The aim of research - by using C-fractions of the soil organic matter (SOM) and isotope investigation - is to characterize recent decomposition processes of SOM due to the patterned ground and under the different climatic zones. The 13C value of the carbon fractions will help to understand their role for the carbon decay under permafrost conditions.

The important site parameters of different patterned grounds and their mineral soils are monitored (structure and decomposition of organic matter in the active layers, texture and structure, transition to the permafrost layers, etc.) The main parameters of carbon-cycle (temperature, acidity, moisture, redox) are meausred. The SOM including the dissolved organic carbon (DOC) are fractionated by density and by special resins exchange. The 13C-values will be determined of these fractions and of the plant sources.

The investigation areas are located at the Labaz Lake (72oN, 100oE) amd the Bolschewik Island/Severnaja Zemlija (79oN, 101oE). The landscape of Labaz Lake is characterized a moderately hilly landform with lake depression and solifluction features. The main vegetation types are treeless, subarctic tundra differentiated by the soil moisture conditions. The climate is characterized by a mean July air temperature of 12oC (mean annual air temperature: -13oC) and a mean annual precipitation of about 235 mm. Dominant are gleyic soils with different aquic soil regimes. Above the permafrost tale often an accumulation zone of organiz material and reduced oxides could be recognized. Typical patterned grounds are nonsorted polygons, nonsorted circles and earth hummocks. The thickness of the active layer range between 0.5 and 0.7 m depth. In contrast to the distinctly developed tundra soils of Labaz Lake, the soils of the Severnaja Zemlija site are rather virgin. The climate is characterized by a mean July air temperature of 3oC (mean annual air temperature: - 13oC) and mean annual precipitation of about 60 mm. Typical soil surface features are weak nonsorted circles, polygons and nets with weak differentiated crysols - including wet and organic rich, arctic desert soils. The comparison of SOM at the different sites will reveal detailed information of the carbon turnover under the different climatic conditions (subarctic-arctic).

Andreas Gundelwein
Institute of Soils Science
University of Hamburg
Allende Platz 2
20146 Hamburg, Germany
Phone: 040.4123.6595
Fax: 040.4123.2024
E-mail: bk5a001@boku.ifb.uni-hamburg.de