Højdepunkter
2020
Højdepunkter 2020 er dedikeret til vores
ph.d.-studerende ved CENPERM. På trods
udfordringerne som følge af Covid-19 restriktionerne, har de ph.d.-studerende bevaret
motivationen på et højt niveau, fortsat deres
forskning, afsluttet diverse delprojekter, og
nogle har måtte forsvaret deres afhandlinger
online. Tre tværfaglige videnskabelige artikler,
der hver er tilknyttet et ph.d.-projekter, fremhæves her. Artiklerne integrerer aspekter fra
både bio- og geovidenskab og viser, at vi fortsat
bliver overrasket over hvor komplekst Arktis
reagerer på nutidige klimaforandringer både i
forsøg og under naturlige forhold.
1. Jordvandskemi er en vigtig del af jordmiljøet
for at forstå klima-feedbackmekanismer koblet til
plantevækst, mikrobiel omsætning og nettoemissionen af drivhusgas. I en artikel i Soil Biology and
Biochemistry undersøgte Rasmussen et al. (2020)
jordvandskemien i en lavarktisk tundrahede og
et kærområde i Grønland. Forsøgsområderne
har været manipuleret på 3 måder og dertilhørende kombinationer: sommeropvarmning i
form af åbne klimakamre, ekstra sne i form af
snehegn, (der øger jordtemperaturen i slutningen af vinteren), og fjernelse af småbuske (for
at simulerer angreb fra planteædere). Der blev
foretaget målinger i perioden 20132016, hvor
der var stor variation i vejret fra år til år. Koncentrationen af næringsstoffer på tundraheden
faldt i løbet af hver vækstsæsonen og steg igen
om efteråret samtidig med løvfald. I kærområdet
var der modsat højest indhold af næringsstoffer
i vækstsæsonen. Sommeropvarmning på heden
ændrede ikke tilgængeligheden af næringsstoffer,
dog forekom der ændringer i visse næringsstoffer - såsom nitrat - i forbindelse med fjernelse af
buske eller ved ekstra sne. Dette understreger
kompleksiteten i økosystemers reaktion på en
eller flere klimapåvirkninger. Undersøgelsen viser
8
CENPERM Annual Report 2020
også, hvordan jordvandskemien varierer mellem
forskellige vegetationstyper, og at den fysiske
indvirkning på næringskredsløb er overraskende
begrænset, når man sammenligner flere år med
forskellige snemængder. Det er derfor vigtigt,
fortsat at kombinere undersøgelser for flere
år og fra flere vegetationstyper for at forstå og
forudsige, hvordan et arktisk landskab vil reagere
på fremtidige klimændringer.
2. Hvor permafrost tør kan der frigives både
CO2 og plantenæringsstoffer ved nedbrydning
af organisk stof. Det er et åbent spørgsmål, om
planter kan udnytte denne ekstra næringsstoffer og derved vokse og optage mere CO2 fra
atmosfæren. Pedersen et al. (2020) viser i en
artikel i Global Change Biology, at planter kan
optage kvælstof (N), som er frigivet under
rodzonen knyttet til en øget nedbrydning samt
kvælstof frigivet ved optøning ved grænsen til
permafrosten. Planteoptagelse af kvælstof blev
målt umiddelbart efter N-frigivelse (efterår) og
efter et år. Resultaterne viser, at arktiske planter
aktivt udnytter denne ekstra pulje af kvælstof
også sent i vækstsæsonen. Alle undersøgte
plantearter kunne optage N fra tøet permafrost
ned til cirka 1 meters dybde. Nogle plantearter
(Carex rupestris, Dryas octopetala, Kobresia
myosuroides) var bedre til at udnytte den
mere overfladenære pulje af kvælstof, mens
fx busken Salix arctica var bedre til at udnytte
kvælstof frigivet fra dybere jordlag. Dette viser
vigtigheden af permafrost-frigivet N som en ny
næringsstofkilde for arktiske planter. Vi konkluderer, at optøende permafrost kan frigive CO2
fra opbevaret organisk stof, men også kickstarte
en positiv feedback-mekanisme ved at gøre
næringsstoffer tilgængelige for nogle planter, så
de har bedre vækstbetingelser og efterfølgende
kan reducere økosystemets kulstofstab knyttet
til permafrost, der tør ved en øget plantevækst
over jorden.
