A5062411285- Climate change and permafrost
- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Peatlands and Wetlands Ecology
- Atmospheric and Environmental Gas Dynamics
- Methane Hydrates and Related Phenomena
- Indigenous Studies and Ecology
- Arctic and Antarctic ice dynamics
- Wildlife Ecology and Conservation
- Rangeland and Wildlife Management
- Geophysical Methods and Applications
- Polar Research and Ecology
- Species Distribution and Climate Change
- Climate variability and models
- Mercury impact and mitigation studies
- Soil Moisture and Remote Sensing
- Geological Studies and Exploration
- Avian ecology and behavior
- Geochemistry and Geologic Mapping
- Land Use and Ecosystem Services
- Climate Change and Environmental Impact
- Landslides and related hazards
- Ecology and Vegetation Dynamics Studies
- Geological Modeling and Analysis
- Seismic Waves and Analysis
Aarhus University
2012-2024
Minnesota State University Moorhead
2011
National Research Centre for the Working Environment
2006-2010
Mental Research Institute
2009
Environmental Research Institute
2009
Significance Wetlands are unique ecosystems because they in general sinks for carbon dioxide and sources of methane. Their climate footprint therefore depends on the relative sign magnitude land–atmosphere exchange these two major greenhouse gases. This work presents a synthesis simultaneous measurements methane fluxes to assess radiative forcing natural wetlands converted agricultural or forested land. The net impact is strongly dependent whether managed. Here we show that conversion...
Abstract. The northern latitudes are experiencing disproportionate warming relative to the mid-latitudes, and there is growing concern about feedbacks between this methane production release from high-latitude soils. Studies of emissions carried out in Arctic, particularly those with measurements made outside season, underrepresented literature. Here we present results 5 yr (2006–2010) automatic chamber at a high-Arctic location Zackenberg, NE Greenland, covering both seasons two months...
Abstract The land‐atmosphere exchange of methane ( CH 4 ) and carbon dioxide CO 2 in a high‐ A rctic wet tundra ecosystem R ylekærene) Z ackenberg, north‐eastern G reenland, was studied over the full growing season until early winter 2008 from before snow melt 2009. eddy covariance technique used to estimate fluxes combination gradient methods fluxes. Small bursts were observed during spring thawing 2009, but these existed short periods would not have any significant effect on annual budget....
This study describes and compares soil organic matter (SOM) quantity characteristics in two areas of continuous permafrost, a mountainous region NE Greenland (Zackenberg site) lowland Siberia (Cherskiy Shalaurovo sites). Our assessments are based on stratified-random landscape-level inventories profiles down to 1 m depth, with physico-chemical, elemental, radiocarbon-dating analyses. The estimated mean carbon (SOC) storage the upper meter soils site is 8.3 ± 1.8 kg C m-2 compared 20.3 2.2...
We have measured the land‐atmosphere CO 2 exchange using eddy covariance technique in a high Arctic tundra heath northeast Greenland (Zackenberg). On basis of 11 years measurements (2000–2010), it was found that snow cover dynamics important for exchange. The start uptake period correlated significantly with timing snowmelt. Furthermore, deep and long‐lasting snowpacks, following springs showed increased emission rates. In first part study period, there an increase approximately 8 g C m −2...
In this study, we quantified the spatiotemporal variability and trends in observations of multiple snow characteristics High Arctic Zackenberg Northeast Greenland through 18 years. Annual premelt snow-depth collected 2005–2014 along an elevation gradient showed significant differences depth between vegetation types. The seasonal cover was characterized by strong interannual region. Particularly timing snow-cover onset melt, annual maximum accumulation, varied up to order magnitude Hence,...
Abstract. An improvement in our process-based understanding of carbon (C) exchange the Arctic and its climate sensitivity is critically needed for response tundra ecosystems to a changing climate. In this context, we analysed net ecosystem (NEE) CO2 West Greenland (64° N) across eight snow-free periods 8 consecutive years, characterized key processes two main modulating components: gross primary production (GPP) respiration (Reco). Overall, acted as consistent sink CO2, accumulating −30 g C...
Abstract Plant biomass is a fundamental ecosystem attribute that sensitive to rapid climatic changes occurring in the Arctic. Nevertheless, measuring plant Arctic logistically challenging and resource intensive. Lack of accessible field data hinders efforts understand amount, composition, distribution, these northern ecosystems. Here, we present The aboveground synthesis dataset , which includes measurements lichen, bryophyte, herb, shrub, and/or tree (g m −2 ) on 2,327 sample plots from 636...
The Arctic is extremely vulnerable to projected climate change, and global warming may result in major community reorganizations. aim of this study was a thorough investigation plant biomass production throughout an entire growing season five different high arctic vegetation types: Cassiope, Dryas, Salix heath, grassland, fen. main focus on the gross ecosystem (GEP), biotic abiotic factors which influence GEP. Photosynthesis, aboveground biomass, carbon, nitrogen, chlorophyll content were...
Abstract Measurements of the land‐atmosphere exchange greenhouse gases methane (CH 4 ) and carbon dioxide (CO 2 in high Arctic tundra ecosystems are particularly difficult cold season, resulting large uncertainty on flux magnitudes their controlling factors during this long, frozen period. We conducted snowpack measurements these at permafrost‐underlain wetland sites Zackenberg Valley (NE Greenland, 74°N) Adventdalen (Svalbard, 78°N), both which also feature automatic closed chamber...
Abstract. There is a significant knowledge gap in the current state of terrestrial carbon (C) budget. Recent studies have highlighted poor understanding particularly C pool transit times and whether productivity or biomass dominate these biases. The Arctic, accounting for approximately 50 % global soil organic stocks, has an important role cycle. Here, we use CARbon DAta MOdel (CARDAMOM) data-assimilation system to produce pan-Arctic cycle analyses 2000–2015. This approach avoids using...
Abstract Snow is a key driver for biotic processes in Arctic ecosystems. Yet, quantifying relationships between snow metrics and biological components challenging due to lack of temporally spatially distributed observations at ecologically relevant scales resolutions. In this study, we quantified snow, air temperature, vegetation greenness (using annual maximum normalized difference index [Max NDVI ] its timing _ DOY ]) from ground‐based remote‐sensing observations, combination with...