Soils on coarse materials formed in the Vychegda and Pechora river basins (Spodosols) and the Barents See coast (Cryosols) are studied. Analyses of genetical peculiarities of soils showed interconnection between the morphological features and properties of soils in toposequences.

Micromorphological studies may show the evidence that fine dispersed material in forest soils is mainly concentrated on grain surfaces (heterogeneous films). In tundra soils finer matrix material is accumulated in spaces between coarse grains as a result of cryogenic aggregation and coagulation. Thin brownish films on sceleton grains are observed, too.

Filmy fabric (granostriated b-fabric) of finer matrix material in illuvial horizon and physico-chemical properties of forest soils reflect the main pedogenic processes - downward migration of Al-Fe- organic compounds. Heterogeneous character of films with embedded silt particles may show the evidence of clay and silt migration.

Fabrics specific to permafrost-affected soils characterized by aggregated (granular-like) types are related to cryogenic soil-forming processes. Illuviated type of fine dispersed mass distribution in forest soil profiles is gradually replaced with accumulative-illuvial type in the Arktic soils. Increasing of film thickness and colour intensity is connected with climatic and topographical humidity in Spodosols and show the changes in Al-Fe - organic compounds migration.

Universal soil-forming processes on coarse materials in forest and tundra soils are as follows: 1) organic matter turnover, 2) Al-Fe- organic compounds migration. Intensity of this processes is different. Specific to permafrost-affected soil processes are: 1) cryogenic structural units formation, 2) cryoturbation. Buried humus pedorelics were found in poorly drained sites, in sands underlain by loams in the Vychegda river basin.

Dr. Galina V. Rusanova
Institute of Biology
Komi Science Centre
Russian Academy of Science
167000 Syktyvkar, Russia
Fax: (8212) 420163