Home – Home – Jornals – Contemporary Problems of Ecology 2024 number 6

The data obtained on the qualitative and quantitative composition of summer phyto- and zooplankton of two lakes of the Taimyr Peninsula indicate a higher trophic status of the water body, which is under pressure from hydrophilic birds. Compared to the background water body, statistically significantly higher phytoplankton abundance (134.6 ± 16.3 thousand cells/l vs. 60.4 ± 11.8 thousand cells/l), zooplankton biomass (134.6 ± 16.3 thousand cells/l vs. 60.4 ± 11.8 thousand cells/l), zooplankton biomass (349.0 ± 170.2 mg/l vs. 64.5 ± 19.5 mg/l), rotifer biomass (15.6 ± 3.5 mg/l vs. 1.6 ± 0.4 mg/l) and their dominance, as well as saprobic index (1.71 ± 0.09 vs. 1.48 ± 0.06). At the same time, specific features of community organization were revealed - higher species richness of phyto- and zooplankton; absence of Cyanobacteria in phytoplankton composition and statistically significantly higher abundance of Bacillariophyta (80.7 ± 11.8 thousand kl./l vs. 31.7 ± 6.5 thousand kl./l), number of species (4 vs. 2) and biomass (326.6 mg/l vs. 60.6 ± 18.8 mg/l) of paddle-bearing crustaceans, which may be determined by the peculiarities of hydrobionts reaction to the products of bird activity. This allows us to speak about the prospects of guanotrophication to improve the trophic status of water bodies without significant deterioration of environmental quality and biodiversity of hydrobiont communities.

A generalization of the available information in the reproductive ecology of widespread bivalve from the families Margaritiferidae and Unionidae during the most vulnerable period of reproduction in their complex life cycle has carried out. In the course of data analysis, the features of evolutionarily adaptive strategy of mollusks to various environmental conditions and relationships with fish are revealed. From a detailed review and analysis of the reproductive cycles of mollusks from the genera Margaritifera, Unio and Anodonta, it is revealed that in the boreal region from subarctic and temperate continentalal to subtropical climates the temperature is the main factor regulating all stages and timing of the reproductive process.

Phylogeographic and morphological analyzes of the whitefish Coregonus lavaretus of Europe, the level of polymorphism of the mtDNA nd1 gene indicate a relatively ancient origin of the populations inhabiting water bodies west of Jutland. It is suggested that these populations in Europe represent remnants of the primary wave of settlement by founders from Central Siberia (Lena River basin). In later waves of whitefish migrations from Siberia, synchronized in time with the events of repeated Lower Quaternary glaciations, whitefish settled west of the Urals from the lower reaches of large watercourses of Western Siberia (Ob River, Yenisei River), which evolved relatively independently of whitefish from Central Siberia. As a result of repeated events of settlement from disconnected periglacial refugia from the east and west, in the geographical space of Eastern Europe from the Baltic Sea to the Pechora River, whitefish haplotypes were greatly mixed. In addition to natural-historical reasons, the distribution of genetic variability in natural whitefish populations in Eastern Europe in recent decades has been influenced by fish hatchery activities for acclimatization and/or artificial maintenance of populations/species.

Species composition and fatty acid composition, seasonal dynamics of biomass, production and productivity of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of the zoobenthos of the Ob River and its tributaries, the Inya River and the Tula River were studied. Total contents of EPA and DHA in all taxa of zoobenthos were relatively high, except of Trichoptera, Bivalvia and Gastropoda. Values of the EPA and DHA contents felt in the ranges reported in literature for the relevant taxa from various habitats, which confirms the hypothesis about the principal contribution of the phylogenetic factor to the contents of EPA and DHA of zoobenthos. As found, a similarity of the species composition between the Inya River and the Tula River was lower than that between the Ob River and each tributary, which may be due to different hydrological features and types of bottom sediments, as well as a drift of benthic invertebrates from the tributaries into the main channel. The Ob River, the Inya River and the Tula River had nearly similar values of zoobenthos production and EPA and DHA of productivity, while they differed from these parameters of the Yenisei River and its tributaries reported in literature, which had another species composition of benthic invertebrates. As found, the EPA and DHA productivity, i. e., the biochemical quality of the fish food under similar values of the production of zoobenthos, was determined by the species composition of zoobenthos, which depended on the complex of environmental factors.