ANNUAL REPORT 2020 CENPERM Center for Permafrost
Field sites Brønlundhus Qaanaaq Svalbard Longyearbyen Greenland Zackenberg Disko Qajaa Sweden Kangerlussuaq Nuuk Narsarsuaq Abisko Sermilik
Directors welcome Visions and aims Highlights 2020 Højdepunk ter 2020 Arctic wildf ires a burning hot topic Publications & conferences Communication & outreach Educational activities Ongoing research projects & graduate students International collaborators & funding CENPERM staff 3 4 6 8 10 12 16
2 CENPERM Annual Report 2020
Directors welcome The year 2020 has been a special year in many ways; a year with changes for almost everyone and difficult in different ways for most due to Covid-19. We have been able to complete most of the planned field work by continuously making changes according to regulations. Unfortunately,
Visions and aims 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 c
CENPERM Annual Report 2020 5
Highlights 2020 Highlights 2020 is dedicated to the PhDstudents of CENPERM. The students, despite Covid-19 and continued difficulties, have kept their motivation levels high and been able to continue their research, working intensively on specific projects, and for some defended online. Three multid
present the first Arctic multi-threat assessment focusing on the Nuuk region of Greenland. In this region, more than 300 archaeological sites are already threatened by exposure to impacts from microbial degradation, permafrost thaw, vegetation growth and erosion driven by climate change. Within the
Højdepunkter 2020 Højdepunkter 2020 er dedikeret til vores ph.d.-studerende ved CENPERM. På trods udfordringerne som følge af Covid-19 restriktionerne, har de ph.d.-studerende bevaret motivationen på et højt niveau, fortsat deres forskning, afsluttet diverse delprojekter, og nogle har måtte forsvare
3. Klimaforandringer truer de velbevarede arkæologiske områder i Arktis. I Archaeometry præsenterer Fenger-Nielsen et al. (2020) det første forsøg på i en arktisk sammenhæng, at sammenholde de mange trusler i en samlet trusselvurdering med fokus på Nuuk-regionen i Grønland. I denne region er der mer
Arctic wildfires a burning hot topic by Lena Hermesdorf, PhD Student, CENPER M, University of Copenhagen In recent years, wildfires in arctic tundra landscapes have increased in frequency, and models project them to increase in the future due to warmer and drier summers. To date, little is known a
In order to analyse whether the fire and destruction of vegetation led to changes in soil processes, and hence in GHG fluxes, we measured the exchange rates of all three GHGs and took several soil samples during three growing seasons (2017-2019). In this way we can differentiate between effects that
Publications & conferences International journals Andersen, E. A. S., Michelsen, A., Fenger-Nielsen, R., Hollesen, J., Ambus, P. L., Elberling, B. (2020). Nitrogen isotopes reveal high N retention in plants and soil of old Norse and Inuit deposits along a wet-dry arctic fjord transect in Greenland.
birch forest via effects on soil thermal regime and sequestration of deposited nitrogen. Journal of Ecology 13567. Kristensen, J. A., Michelsen, A., Metcalfe, D. B. (2020). Background insect herbivory increases with local elevation but makes minor contribution to element cycling along natural gradie
Rasmussen, L. H., Michelsen, A., LadegaardPedersen, P., Nielsen, C. S., Elberling, B. (2020). Arctic soil water chemistry in dry and wet tundra subject to snow addition, summer warming and herbivory simulation. Soil Biology and Biochemistry 141, 107676. Ravn, N. R., Elberling, B., Michelsen, A. (202
Westergaard-Nielsen, A., Balstrøm, T., Treier, U., Normand, S., Elberling, B. (2020). Estimating meltwater retention and associated nitrate redistribution during snowmelt in an Arctic tundra landscape. Environmental Research Letters 15, 034025. Wester-Larsen, L., Kramshøj, M., Albers, C. N., Rinnan,
Communication & outreach CENPERM continued its series of regular talks in spite of the Covid-19 situation; however, most talks during the year have been via zoom. By meeting regularly, it was possible to keep in touch and share problems and solutions within the Center. Unfortunately, a planned write
