A5002259502- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Cryospheric studies and observations
- Geological Studies and Exploration
- Peatlands and Wetlands Ecology
- Hydrocarbon exploration and reservoir analysis
- Atmospheric and Environmental Gas Dynamics
- Indigenous Studies and Ecology
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Soil Carbon and Nitrogen Dynamics
- Marine and environmental studies
- Landfill Environmental Impact Studies
- Winter Sports Injuries and Performance
- Polar Research and Ecology
- Soil and Unsaturated Flow
- Food Industry and Aquatic Biology
- Groundwater flow and contamination studies
- Soil and Water Nutrient Dynamics
- Coastal wetland ecosystem dynamics
- Microbial Community Ecology and Physiology
- Aquatic and Environmental Studies
- Fire effects on ecosystems
- Ecology and biodiversity studies
- Odor and Emission Control Technologies
Universität Hamburg
2013-2023
Soil Science Research Unit
2023
Hamburg Institut (Germany)
2011-2021
Arctic and Antarctic Research Institute
2018
Institute of Soil Science
2007-2016
Universiti of Malaysia Sabah
2011
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2003-2007
Technical University of Munich
2007
Osnabrück University
2007
Institute of Groundwater Ecology
2007
Abstract Eddy covariance measurements of methane flux were carried out in an arctic tundra landscape the central Lena River Delta at 72°N. The covered seasonal course mid‐summer to early winter 2003 and spring 2004, including periods thaw autumnal freeze back. study site is characterized by very cold deep permafrost a continental climate with mean annual air temperature −14.7 °C. surface wet polygonal tundra, micro‐relief consisting raised moderately dry sites, depressed ponds, lakes. We...
Abstract. Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies Siberian zone of continuous permafrost. The landscape on consists mainly late Holocene river terraces with polygonal tundra, ponds lakes, an active floodplain. island has been focus numerous multidisciplinary studies since 1993, which have focused climate, land cover, ecology, hydrology, permafrost limnology. This paper aims to provide a framework for future by describing characteristics...
Benthic fluxes of dissolved oxygen and ammonium were measured at bi-weekly to monthly intervals during 1990-91 proximate under an array pens holding Atlantic salmon Salmo salar Linn. in L'Etang Inlet, a macrotidal embayment the Bay Fundy, Canada.Hierarchical clustering data indicated that 7 stations could be divided into 3 groups (3 pen array, 2 perimeter away from pens).Average rates uptake release for 4 27 times higher, respectively, than values distant cages.Maximum average (38 mm01 m-2...
The currently observed Arctic warming will increase permafrost degradation followed by mineralization of formerly frozen organic matter to carbon dioxide (CO2 ) and methane (CH4 ). Despite increasing awareness vulnerability, the potential long-term formation trace gases from thawing remains unclear. objective current study is quantify release matter. Therefore, Holocene Pleistocene deposits were sampled in Lena River Delta, Northeast Siberia. contained between 0.6% 12.4% carbon. CO2 CH4...
Abstract Permafrost environments within the Siberian Arctic are natural sources of climate relevant trace gas methane. In order to improve our understanding present and future carbon dynamics in high latitudes, we studied methane concentration, quantity quality organic matter, activity biomass methanogenic community permafrost deposits. For these investigations a core Holocene age was drilled Lena Delta (72°22′N, 126°28′E). The sediments varied between 0.6% 4.9% characterized by an...
The large amounts of soil organic matter (SOM) in permafrost-affected soils are prone to increased microbial decomposition a warming climate. environmental parameters regulating the production carbon dioxide (CO2) and methane (CH4), however, insufficiently understood confidently predict feedback thawing permafrost global warming. Therefore, effects oxygen availability, freezing thawing, temperature, labile (OM) additions on greenhouse gas were studied northeast Siberian polygonal tundra...
1. Methane (CH4) oxidation (methanotrophy) associated with submerged brown moss species occurs in polygonal tundra environments of the Siberian Arctic. Methanotrophic bacteria living close association mosses are thus not restricted to Sphagnum and low-pH peatlands. 2. Moss-associated methane (MAMO) can be an effective buffer for CH4 emissions from permafrost-affected tundra, a region that is high importance global greenhouse gas budget. Combining biogeochemical molecular approaches revealed...