The role of interspecific competition in biotic communities is poorly understood. The study deals with transformation of the Korean field mouse/stripped field mouse taxocene, which includes range expansion of the second one during global environmental change. The main goal is a comparative estimation of main intestine divisions’ length in these species to define their competitive asymmetry and to understand its role in the taxocene dynamics. We show that the assimilation carbohydrates prevailing in plant tissue is significantly more effective in the Korean field mouse intestine than in the stripped field mouse intestine, while their difference in the protein and lipid assimilation was low. We conclude that the Korean field mouse is the stronger trophic competitor in the taxocene, and the competition play an important role in its transformation. However, neither competition nor global change can directly influence range expansion of the stripped field mouse separately. A interactive mechanism of their influences on the Korean field mouse/stripped field mouse taxocene transformation is discussed.

Predators are an important factor in population dynamics and evolution. They not only kill their prey, but also induce adaptive changes in morphology, physiology and behavior. The relationship between the coat color of water voles, Arvicola amphibius (Linnaeus, 1758), and the predisposition to seizures in response to tactile stimuli was studied. Convulsive behavior is believed to have evolved in evolution as a reflex reaction that protects against sudden capture by a predator. It was found that among brown individuals the proportion of those prone to seizures was significantly higher than among dark brown and black individuals. A comparison of the frequencies of individuals of different color phenotypes in the natural population and in the prey of raptors using published data showed that black individuals are easier prey for predators. The occurrence of convulsive seizures when captured by a predator can disrupt the stereotypical hunting behavior of the predator and increase the likelihood of survival of brown individuals

The results of long-term observations are summed up, which made it possible to assess patterns and identify the reasons for changes in the numbers, current distribution and interspecific relationships of ungulates in the Ussuriysky Nature Reserve. A comparison of archival materials and data from the last decade shows that changes in the abundance and distribution of most ungulate species in the reserve are inextricably linked with the increase in the number of sika deer. After the introduction of this species into the territory over 70 years, its number increased from 25 to 1180 individuals, and the population density reached an average of 30 individuals/1 thousand hectares. Over the same period, the number of red deer in the Ussuriysky Nature Reserve decreased from 450 to 130 individuals, that is, more than three times. In the Suvorovsky forestry, there is currently a decrease in the number by about half (from 250-280 to 110 individuals); in the Komarovsky forestry, the number has decreased by about 10 times (from 180-200 to 15-20 individuals). The number and distribution of roe, musk deer and wild boar in the territory did not change so obviously. The current number of roe in the reserve is 170 individuals with a population density of 4 individuals/1 thousand hectares. The number of wild boars is about 200 individuals with a population density of 4-5 individuals/1 thousand hectares. The developed and applied accounting methodology made it possible to obtain reliable data on the number and distribution of ungulates throughout the Ussuriysky Nature Reserve. There are concerns about a further increase in the number of sika deer in connection with the implementation of biotechnical measures in the reserve.

We examined neuropteran assemblages of the Mordovia Nature Reserve collected in 2022 and 2023 using bait traps at the site of 2021 and 2010 fires and in areas not exposed to these fires. We found that the fires, in which almost all vegetation was destroyed, had different effects on different ecological groups of Neuroptera. Fires were favorable for chortobiont (herb-dwelling) species (e. g., Chrysopa abbreviata, Ch. walkeri, Ch. commata) and species preferring forest edges (e. g., Apertochrysa prasisa and A. ventralis) which increased their numbers. Such fires were, however, very unfavorable for dendrobiont (tree-dwelling) species, especially e. g., Nineta alpicola, N. vittata and Chrysotropia ciliata, which disappeared from burned areas or were unable to restore their numbers in this time.

Based on the well-known provisions of the general theory of systems, some key issues of successional transformations at the biogeocenotic (ecosystem), phytocenotic, microcenotic and population structural levels are considered on the example of post-fire successions in broad-leaved Korean Pine and dark coniferous Korean Pine forests of Sikhote-Alin. In research at the biogeocenotic level, long-term regime observations of individual environmental factors were used, as well as indicative methods based on the analysis of gradients of leading environmental factors by groups of indicator species, blocks of diagnostic species according to the Brown-Blanke ecological and floristic approach and regional ecological scales. The main attention at the phytocenotic level of the study of successions was paid to the issues of spatial structure, species and cenotypic composition of communities, dynamics of the number and productivity of communities. At the microcenotic level, the issues of transformation of the main elements of the mosaic of phytocenoses (synusions and microcenoses) and their equivalents in biogeocenoses (parcels) are considered. Ontogenetic states and the age structure of cenopopulations were established at the population level.

In dendroclimatic studies, there is a need for high-quality data series reflecting the state of the environment in the past. The construction of long-term tree-ring width (TRW) chronologies (in terms of the combined qualities of being one of the best sources of paleo-climatic information) is associated with the problem of finding a source of paleo wood, which will allow it to extend further into the past. The paper considers the prospect of extending the existing 2367-year TRW chronology (on the Siberian larch) due to the attraction of wood of Siberian pine, which is widely presented in collections collected on the premises of the Altai glaciers. The results of consideration of various parameters of annual rings, clearly and convincingly demonstrated that at the upper edge of the forest, the use of such parameter, as the delta of optical density of the annual ring will allow reliably to cross-date samples of different tree species and extend this TRW chronology to the past.

