Spatial variability and cryogenic impacts on nutrient availability in a polygonal tundra landscape in north-east Siberia

摘要

Polygonal tundra is characteristic of poorlydrained permafrostlandscapes. Frost cracks are filled in spring by re-freezingmelt water. Annual repetition of this process leads to the formation of ice-wedge polygons [French, 2007]. Elevated polygon rims and depressed polygon centers form a very heterogeneous landscape which has been investigated to be today a carbon sink [Wille et al., 2008] But further development of arctic ecosystems depends on complex interactions between hydrology regime, plant-species composition and nutrient supply [Weintraub&Schimel, 2005; Schuur et al., 2008]. Hence, understanding of the nutrient dynamics in arctic soils is an important factor to predict further responses of arctic ecosystems to climate change.