SOIL TEMPERATURE REGIME IN POSTAGROGENIC ECOSYSTEMS UNDER THE EXPANSION OF SELF-RESTORING SUCCESSION OF TUNDRA VEGETATION (EUROPEAN NORTHEAST OF RUSSIA)
The peculiarities of soil temperature regime and permafrost table depth in the postagrogenic meadow ecosystems developing in the cryolithozone in the European north-east of Russia in the context of the self-restoring tundra vegetation succession expansion have been investigated (2009-2016). A comparative assessment of the studied parameters with those pertained to meadow (agrogenic) ecosystems in the period of their agricultural development (1996-1999) is provided. Recent increase in the temperature of loamy Anthrosols and Stagnosols is associated with the permafrost table depth changing from relatively shallow to below 2 m as a result of climate change-driven activation of the self-restoring tundra vegetation succession. Speciﬁcally, within the observation sites located on the river terrace and watershed, the increased soil temperature during the study period has prompted an increase in the active layer thicknesses from 1.5 to 1.8 m and from 1.8 to 2.0 m, respectively.