Changes in the soil hydrothermal regime caused by the permafrost layer melting, represent the most important environmental factor in the dynamics of vegetation cover in the permafrost zone. The impact of soil melting on the growth index (GI) of larch ( Larix spp.) and on the gross and net primary productivity (GPP, NPP) of vegetation in the Arctic region of Central Siberia (open woodlands, tundra and forest-tundra) was studied. The following hypotheses were tested: (1) gravimetric data make it possible to estimate the water mass dynamics in soils; (2) thawing of frozen soils stimulates the growth of woody plants and the productivity of vegetation. The work used dendrochronology methods, field data, satellite gravimetry (GRACE survey) and GPP (Terra/MODIS survey). Analysis of gravimetry data revealed a significant long-term trend in water mass decreasing in soils of the permafrost zone (R² = 0.68). The amount of water released during melting is estimated at 6.4 ± 2.3 kg/m^-2 per year. A close connection was found between larch GI and GPP with moisture anomalies in soils (r = - 0.7 and r = - 0.9, respectively). The increasing temperature of the root layer and the moisture deficiency in water vapor also have a positive effect on the GI of larch and the vegetation GPP value in general (r = 0.6 and r = 0.6…0.9, respectively). It was found that pyrogenic carbon losses are significantly (by two orders of magnitude) lower than the NPP value. In conditions of waterlogging of soils, typical for the Arctic, climate warming is accompanied by an improvement in the hydrothermal regime of vegetation growth, promotes an increase in vegetation productivity and the permafrost zone maintains the status of a carbon sink area.

Changes in the productivity of Pinus sylvestris L. were analyzed by remote sensing (gross and net primary production/photosynthesis) and dendrochronology (radial trunk growth) methods on two different-aged forest plots of ribbon pine forests in the dry steppe of Western Siberia. For both plots (young reforestation plantings and natural forest) a significant positive trend of primary production volume change over the period 2000-2023 was revealed. Differences in the set of climatic factors limiting stand primary production volume (spring and fall temperature and precipitation) and radial growth of pine were determined (last September temperatures are significant for pine of different ages, the sum of annual precipitation and Selyaninov hydrothermal coefficient of the growing season are also significant for young trees, and June temperature is also significant for mature forest). Correlations between the width of annual growth of model trees and primary stand production in June and early July for natural forest and in the second half of June for plantations were established. Calculations of the annual volume of carbon sequestration by trees based on tree-ring and biometric data showed that on average over the last 5 years, pine in the table fraction deposited from 525 g C/year (young plantings) to 565 g C/year (mature trees). The results of calculations of carbon sequestration volumes (for single-age pine plantations) are comparable in absolute terms and correlate with the values of primary stand production obtained remotely.

Fluctuation dynamics (studied for 9-27 years) of the abundance, density, age and spatial structure of Dactylorhiza maculata (L.) Soó population on Lake Dolgoe of the Volga-Kama Reserve reflects the mechanisms of maintaining the population at the southern border of the range. The data were stored into the database. Abiotic and biotic factors of transitional shrub-sedge sphagnum bogs are the most suitable for the conservation of a rare species, where boreal and arcto-boreal species are preserved, and favourable microsites are open and moist areas of the mire, with pH 4.1-4.5. The biodiversity of sphagnum mosses in the habitats of Dactylorhiza maculata is represented by 9 species, where the carpet species is Sphagnum angustifolium, and Sphagnum divinum appears in open and wet micro-areas, Sphagnum centrale appears in areas overgrown with open forest. A significant relationship of the species abundance with climatic factors revealed: positive relationship with precipitation, negative relationship with average temperatures of the growing season. The number of reproductive D. maculata does not depend on precipitation in moist microsites. Ontogenetic stages were reliably identified using the morphometric parameters of vegetative and reproductive plants: juvenile (j); immature (im); virginal (v); young reproductive (g1); mature reproductive (g2). The ontogenetic spectrum is 11.5: 17: 29: 42.5 (j: im: v: g), proportion of pre-reproductive individuals fluctuated between 57-66 % in the period of 9-27 years of study, due to a high percentage of fruit formation (up to 60 %). Spatial distribution of individuals predominantly is clustered, consisting of aggregations with a radius of 0.5-1.2 m, distributed randomly. The dynamics of spatial mosaics, accompanied by the migration of seeds and individuals of D. maculata to favourable microsites, is a natural compensatory resistance mechanism that ensures the dynamic balance of the population.

