CARBON AND NITROGEN CONTENT AND RESERVES IN TERRESTRIAL ECOSYSTEMS OF THE MURMANSK REGION

Abstract

The article provides an overview of own and literature data on phytomass reserves, carbon and nitrogen content, diversity of soil fauna and mycobiota in terrestrial ecosystems of the Murmansk region under conditions of combined action of natural and anthropogenic factors. The environmental factors determining the functioning of ecosystems, including the regulation of carbon cycles, are considered. It is shown that in representative spruce and pine forests, the concentrations and precipitation of carbon compounds from the atmosphere and its removal from soil waters are higher in the subcron spaces than in the intercron spaces. In soil waters, there is a decrease in carbon removal with the depth of the soil profile. The podzols are characterized by a bimodal distribution of humus over the soil profile with maxima in the organogenic and illuvial horizons. The carbon content in the organogenic horizon of the soils of spruce and pine forests varies from 12 to 54%, nitrogen — from 4.7 to 18.7 g/kg. The main carbon reserves in the organogenic horizon of forest soils are concentrated in the sub-crown spaces and reach 27–34 t/ha. Carbon reserves in the meter layer of soil (mineral horizons) are 47–60 t/ha. The phytomass reserves of the North taiga forests are characterized by low values (12–188 t/ha). Significant reserves of plant organic matter of the North Taiga forests are concentrated in the ground cover. The carbon content in the assimilating organs (leaves/needles, shoots) of plants of the North Taiga forests varies from 35 to 73%, nitrogen — from 5.4 to 23.6 g/kg. The rate of decomposition of plant residues and carbon loss during the decomposition of the fall of evergreen plants in spruce forests is higher than in pine forests, as are the indicators of the number of soil macrofauna. The podzols of the North Taiga forests correspond to the predominance of secondary destroyers of plant litter — humifiers of earthworms and mixophages wireworms, litter mollusks) and the absence of calcifilic groups of mineralizers (woodlice, bipedal millipedes). 122 species of microscopic fungi have been isolated from the soils of the Murmansk region. Species of pp. Penicillium and Umbelopsis were dominant in terms of abundance in the background soil, in anthropogenically altered soils — species of pp. Aureobasidium, Penicillium, Trichocladium, Trichoderma and Umbelopsis.