Abstract. The Lena River Delta, which is the largest delta in Arctic, extends over an area of 32 000 km2 and likely holds more than half entire soil organic carbon (SOC) mass stored seven major deltas northern permafrost regions. geomorphic units Delta were formed by true deltaic sedimentation processes are a Holocene river terrace active floodplains. Their mean SOC stocks for upper 1 m soils estimated at 29 kg m−2 ± 10 14 ± 7 m−2, respectively. For depth m, total pool was 121 Tg...
Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil (SOC) stocks provide an important resource for researchers, natural managers, and policy-makers working towards the protection, restoration, valuation these ecosystems. We collated a global dataset tidal marsh (MarSOC) from 99 studies that includes location, depth, site name, dry bulk density, SOC, and/or matter (SOM). The MarSOC 17,454 points 2,329 unique locations, 29 countries. generated...
Abstract Permafrost soils of high‐latitude wetlands are an important source atmospheric methane. In order to improve our understanding the large seasonal fluctuations trace gases, we measured CH 4 fluxes as well fundamental processes production and oxidation under in situ conditions a typical polygon tundra Lena Delta, Siberia. Net were from depression rim end May beginning September 1999. The mean flux rate was 53.2 ± 8.7 mg m −2 d −1 with maximum mid‐July (100–120 ), whereas dryer part 4.7...
Abstract. The exchange fluxes of carbon dioxide between wet arctic polygonal tundra and the atmosphere were investigated by micrometeorological eddy covariance method. investigation site was situated in centre Lena River Delta Northern Siberia (72°22' N, 126°30' E). study region is characterized a polar distinctly continental climate, very cold ice-rich permafrost its position at interface Eurasian continent Arctic Ocean. soils are high organic matter content, low nutrient availability...
Methane (CH 4 ) emission patterns were investigated at an old landfill in northern Germany during a 2‐year campaign over three different time‐scales (seasonal, daily and diurnal) using modified static chambers. Emissions not uniformly distributed the cover soil, but occurred through localized preferential pathways (hotspots). The range of emissions from 14 hotspots any one measurement event was large, reflecting large spatial variability landfill. In addition, individual showed temporal...
Abstract. Soils are an important compartment of ecosystems and have the ability to buffer immobilize substances natural anthropogenic origin prevent their movement other environment compartments. Predicted climatic changes together with influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching migration trace elements in permafrost-affected soils. This is especially since considered be highly sensitive as well chemical contamination. study...
Abstract. Natural peatlands are important carbon sinks and sources of methane (CH4). In contrast, drained turn from a sink to source potentially emit nitrous oxide (N2O). Rewetting thus implies climate change mitigation. However, data about the time span that is needed for re-establishment function by restoration scarce. We therefore investigated annual greenhouse gas (GHG) balances three differently vegetated sites bog ecosystem 30 years after rewetting. All vegetation communities turned...
Abstract Methane (CH 4 ) production, oxidation, and emission were studied in ponds of the permafrost‐affected polygonal tundra northeast Siberia. Microbial degradation organic matter water‐saturated soils is most important source for climate‐relevant trace gas CH . Although lakes cover a substantial fraction land surface northern Siberia, data on fluxes from these water bodies are scarce. Summer measured with closed chambers at margins vegetated by vascular plants their centers without...
Abstract. Permafrost-affected soils have accumulated enormous pools of organic matter during the Quaternary period. The area occupied by these amounts to more than 8.6 million km2, which is about 27% all land areas north 50° N. Therefore, permafrost-affected are considered be one important cryosphere elements within climate system. Due cryopedogenic processes that form particular and overlying vegetation adapted arctic climate, has present extent up 1024 Pg (1 = 1015 g 1 Gt) soil carbon...
The bacterial community composition of the active layer (0–45 cm) a permafrost-affected tundra soil was analysed by fluorescence in situ hybridisation (FISH). Arctic soils contain large amounts organic carbon, accumulated thick layers and are known as major sink atmospheric CO2. These totally frozen throughout year only thin is unfrozen shows biological activity during short summer. To improve understanding how carbon fluxes controlled, detailed analysis composition, functionality...
Abstract. Permafrost-affected tundra soils are significant sources of the climate-relevant trace gas methane (CH4). The observed accelerated warming arctic will cause deeper permafrost thawing, followed by increased carbon mineralization and CH4 formation in water-saturated soils, thus creating a positive feedback to climate change. Aerobic oxidation is regarded as key process reducing emissions from wetlands, but quantification turnover rates has remained difficult so far. application...