Diagnostics and mapping of southern tundra habitats (on the example of Shapkina River key site)

Abstract

A classification of habitats is given for the area studied on the right bank of the Shapkina River, (East European tundra, southern subzone). The classification is based on the topographic position of biotopes and their plant communities. The mosaic of tundra vegetation makes it difficult for mapping. Usually in nature the combinations of plant communities are confined to specific types of habitats. To display the regularities of a fine-contour vegetation cover on maps, we used the habitat approach diagnosed by combinations of plant communities. The field survey was done in the summer of 2020; total area of about 150 km2 was surveyed. Ultra-high resolution (3–5 cm/px) aerial photography was carried out for key areas, using a DJI Mavic Pro Platinum quadrocopter (shooting height from 80 to 200 m). 25 geobotanical relevés were completed; in addition 180 short descriptions were made for map verification. All types of habitats in the proposed scheme are correlated with EUNIS units, lists of syntaxa are given. A large-scale map (1 : 50 000) of habitats was prepared. All tundra habitats are divided into two groups. First level of habitat classification confined to the main landscape types: watersheds and river valleys of watercourses with a floodplain regime. Watershed habitats are subdivided into 5 categories (second level of habitat classification), determined by their runoff-geochemical position on the generalized geomorphological profile (from the highest relief elements to the lowest ones), including underlying rocks, moisture regime and migration of elements, exposure features. Due to the small amount of data mapping of river valley habitats was performed only for units of the second level. At the third level watershed habitats are well diagnosed by vegetation at the level of associations, combinations of commuities, soil cover, and microrelief. As a result, most units of the second and third levels are clearly distinguished on aerial photography obtained using a quadrocopter, and also correlate with specific syntaxa. As a result of field data and aerial photographs analyses, 12 categories of habitats, represented by 17 syntaxa, were identified for watersheds at the 3rd level.