Soils on the southern border of the cryolithozone of European part of Russia (the Subpolar Urals) and their soil organic matter fractions and rheological behavior

Abstract Soil organic matter (SOM) plays an important role in the functioning of mountain ecosystems. This article contains the results of a study on SOM of high-latitude soils of the Subpolar Urals and its influence on the deformation behavior of soils. The first approach of this study was to define the soils of the Subpolar region to identify the main soil types and their morphological and chemical properties. We investigated soil types of mountain-forest, subalpine and alpine tundra vegetation zones, as well as soil types with permafrost. We investigated SOM using the method of physical fractionation, which isolates three fractions of SOM: free particulate organic matter (fPOM 1.6). The deformation behavior of soils was studied using rheometry. Based on the results, SOM mainly consisted of heavy-fraction MaOM 1.6 (−0.86, p