ИСТИНА

In 2008-2012, soil temperature {ST) measurements were performed at Russian Antarctic stations Bellingshausen (King George Island), Progress (Larsernann Hills), Druzhnaya-4 (Landing Nunatak), Molodezhnaya (Thala Hills), and Novolazarevskaya (Schirmacher oasis). The results are as follows. (1) Hard rocks have the highest summer and lowest winter STs. Moist soils (20 ern) have higher summer STs than dry soils due to a lower thermal conduction of the latter and to the convective transfer ofheat with melt water. Ice-rich soils have lower winter STs. (2) The coldest STs were recorded in the smallest oasis (Landing Nunatak): under lichens, the mean annual, January, and August STs (20 ern) were -12.1, -3,3 and -23, 7°C, respectively. (3) STs in wet valleys depend on the geographic latitude of the oases and their proximity to the sea. In the southernmost Schirmacher oasis far from the sea, the mean January ST (20 ern) was 3.4°C. In the northern coastal oases (the Thala and Larsernann hills), it was 4.1-4.4°C. Winter STs were lower in the Schirmacher oasis. (4) The transition from Antarctic to Subantarctic is marked by the rise in the winter STs rather than in the summer STs. (5) Soils under mosses have the lowest summer STs because of the insulating role of the moss and the impact of cold snowmelt from adjacent snow patches. The geographic distribution of STs under mosses follows the same regularities as those for the soils of barrens.