Soil and Plant Community Characteristics and Dynamics at Zackenberg

• Main Authors: Elberling, Bo, Tamsdorf, Mikkel P., Michelsen, Anders, Arndal, Marie F., Sigsgaard, Charlotte, Illeris, Lotte, Bay, Christian, Hansen, Birger U., Christensen, Torben, Steen Hansen, Eric, Jakobsen, Bjarne H., Beyens, Louis
• Other Authors: Meltofte, Hans, Forchhammer, Mads, Rasch, Morten
• Format: Book Part
• Language: English
• Published: Elsevier 2008
• Subjects: Physical Geography; Arctic; permafrost; Zackenberg
• Online Access: https://lup.lub.lu.se/record/712868; https://doi.org/10.1016/S0065-2504(07)00010-4

Arctic soils hold large amounts of nutrients in the weatherable minerals and the soil organic matter, which slowly decompose. The decomposition processes release nutrients to the plant-available nutrient pool as well as greenhouse gases to the atmosphere. Changes in climatic conditions, for example, changes in the distribution of snow, water balance and the length of the growing season, are likely to affect the complex interactions between plants, abiotic and biotic soil processes as well as the composition of soil micro- and macro-fauna and thereby the overall decomposition rates. These interactions, in turn, will influence soil-plant functioning and vegetation composition in the short as well as in the long term. In this chapter, we report on soils and. plant communities and their distribution patterns in the valley Zackenbergdalen and focus on the detailed investigations within five dominating plant communities. These five communities are located along an ecological gradient in the landscape and are closely related to differences in water availability. They are therefore indirectly formed as a result of the distribution of landforms, redistribution of snow and drainage conditions. Each of the plant communities is closely related to specific nutrient levels and degree of soil development including soil element accumulation and translocation, for example, organic carbon. Results presented here show that different parts of the landscape have responded quite differently to the same overall climate changes the last 10 years and thus, most likely in the future too. Fens represent the wettest sites holding large reactive buried carbon stocks. A warmer climate will cause a permafrost degradation, which most likely will result in anoxic decomposition and increasing methane emissions. However, the net gas emissions at fen sites are sensitive to long-term changes in the water table level. Indeed, increasing maximum active layer depth at fen sites has been recorded together with a decreasing water level at Zackenberg. ...