, University of Copenhagen, C. S. Nielsen. Teaching at the M.Sc. level Advanced bacteriology 2, Dept. of Biology, University of Copenhagen, autumn, A. Priemé. Arctic biology, Dept. of Biology, University of Ongoing research projects & graduate students In 2015 two WriteCamps were held off campus for PhD students and postdocs together with their supervisors. This turned out to be extremely fruitful for both publications and the social life of the group. Like the previous years a special Master theses wo PhD students, fully or partially funded by CENPERM 18 ongoing PhD projects, including 3 defended and 1 terminated PhD theses in 2015. Bendixen, Mette: Coastal morphodynamics in permafrost-affected areas in Greenland, Aug. 2012 - . Supervisors: Aart Kroon and Bo Elberling. Cable (Härtel), Stefanie: T Nielsen, Cecilie Skov: Arctic carbon and nitrogen cycling with a focus on CH4 fluxes: Interactive effects of temperature, soil moisture and gas transport pathways, Jan. 2013 - . Supervisors: Bo Elberling and Anders Michelsen. Schostag (Nielsen), Morten Dencker: Cryobiology of permafrost bacteria and Busch-Sørensen, Pernille: Impacts of warming, fertilization and shading on the emissions of the volatile organic compound isopren, and CO2 fluxes from vegetation and soil in a subarctic tundra ecosystem, Jun. 2014 - . Supervisor: Riikka Rinnan. Cable, William: The role of environmental factors in lo Rasmussen, Kerstin Elise Krøier: Modelling daily ground surface temperatures under changing snowpacks in Zackenberg and Qeqertarsuaq, Greenland. Completed Nov. 2015. Supervisor: Birger Ulf Hansen Rasmussen, Laura Helene: Thermal properties for simulating consequences of changes in thermal regime of Photo: Leif Bolding CENPERM Annual Report 2015 29 International collaborators & funding Research activities at CENPERM are linked to a number of well-established international arctic networks. These cooperation agreements are supplemented by a strong affiliation to internationally recognized researchers. External experts and Center evaluation Edwa International research partners and co-operators Adam Mickiewicz University, Poznan, Poland: Agata Buchwal. Alfred-Wegener-Institute (AWI), Potsdam, Germany: Permafrost modelling; AWI (Bremen) Marine sedimentation. Agriculture and Agri-Food, Ottawa, Canada: Shared fieldwork, North Greenland: Ed Greg University of Edinburgh, School of GeoSciences, UK: Isla Myers-Smith, Sandra Angers-Blondin. Pan-arctic shrub growth meta-analysis. University of Innsbruck, Institute of Ecology, Austria: Molecular analysis of glacial samples. University of Lund, Sweden. Paul A. Miller. Earth System Model University Danish National Research Foundation/NSF Graduate Research Opportunities Worldwide (GROW): Carbon Storage Consequences of Shrub Expansion: Exploring Plant Soil Relationships in a Changing Arctic Ecosystem. Grant holder: Bo Elberling/Anders Michelsen/Carly Phillips. Period: 2015-2016. DKK 241,920. Da CENPERM staff Researchers Albers Christian Nyrop Researcher Ambus Per Professor Andersen Thorbjørn J. Professor Christensen Anne T. Research assistant Elberling Bo Professor, Director Ernstsen Verner Brandbyge Associate professor Friborg Thomas Associate professor Hansen Birger CENPERM staff Karami Mojtaba PhD student Kramshøj, Magnus PhD student Lindwall Frida PhD student Markussen Thor N. PhD student McConnell Alistair PhD student Nielsen Cecilie Skov PhD student Ravn Nynne R. (Larsen) PhD student Schollert Michelle PhD student Schostag Mor ANNUAL REPORT 2015 The Danish National Research Foundation (DNRF) is an independent organization established by the Danish Parliament in 1991 with the objective to promote and stimulate basic research at the highest international level at the frontiers of all scientific fields. The Center of Excell