Elberling, B.: Four Citizen Science talks onboard Antarctic Cruise: Climate and environmental changes: trends and variations, Penguin colonies: a hotspot for greenhouse gas emissions, Dry Valleys: the cold desert but surprisingly alive, The Antarctic continent in a global context. Jan. Talks Elber
Jun. 11. Emily Pickering Pedersen. PhD student, CENPERN, BIO. Foraging deeply: Depth-specific plant nitrogen uptake in a high arctic permafrost ecosystem. Sep. 3. Welcome back from the field. Short reports on fieldwork. Sep. 17. Jesper Riis Christiansen, IGN/ Christian Juncher Jørgensen, AU. Methane
Educational activities CENPERMs activities in 2020 include a number of educational efforts, which this year mainly classic university courses at the basic and advanced levels at the University of Copenhagen. In addition to course taught, a number of M.Sc. meant theses have been supervised (see: Ongo
Climate change and biogeochemical cycles. Dept. of Biology, University of Copenhagen, autumn, R. Rinnan, K. Rousk, P. Ambus, G. Schurgers. Climate change - an interdisciplinary challenge. Dept. of Geosciences and Natural Resource Management, University of Copenhagen, autumn, R. Rinnan, G. Schurgers,
Ongoing research projects & graduate students Postdoc and Assistant Professor projects Alvarenga, Danillo: Interactions between cyanobacteria and moss-hosts. DImperio, Ludovica. Postdoc: Soil-plant interactions and greenhouse gas dynamics in permafrost-affected ecosystems. Kramshøj, Magnus. Postdoc
Defended PhD thesis 2020 Fenger-Nielsen, Rasmus: Archaeological sites threatened by climate change: a regional perspective from Greenland. Supervisors: Bo Elberling, Jørgen Hollesen and Aart Kroon. Defended: May 2020. Ongoing PhD projects 2020 Baggesen, Nanna: Emissions of biogenic volatile organ
Xu, Wenyi: Fire in Arctic tundra - impacts on bio-geochemical cycles. Supervisor: Per Ambus. Yun, Hanbo: Quantifying and modelling methane dynamics in contrasting landscapes of the Qinghai-Tibetan Plateau. Supervisor: Bo Elberling, co-supervisor: Ludovica D Imperio and Wenxin Zhang. Zastruzny, Sebas
Ongoing M.Sc. projects: 7 Christensen, Maj Paornak Sofie: The effects of enhanced precipitation and phosphorus addition on carbon dioxide and methane fluxes in heath tundra in Greenland. Supervisor: Anders Michelsen. Jacobsen, Cathrine Kallestrup: Plant ecophysiology, carbon cycling and vegetation
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. CENPERM has continuously extended the intern
Los Alamos National Laboratory, USA: C. Andresen, permafrost impacts on hydrology. Michigan State University, USA: Tiedje J.; microbial studies, scientific publications. The Netherlands Central Organisation for Radioactive Waste (COVRA). NOAA (National Oceanic and Atmospheric Administration) Global
University of Bergen, Norway: L. Øverås. University of Boulder, Institute for Arctic and Alpine Research (INSTAAR), Colorado, USA: I. Overeem, K. Barnhart. Coastal changes in Greenland. University of Eastern Finland, Department of Environmental Science, Finland: M. Kivimäenpää. Sample treatment, lig
Danish Ministry for Research: Integrated Carbon Observation System, Research Infrastructure (ICOS-RI). Grant holder: Thomas Friborg (2016-2021): 6.5 mio. Independent Research Fund Denmark, Sapere Aude DFF-Research leader: Climatic, ecological and molecular controls of nitrogen fixation in pristine s
CENPERM staff Researchers Ambus Per Lennart Professor Andersen Thorbjørn J. Professor Christiansen Casper Tai Postdoc Elberling Bo Professor, Director Friborg Thomas Associate professor Hansen Birger Ulf Associate professor Hollesen Jørgen Senior Researcher Kroon Aart Associat
CENPERM staff PhD students Baggesen Nana PhD student Danielsen Birgitte Kortegaard PhD student Fenger-Nielsen Rasmus PhD student Hermesdorf Lena PhD student Hornum Mikkel Toft PhD student Kylborg Sarah Estela PhD student Liu Yijing PhD student Pedersen Emily Pickering PhD student P
ANNUAL REPORT 2020 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