The article presents vegetation and climate reconstructions using quantitative methods (biomization and best modern analogues) based on pollen data from Petrovskoye Lake and Kosilovo Mire deposits, located in the marginal zone of the Valdai glaciation. The reconstructions cover the entire Holocene, during which mixed forests dominated. Five contrasting vegetation transitions are recorded: approximately 10 000, 9200, 7000, 4200, and 1200 years ago. In the Early and Middle Holocene, climate was the driver of these changes, and only the last transitions was driven also by anthropogenic factors, which are recorded using quantitative methods beginning around 4200 and 1200 cal BP.
For the first time, the influence of ambient temperature on the infection of bee colonies with the main diseases (varroosis, nosemosis, and Chalkbrood disease) in cyclonic climate conditions was studied. A statistically significant correlation was shown between the overall infection rate of colonies and the infection rate of bees with individual diseases and the average temperature of the winter months. The influence of temperature on the infestation of hybrid colonies, but not purebred ones, was revealed, which indicates better adaptation of bees of local origin to environmental factors.
Phytotoxicity assessment of metals in soils is typically conducted through laboratory testing. This study compares the field and laboratory evaluations of copper phytotoxicity in soils contaminated by copper mining and examines how test duration influences the observed toxicity. Barley shoots (Hordeum vulgare L.) and rhizospheric soils were sampled along a visible gradient of copper contamination in the Kargaly mining district (Orenburg Region, Russia). The soils, classified as chernozem (Mollisol), contained up to 7000 mg/kg of total copper, while concentrations of other elements remained at background levels, indicating a distinct monometallic contamination. Field experiments showed no statistically significant difference in the effective concentration causing a 50
Interspecific interactions within small-mammal communities can modify species-specific population characteristics depending on overall community state. Using a 21-year mark–recapture dataset from the forests of the Northern Urals, we examined how population density influences non-resident activity in three abundant species: red vole (Clethrionomys rutilus Pallas), common shrew (Sorex araneus L.), and Laxmann’s shrew (Sorex caecutiens Laxmann). We found a significant positive effect of heterospecific density on the number of moving (non-resident) individuals. Red vole, the dominant species in the community, exerted the strongest influence: its density significantly influenced non-resident activity both within its own species and in the two shrew species. In red voles, non-resident activity was primarily driven by total rodent density, with an additional significant effect of shrew density. In contrast, in both shrew species, total shrew density had the strongest effect, although rodent density was also significant. Non-resident activity was influenced not only by the density of resident populations but also by the density of moving (non-resident) individuals. Models incorporating non-resident density provided the best fit to the data. We suggest that at high population densities, the frequency of social contacts—including interspecific interactions—increases, thereby promoting movement.
The species-specificity of carbon exchange responses of Sphagnum communities to hydrothermal factors was studied in forest-mire habitats (Arkhangelsk region). Gross primary production (GPP) ranged from 0 to –2384.7 mg CO2/m2 h, and ecosystem respiration (ER) ranged from 45.2 to 1411.5 mg CO2/m2 h. The main factors regulating GPP were: for S. fuscum, the interaction of temperature regime and air humidity; for S. lindbergii, the combined effect of habitat water content and temperature; for S. divinum and S. squarrosum, air humidity and water content of the peat deposit. The ER regulation was also species specific and controlled by temperature or its interaction with other factors.
Macrozoobenthos in Sukhoe More Bay was assessed during spring 2024. A total of 14 species and intraspecific taxa were identified, with arthropods and mollusks predominating. Chironomid larvae and mollusks were the most frequent and abundant taxa, contributing the largest share of benthic biomass. Benthic development was highest in the northern (marine) part of the bay and near the inflow of the Mudyuga River, whereas lower abundance and biomass were observed in the central part of the bay near Cape Zayatskii and at the mouth of the Kad River. The quantitative characteristics of benthos indicate that the bay is a highly productive habitat for benthivorous fish. The resulting data provide a baseline information for environmental monitoring associated with port construction.
The most characteristic plant communities of the dwarf birches Betula nana and B. humilis were identified and described. The current range of B. nana and B. humilis in the Urals, Cis-Urals, and Trans-Urals was modeled using MaxEnt software, taking into account climatic and edaphic factors. The ecological optima of limiting factors for B. nana and B. humilis in the Urals are shown. The wider ecological range of B. nana compared to B. humilis allows this species successful adaptation to a wide range of altitudinal and latitudinal conditions, including mires of different trophic status. The dependence of B. humilis on the warm and cold quarters temperatures and the availability of groundwater determines its limited occurrence in the Ural Mountains.
