No 1 (2023)

The low number of pollinating insects is the limiting factor for entomophilous plants in the north, and the situation is exacerbated by a short growing season and often unfavorable weather conditions for their life. The paper presents the results of studying the complex of pollinators of the specialized melittophilic species Veronica spicata at the northern limit of its distribution. It is shown that the structure of this complex is determined by the structural features of V. spicata flowers, the latitudinal position, and the  fferentiation of ecological niches of the species in the north. Unlike other parts of the range, where solitary bees play an important role in the pollination of V. spicata, this function in the north is performed by representatives of the genus Bombus Latr. (Hymenoptera, Apidae). Considering the level of species diversity and population structure,  the pollinator complex of V. spicata is based on short proboscis species of umblebees: Bombus lucorum s.l., B. jonellus, B. pratorum, B. sporadicus, and medium proboscis B. pascuorum. In accordance with the differentiation of ecological niches of V. spicata in the north, differences in the structure of the pollinator complex and foraging strategies of bumblebees were revealed.

The specific features of the soil–vegetation heterogeneity at the early stages of restorative succession have been studied. These features are determined by biotic and bioinert conditions that were influenced by anthropogenic factors during long-term plowing on azonal carbonated soils in the middle taiga subzone (Kargopol district, Arkhangelsk Oblast, Russia). In total, 25 full-profile soil sections, 500 soil samples, 125 sites for counting tree and shrub species, 25 standard geobotanical plots, and 250 plots for counting herbaceous species have been studied and analyzed. During the first 15 years of restorative succession on fallow agricultural land, herbaceous vegetation has the highest phytocenotic significance. On the residual calcareous soils of the forest zone, the specialization of ecological properties, i.e., the confinement of species to certain factors is weakly pronounced only in some herbaceous species. The mosaic structure of vegetation cover on a 15-yearold fallow is determined not by the variability of soil properties and the influence of growing tree and shrub species, but by the biological properties of herbaceous plants and their specific requirements for environmental factors. Soil fertility and soil moisture are the main factors that determine the variations of vegetation at this stage.

The environmental preferences of the bank vole were studied in the protected area of the Middle Urals in different biotope conditions formed as a result of the consequences of natural catastrophic events. According to the abundance of the population, the “success” of the existence of the species in four biotopes with varying degrees of disturbance by wind and pyrogenic effects was assessed. A statistically highly significant level of differences between the compared biotopes was shown for six microenvironmental variables that assess the food-protective conditions of animal habitats. In general, the biotopic variability turned out to be higher than the chronographic (interannual) variability. Over the long period of the study, the bank vole prevailed in numbers in the undisturbed biotope, which was distinguished among the studied biotopes by high values of microenvironmental indicators that assess mainly the food resources of animal habitats: the coverage of areas by shrubs and herbaceous vegetation. Habitat conditions in the biotope undisturbed by natural catastrophic factors are most consistent with the environmental preferences of the bank vole.

Cold waters and low productivity of the reservoir create energetically special conditions for the life of aquatic organisms, which are exacerbated by the current climate change. The temperature-dependent indicators of energy metabolism (active metabolic rate) have been studied for the representatives of different ecological– iogeographic groups of amphipods: arctic (Gammaracanthus loricatus), palearctic (Gammarus zaddachi), and holarctic (G.lacustris), from the coastal lake and the littoral of the White Sea basin. Interspecific differences in the standard energy metabolism rate and its 1.5–2.0-fold increase for predating amphipods are found.