For the first time in Central Siberia, in the parks of Krasnoyarsk, on Pinus sylvestris L. trees of different ages with different phytopathological conditions, we identified the invasive species Diplodia sapinea (Fr.) P. Karst., which is a dangerous pathogen of coniferous trees. Pure cultures were isolated from pycnidia on cones; their morphological and molecular genetic characteristics correspond to the species D. sapinea. Siberian isolates are characterized by a high radial growth rate on nutrient media; are phytopathogenic against shoots of P. sylvestris and fruits of Granny Smith apples in vitro. They cause rapid and extensive necrotic lesions of the bark, shoot cambium and fruit pulp; exhibit high peroxidase and protease enzymatic activity. Siberian isolates of D. sapinea do not exceed the parameters of southern isolates in terms of morphological characteristics, enzyme activity and phytopathogenicity. Significant differences are shown with the Dp1-23 strain of Diplodia seriata De Not, isolated from pycnidia on the cones of Cupressus sempervirens L. For Siberian isolates of D. sapinea, high resistance to cold stress was established in the temperature range from -8 to -31 °C in a series of experiments on freezing and thawing of the mycelium. After activation, the radial rowth rate of isolates on PDA at 24 °C turned out to be higher than that of strains that were not subjected to freezing; relatively slow activation was noted at -16 °C compared to other temperatures. The presence of a long endophytic phase in a species first discovered in Central Siberia, high adaptive capabilities and phytopathogenicity pose a particular danger to its spread to a new territory and host plants, which requires special attention and study.

Plant communities sufficiently change microclimate under their canopy. To reveal the effects of different types of herbaceous communities on the soil thermal regime, phytomass and soil temperature were measured in four plant communities of the Central Forest State Nature Bioshpere Reserve and its surroundings (Tver` oblast`). The productivity of the studied communities ranged in the order: abandoned meadows (930 ± 53 g/m²) - managed meadows (1111 ± 40 g/m²) - Filipendula ulmaria communities (1357 ± 155 g/m²) - subruderal tallherb communities (1726 ± 188 g/m²). The belowground phytomass in the 0-5 cm layer ranged on average from 614 ± 102 g/m² in the subruderal community to 1756±448 g/m² in the Filipendula ulmaria community. The total phytomass was positively correlated with the soil pH (R = 0.814, p < 0.001, n = 16), as well as with nutrient availability indicator values (R = 0.528, p = 0.029). In all the communities the temperature maximum coincided with that of air temperature and occur in June-July. In winter, soils at 8 cm did not freeze, but some days surface temperatures dropped below zero. Soil water capacity was significantly negatively correlated with mean temperatures at the depth of 8 cm in July, August, and September. The links with soil surface temperature were similar, but less pronounced. Soil temperatures at the peak of the growing season and in the following months were not significantly correlated with aboveground phytomass values. Thus, in the forest zone even within relatively small area the phytomass of herbaceous communities differs greatly. Soil temperature under herbaceous vegetation canopy mostly depends on soil physical properties, but not on aboveground biomass.

An effective system of Rhododendron yedoense var. poukhanense (H. Lév.) Nakai. regeneration from seedling explant based on the use of thidiazuron (TDZ) for meristem proliferation was presented. In vitro germinated seedlings were used as explants. The duration of seed germination was 24 days. The total germination of the R. yedoense var. poukhanense seeds of was at the level of 77.5 %. The effects of 4-hour TDZ pulse treatment (7.5; 15.0; 30.0 µM) with further transferring to Anderson’s medium (AM) without TDZ and direct cultivation on AM supplemented with 1.0 µM TDZ on the morphogenic potential of seedlings were studied. R. yedoense var. poukhanense regenerants obtained both after pulse treatment and after cultivation on a TDZ-containing medium ware found to require an additional passage on hormone-free AM (AM0) for elongation and an increase in the number of shoots per explant. The highest number of shoots per explant was obtained after elongation with direct cultivation on AM with 1.0 µm TDZ and after 30.0 µm TDZ pulse treatment, on average 9.32 and 10.32, respectively. The maximum percentage of rooted plants (50 %) was obtained under the action of 4-hour pulse treatment with indolyl butyric acid followed by in vitro cultivation on AM0. The presented study demonstrates for the first time the effect of various types of TDZ treatment on the proliferation and development of shoots, and the developed technology made it possible to obtain rooted and acclimatized microshoots induced by TDZ pulse treatment. As a result, R. yedoense var. poukhanense was included in the in vitro collection for conservation and propagation for further practical use.