Vegetation dynamics of landslide affected slopes (central Yamal)

Abstract

One of the topical issues arising due to the development of natural resources and the climate change in the Arctic Region is the prediction of ecosystems’ dynamics, based on the study of tundra biota response to the different natural and anthropogenic impacts. The cryogenic landslides’ process appears to be one of the determining factors of the ecotopes’ transformation in the various tundra regions including the Central Yamal. The process is influencing vegetation of vast areas, its structure and dynamics. The structure of plant communities is an important factor of the cryogenic landslides’ activation. The ecotopes of the later vegetation demutation stages’ communities are the most resistant to the development of the process. These communities have a closed shrub cover of Salix glauca (that is often 1–1.5 m high). At the subclimax stage this cover gets thinned, and the mosses begin to dominate by the phytomass. In subclimax communities there are no plants with extensive root systems capable to “retain” the structure of the active layer; therefore their ecotopes turn out to be extremely non-resistant to the development of the landslide process. Geochemical processes proceeding in the active layer also lead to the ecosystem destabilization through slow accumulation of secondary clay minerals on the border between active layer and permafrost. These minerals play a significant role in cryogenic landslides’ development. The strain in upper deposits’ horizons, which is also necessary for the landslide process activation, is accumulated gradually.