Vegetation recovery of Arctic disturbed permafrost
Sergei P. Davydov1, Anna I. Davydova1 & Dmitry G. Fyodorov-Davydov2
1North-East Science Station, Pacific Geographical Institute FEB RAS. Cherskiy, 678830 Russia 22Institute of Physicochemical & Biological Problems in Soil Science RAS. Pushchino, 142292 Russia
A ten-year study for vegetation recovery at disturbed Pleistocene loess-rich permafrost of Ice Complex in three stream goldfields of the Kolyma Lowland, Eastern Arctic has been carried out. The observations of mining removed deposits gave a possibility to study in more detail the succession recovery for disturbed and thawing permafrost. In the year of the disturbance and the first season after - thawing ground is covered with pioneer species of mosses (dominated by Funaria hydrometrica) and single shoots of Tephroseris palustris. Second year – T. palustris is dominated by seedling emergence of Arctagrostis latifolia at dry grounds and single shoots of Tripleurospermum hookeri and Salix sp. (not all sites). 3 years - expansion for T. hookeri and A. latifolia and emergence of shoots of Chamaenerion angustifolium and of Calamagrostis purpurascens. Pioneer moss species have almost disappeared. 4 years – continued expansion and co domination of T. hookeri and C. angustifolium with C. purpurascens and less A. latifolia. Salix species shoots expanded. Almost pure meadows of these herbs dominate especially on the valley sides with additional moisture. The more years that have passed since the disturbance, the more so, the vegetation restoration is developing along different trajectories. After 4-5 years on the disturbed sediments meadows of Calamagrostis purpurascens with A. latifolia and Salix pulchra,S. alaxensis and other Salix species developed at the southern valley sides of streams. Abundance of willow grows and suppresses herbs after 6-7 years. Appearance of dwarf shrubs and single Larix cajanderi shoots occurs at 8-9 year. Vegetation recovery significantly reduces the carbon flux input from disturbed permafrost beginning with 2-3 years after the disturbance.