Выпуск: 4 , Том: 13 , Год издания: 2020

Highly detailed images acquired using unmanned aerial imaging made it possible to describe the structural features of a certain type of thermokarst depression. These depressions developed in edoma deposits in the southern part of the typical tundra subzone in the Lena Delta. The geomorphology and vegetation of the model depression are characterized by a combination of GIS analysis and ground survey. Detailed mapping has shown that the surface of the depression bottom consists of a baidjarakh field covered by the complex vegetation of highly productive plant communities dominated by grasses and graminoids. A comparison of satellite images and topographic maps from different years has shown that the depression appeared from a shallow thermokarst lake drained no later than 40 years ago. The depression terrain and vegetation are determined by its origin and the composition of the surface geological substrate. Depression vegetation is quite a contrast to zonal tundra in regards to its structure and floristic composition. It contains few species which tend to be more typical for southern distribution. Such spots serve as feeding places for herbivorous animals and, in the past, may have been an important part of the Pleistocene megafauna forage. Thermokarst events were typical for the ice-complex through the whole period of its formation, but might differ in intensity and area depending on climate conditions. Nowadays, the size and lifetime of thermokarst lakes depends on their position in the terrain and the thermoerosion intensity. In the tundra landscape, thermokarst plays an important role in the creation of new habitats and biodiversity support for plants and animals.