Trophic fractionation or trophic discrimination factor, is a key parameter in the stable isotope-based studies in trophic ecology. In this study, we investigated nitrogen (Δ15N) and carbon (Δ13C) trophic fractionation (TF) in larvae of multiple species of leaf beetles (Coleoptera: Chrysomelidae) – a group of herbivorous arthropods that share similar trophic habits. Despite this ecological similarity, Δ15N values across species ranged from 0.9 to 6.8‰, and Δ13C values from –0.2 to 3.0‰, with even greater variation observed at the individual level. The Δ13C values showed no significant correlation with the dietary C : N ratio, while Δ15N values were positively associated with the dietary C : N ratio; however, the proportion of explained variance was very low. The apparent dependence of TF on the isotopic composition of the diet (δdiet values) was largely attributable to a spurious statistical association rather than a true biological mechanism. Our findings reveal substantial and unpredictable variability in TF even within a single insect family. While the mean Δ15N and Δ13C values were consistent with previously reported estimates, the extent of both inter- and intraspecific variation presents a major challenge for using TF as a precise tool for reconstructing trophic relationships. Field ecologists should acknowledge the variable nature of TF, which limits the precision of stable isotope-based trophic reconstructions.
Ecotoxicological studies on metal toxicity are commonly conducted using artificially contaminated soils, whereas investigations of naturally or industrially contaminated soils remain limited. Industrially contaminated soils often contain elevated concentrations of multiple elements, complicating the interpretation of toxic effects. This underscores the exceptional value of sites with monometallic pollution. One such site is the Kargaly copper mining district in the Orenburg Region of the Russian Federation. This study assessed copper phytotoxicity to sunflower (Helianthus annuus L.) grown under field conditions in soils historically contaminated by copper mining during the 18th–19th centuries. Total copper content in the studied soils reached up to 10 000 mg/kg, while the content of other elements remained close to the background levels, confirming the monometallic nature of the pollution. The effective concentrations of copper causing 25 and 50
The introduction of invasive earthworm species affects the nutrient cycle in the soil. Therefore, the effect of the native earthworm Eisenia nordenskioldi pallida, the invasive Aporrectodea caliginosa, and their combined presence on the availability of the water-soluble cations NH_4^ + , K+, Na+, Mg2+, and Ca2+ was studied. To achieve this, a field mesocosm experiment was conducted, and the cation content was measured by capillary electrophoresis. The experiment revealed that the invasive species only relatively weakly altered cation availability within a single growing season. The impact of A. caliginosa invasion depended on whether the soil was already inhabited by the native species or not. The effect of E. n. pallida on cation availability was studied for the first time.
Boreal forests are one of the planet’s largest carbon reservoirs. Pine forests of the green moss group of forest types predominate in Eastern Fennoscandia, which is characterized by the predominance of alfehumus soils of light granulometric composition. In the middle taiga communities of Karelia, in protective forests that occupy more than 30
The long-term (2001, 2010, and 2023) dynamics of the structure of epiphytic lichen communities on birch trunks were analyzed following the reduction of emissions from the Karabash Copper Smelter (Chelyabinsk oblast, Russia). A survey conducted in 2023, 7 years after emissions nearly ceased, revealed an increase in lichen species diversity in the background and buffer zones, partly due to the emergence of highly pollution-sensitive species. At the same time, the communities of the impact area are in an impoverished state, dominated by toxic-tolerant species, whose abundance remained unchanged throughout the study period. The consistent increase in similarity between the buffer and background zones suggests that recovery has begun, though at the time of the study, it was confined to the less polluted areas.
Length-weight relationship is an important tool in fish biology that provides insights into growth patterns of the fish and environmental conditions in its habitat. In the current study, the variability of the length-weight relationship of the Gangetic hairfin anchovy, Setipinna phasa (Hamilton, 1822) was correlated with the prevailing environmental factors. A total of n = 341 individuals of S. phasa (Engraulidae) were collected from the Ganga River and the Hooghly estuary. The changes in their growth in relation to their ecosystem type, developmental stages, and gender were studied. The fish living in estuarine waters showed an isometric growth pattern, characterized by smaller and plumper fish than those found in riverine waters, where a negative allometric growth pattern was observed. This change may be attributed to the variations in the diverse ecosystems. The b-values were found to be higher for juveniles and female individuals. The results of the Generalized Linear Model (GLM) analysis showed that the b-values were significantly influenced by the ecosystem type, environmental variables, developmental stages and gender. The results have significant implications for managing, conserving, and prioritizing fish populations for sustainable utilization in their respective habitats.
