Permafrost-hilly swamp complexes of the northern taiga of the Yenisei Siberia

The results of the study of two permafrost-hilly swamp complexes located in the valley of the Chernaya River, the right-bank tributary of the Yenisei River (near the city of Igarka), are presented. Among them are coarse-tuberous and flat-tuberous peatlands of different ages, genesis and stages of development. The modern vegetation cover of the complexes is characterized, a detailed morphostructural description of peat profiles is given, a botanical analysis is performed and the values of the degree of decomposition, ash content and moisture content of peat are determined. The thickness of the coarse-tuberous peat bog deposit is 4.0 m, the approximate age is 8 thousand years ago. In the process of its formation, it underwent six stages of change, of which the first was forest. The peat deposit is classified as forest-swamp and marsh subtypes. The main peat-forming agents from bottom to top of the profile were successively eutrophic hypnosis mosses, mosses (Hypnales W. R. Buck et Vitt), sedges (Carex L.), horsetails (Equisetum L.) and, finally, oligotrophic sphagnum mosses (Sphagnopsida Ochyra). The flat-tuberous peat bog with a capacity of 1.3 m and an age of about 3 thousand years in its development has gone through two stages of vegetation changes, of which the first is forest. Peat deposit of forest-marsh and marsh subtypes. Throughout its depth, ice layers are recorded. In the lower part of the peat profile, the main peat-forming agents were eutrophic hypnomic mosses, and in the upper part – oligotrophic sphagnum mosses. Changes in the vegetation cover of hilly peatlands occurred both as a result of changes in the regional climate in the Holocene, and due to the appearance of permanent permafrost in peatlands, heaving of mounds and their subsequent thawing. The appearance of spots of exposed peat on the day surface of peatlands and the formation of a powerful lichen cover in their place indicate the cessation of the peat formation process.