卷 108, 编号 11 (2023)

A detailed geobotanical characteristic of Siberian dwarf-pine (Pinus pumila (Pall.) Regel) communities of the north of the Koryak District is presented. The vegetation classification based on 83 relevés has been elaborated using main principles and classification methods of Russian dominant-determinant approach. As the result 10 associations, 10 subassociations and 9 variants classified within 5 association groups were revealed. The peculiarities of their species composition, community structure, ecology and geographical distribution were characterized. Using soil characteristics, several types of sites were recognized. It was shown that mesophytic moss-rich dwarf-pine shrubs (Pinetum pumilae hylocomiosum) were closely connected to the mean values of soil moisture and soil fertility of the sites. Rhododendron-rich dwarf-pine communities (subass. Pinetum pumilae rhododendroso aurei–hylocomiosum) adjoined them but they usually occurred on higher altitudes. Lichen-rich dwarf-pine shrubs (Pinetum pumilae fruticuloso–cladinosum) occupied the driest and poorest sites at the upper border of dwarf-shrub altitudinal belt (350–400 m a.s.l.). The dwarf-shrub-rich Siberian dwarf-pine communities (ass. group Pineta pumilae fruticulosa) were closely connected to rather dry and poor sites. In wet sites with shallow groundwater, Sphagnum-rich dwarf-pine communities (Pinetum pumilae sphagnosum girgensohnii) were found. Cloudberry-rich dwarf-pine shrubs (subass. Pinetum pumilae chamaemori–rubosum) adjoined them but mainly occurred on the peat hillock of palsas. The variation in the species composition and structure of communities are determined by their position in the relief and the density of the dwarf-pine layer. With a similar density of dwarf-pine, Sphagnum-rich dwarf-pine communities form in the foothills, and lichen-rich dwarf-pine shrubs form in mountains. The species diversity and the abundance of the subordinate layers are significantly reduced at the maximum density of the dwarf-pine; so poor-herb dwarf-pine communities (Pineta pumilae oligoherbosa) are formed.

Based on the materials of the study of three artificial reservoirs located in the southern part of the Komi Republic, in the Vychegda River basin, it was shown that a characteristic feature of the overgrowth of the studied reservoirs is the predominance of sedge communities in its structure. There are three types of shallow water in the reservoirs: open, protected estuarine, and protected insular shallow water. For each type of shallow water, the formula and the degree of their overgrowth are determined. It has been established that the degree of overgrowth of the reservoirs and their coenotic composition largely depends on age (the time elapsed from filling the reservoir with water).

The paper presents the results of studying the distribution of stocks of potentially toxic elements (Ni, Cu) in subcrown spaces and “windows” of stands in medium-aged pine forests in the background area of the Kola Peninsula and that under environmental pollution by atmospheric emissions of the Severonickel Combine (Monchegorsk, Murmansk Region). On the basis of previously obtained data on the stocks of aboveground biomass of the components of the ground cover, mortmass of plant debris and forest litter and data of chemical analysis by means of atomic absorption spectrometry of leaves of dominant shrub species, aboveground parts of the moss Pleurozium schreberi (Brid.) Mitt, and lichen Cladonia stellaris (Opiz) Pouzar et Vězda, as well as plant waste and organogenic horizon (forest litter) of Al-Fe-humus podzols, Ni and Cu stocks in different components of forest ecosystems were calculated. It was found that the sharp decrease in atmospheric emissions by the Severonickel Combine over the last 20 years has not affected the level of habitat contamination, and the stock of heavy metals in the upper organogenic horizon of Al-Fe-humus podzols remains very high, especially in the impact zone, which does not even allow to start the process of restoration of the ground cover in this area. The stock of heavy metals in the plant waste consistently increases with the increase in the level of forest litter contamination when approaching the source of pollution, but the scale of this increase is significantly smaller in the mortmass compared to the litter. The pattern of distribution of heavy metal stocks in components of ground cover, plant waste and forest litter over the phytocenosis area is fundamentally different in background conditions and under aerotechnogenic pollution, which is due to differences in the accumulation of organic matter in different types of microsites. The ratio of Ni : Cu concentrations and stocks also differs in the soil-vegetation cover in pine forests of the background area and under the influence of aerotechnogenic pollution.

Information about the record of Halimodendron halodendron (Pall.) Voss in the Stavropol Territory is given. Its population, numbering about 200 plants, grows on the banks of the Nevolka River (basin of the Terek River) in the vicinity of Staropavlovskaya Village.

The article presents some scientific results of the 6th Western Himalayan Interdisciplinary Biogeographical Expedition of the St. Petersburg Union of Scientists. The flora and vegetation types of the central part, north-east, east and south-east of Himachal Pradesh state (India) were studied. The expedition participants studied plants at altitudes from 200 to 4600 meters. The difficult terrain, the variety of combinations of rocks, soil types, as well as abrupt changes in meso- and microclimatic conditions significantly influenced the nature of vegetation and the composition of flora, the definition of phytocenotic boundaries, the search for rare plants and the clarification of their ecology. Attention was also paid to cultivated component in plant communities. The article, based on the professional interests and individual view of each of the authors, briefly represents the diversity of vegetation along a route of almost 2000 km, passing through all the vertical zonality of the Western Himalayan biogeographical province.