Using a field experiment in mesocosms during the growing season, we evaluated the effect of endogeic invasive earthworms: Eisenia tracta, Aporrectodea caliginosa, and the native E. nordenskioldi pallida, individually and when cohabiting, on the organic matter content in Calcic Chernozem soils. We established that the distribution of soil organic matter within the humus horizon depends on the earthworm species and their interactions. The highest content was observed in the variants containing the native species.
The relationship between the species richness of plant communities and aridity is analyzed using a formalized analysis of 12 300 georeferenced geobotanical descriptions. A correlation has been identified between these indicators. At Thornthwaite index = 45–50, the species richness of phytocenoses reaches the highest level; it is manifested in the southern part of the forest zone and in the lower part of the mountain forest belt, where rich communities with complex vertical structures are formed.
We analyzed the concentrations of 9 ions related to heavy metals (Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, Pb and metalloid As) (HM) in the feathers of pigeons captured in four districts of Moscow (VDNKh, Vykhino, Izmailovo, Orekhovo). In addition, HM accumulation in the black and gray parts of the feather in a particular bird were evaluated. Significant differences in the concentration of HM were found between locations in Moscow, which indicates a spatial heterogeneity of pollution. The analysis showed that the concentrations of all HM were significantly higher in the black parts of the feathers than in the gray ones. This confirms the chelating role of melanin, which accumulates in melanosomes. It has been shown that the shape and number of melanosomes also differ in the black and gray parts of the feather (in gray, the ratio of rod-shaped and rounded melanosomes is 1 : 3, and in black—5 : 1). The results confirm the possibility of using pigeon feathers for biomonitoring of HM and emphasize the critical importance of taking into account the type of pigmentation of the feather when interpreting pollution data.
It remains relevant to assess the carbon cycle in ecosystems formed after clear-cutting at different stages of secondary succession. This study was conducted from 2018 to 2023 in a community formed after clear-cutting of a bilberry pine forest in 2008 using chainsaws and by removal of tree-length logs. It is shown that carbon from the 1-m thick soil layer is the dominant pool, the proportion of which was 78
The taxonomic composition of diatoms and the content of plant pigments were studied in a 40-cm sediment core from a postglacial oligotrophic lake of marine origin located on the shore of the White Sea (Lake Krivoe, Northern Karelia). Based on the content of chlorophyll a, pheopigments, and organic matter, the lake’s bottom sediments (sapropelites) correspond to the hypertrophic category throughout the evolution of the lake (marine lagoon, meromictic lake, freshwater lake). In the upper layers of the core (i.e., in freshwater conditions), the richness of planktonic diatoms (Pantocsekiella, Stephanodiscus, and Aulacoseira) was low, indicating stable pelagic conditions. Pennate diatoms, which are periphytic and benthic producers, were highly diverse and abundant. Pigment content dynamics show a trend toward decreasing productivity to date.
Forest ecosystems of the boreal zone are the most vulnerable areas in terms of current climate change. CO2 fluxes from the soil surface are also significantly modified by sudden changes in environmental conditions. The main objective of this study was to trace the response of emission and exchange fluxes of CO2 from the soil surface in mid-taiga ecosystems to changes in moisture conditions during heavy precipitation. Direct chamber measurement methods during the frost-free period of the year were chosen as the research methods. It was found that for pine stands with different ground cover, microclimatic characteristics make a significant contribution to the formation of the CO2 flux. CO2 pulses in the ecosystem of the lichen pine forest throughout the season are manifested in an increase in the exchange CO2 CO2 by an average of 3–4 times. In a green moss pine forest, the value of CO2 pulses varies considerably during the season, reaching a maximum in the middle of the growing season: initial CO2 flux rates increased 5 times. With an increase in the amount of precipitation in the lichen pine forest, an intensification of production activity by 12
Intact broad-leaved forests were studied as reference ecosystems for developing up-to-date assessments of the capacity of forests to sequester carbon. The main study object was an old-growth forest with isolated windthrows and oaks over 300 years old. We assessed (1) the volumes of deadwood on transects, C and N stocks in deadwood, and (2) C and N stocks in two soil types dominating in the area: Albic Retisols (RT‑ab) and Luvic Phaeozems (PH-lv). Soil sampling was carried out independently of the transects. The contents and stocks of elements, the density and thickness of the humus horizon were compared between the two soil types, as well as beneath and adjacent to fallen trunks of pedunculate oak. Estimates of stocks in the old-growth forest were compared with the same estimates obtained earlier at two plots of mass windthrows located on RT-ab soils and Albic Podzols. The results obtained show that (1) the mean deadwood volume on transects was 182 ± 28.4 m3/ha, more than half of which was represented by oak at the first three stages of decomposition. The C and N stocks in deadwood were 19.2 and 0.2 t/ha. The volume of deadwood in the old-growth forest was 40
