Nº 4 (2024)

Soil macrofauna of three microstations was compared between background and contaminated areas: within decaying trunks of deciduous trees (linden, aspen) in the final stages of decomposition, beneath the trunks and outside the influence of the trunks (standard soil samples). The composition of macrofauna was analysed at two levels: (i) supraspecific taxa and (ii) species for several taxocenes (earthworms, centipedes, arachnids, ground beetles, click beetles, and mollusks). The study was conducted in the spruce-fir forests of the southern taiga, in the area affected by emissions from the Middle Ural Copper Smelter. At the level of supraspecific taxa, the composition of macrofauna differs little between decaying trunks and standard soil samples. At the species level, the difference between microsites depends on the specific taxocene: the species composition within decaying trunks either almost coincides with that of standard samples (mollusks), or is more specialized (click beetles), or is more diverse (centipedes, arachnids, ground beetles), or is reduced due to the loss of a specific ecological group (earthworms). The ordination of microsites based on the general list of species for the investigated taxocenes aligns with the ordination based on the composition of macrofauna at the supraspecific level. The total density and abundance of most groups of soil macrofauna are higher in trunks than in standard samples. In the background area, the difference is especially pronounced (2—6 times) for earthworms, harvestmen, lithobiids, herbivorous heteroptera, ground beetles, and chironomid larvae. In contaminated areas, the difference is even more substantial: for earthworms it is 70 times, for mollusks — 30 times, for heteroptera — 10 times, for lepidopteran larvae — 7 times, for spiders — 5 times, for diplopods — 4 times. The predominant habitation of soil macrofauna in decaying trunks within contaminated area may be associated with a significantly lower concentrations of potentially toxic metals in decomposing wood compared to forest litter: for Pb, the difference is 85 times, for Fe — 77 times, for Cu — 25 times, for Cd — 2.6 times, for Zn — 1.7 times. Thus, the negative impacts of pollution on soil macrofauna are less pronounced in decaying tree trunks than in standard soil samples.

The Hyrcanian forests are a relict woodland remaining since the Tertiary period, located in Iran and southeastern Azerbaijan. No publications devoted to earthworms in the Azerbaijani part of the Hyrcanian forests have been found. The purpose of the work is to study the fauna, population structure and biotopic distribution of earthworms in natural and disturbed biogeocenoses of lowland Hyrcanian forests of Azerbaijan. The material was collected in the Hyrcanian National Park. When processing the data, occurrence, average and relative abundance were used. Indices of dominance, biodiversity, evenness and synecological characteristics’ coefficients of variation were calculated. The core of the earthworm fauna of the Hyrcanian forests is formed by Lumbricidae with a Transcaucasian and Turanian distribution, as well as species of Mediterranean origin. In forest areas in which the tree layer edificator is chestnut oak, taxocenes are characterized by a stable species composition, small values of total abundance and significant variability in synecological indices. The structure of the meadow taxocenes depends on the localisation of the biogeocenosis: in the areas surrounded by oak forests, it is formed by forest species; in the fringe communities, an influx of the steppe zone inhabitants and a sharp increase in the total number of earthworms are noted; a larger percentage of the total number is made up of soil lumbricids. In the meadow taxocenes, litter species are not recorded; Mediterranean species are rare and occur in small numbers, but cosmopolitan species are present. In the secondary forest biogeocenoses, compared to meadow biogeocenoses, in the chorological structure of earthworm taxocenes, the representation of Mediterranean and confirmed cosmopolitan taxa tends to increase, while among morpho-ecological groups there is a trend for an increased representation of litter species. The structure of hornbeam, pecan and black walnut taxocenes is balanced and diverse, includes rare species, and has a smaller representation of autochthonous faunal elements.

The taiga and forest-steppe ecosystems of Western Siberia are subject to significant climatic and anthropogenic transformations. Understanding the relationship between the number of earthworms, which play an important role in forest communities, and environmental conditions can be used in monitoring the state of ecosystems. The goal of the work was to identify the relationship between the numbers of earthworms in communities of the forest-steppe and taiga zones in the southeast of Western Siberia and the landscape features, climatic parameters of the environment, as well as the timing of material collection during the warm season. The analysis included data on earthworm abundance from 62 habitats. Modeling was conducted by factor analysis of mixed data (FAMD). To identify their correlation with the numbers of earthworms, quantitative data on soil types and vegetation, physicochemical soil characteristics, climatic parameters and categorical data on orographic and hydrothermal zoning, geobotanical zoning on soil types and vegetation, and timing of material collection were considered. In all cases, the observed dispersion was better explained by the hydrothermic zoning of the territory, climatic and soil conditions and the resulting patterns were more indicative of the number of morphoecological groups, rather than individual species of earthworms. The assumption was confirmed that dependence on parameters affecting soil moisture was more characteristic to the burrowing group of worms; in other cases, there was no strong observable connection. Thus, it follows that in the southern taiga and the forest-steppe of the southeast of Western Siberia, the observed abundance in communities will depend to a lesser extent on the month of collection of material than is generally believed for temperate zone ecosystems.

For the first time, the taxonomic composition and seasonal distribution of herpetobiont invertebrates were studied in plant communities dominated by Siberian elm in Western Transbaikalia in 2009, 2018—2019 and 2021. The study encompassed arachnids (spiders, harvestmen) and beetles (ground beetles, leaf beetles, darkling beetles, weevils) who were collected in soil traps. Overall, 76 species from 2 classes, 5 orders, 16 families were identified. Most invertebrates are characterised by summer and summer-autumn activity periods. In elm forests, conditions allow for the existence of relict insect species populations: Ambrostoma quadriimpressum (Coleoptera, Chrysomelidae), Tomapoderus ruficollis (Coleoptera, Attelabidae), Pentatoma metallifera (Heteroptera, Pentatomidae). Among ground beetles Carabus glyptopterus, included in the Red Book of the Republic of Buryatia was identified.

Intact forest areas (IFA) are an important part of valuable natural areas. They represent large areas of wilderness within the forest zone and perform protective, climate-regulating functions, reduce the concentration of greenhouse gases, maintain biodiversity and play an important role in the carbon cycle. In the Russia’s Far East, the processes of carbon cycling have so far been insufficiently studied, especially within forest river ecosystems. One of the first stages of research to understand the patterns of transformation and transport of carbon in river ecosystems should be the study of the species and trophic structure of river communities, the identification of organisms – primary destructors of organic matter and algorithms for the sequential processing of autochthonous and allochthonous organic matter produced in river and adjacent terrestrial ecosystems. The paper presents the results of an analysis of the structure of benthic communities of 22 waterways (44 habitats) located in forested and deforested areas, and identifies 5 types of communities (with 10 subtypes), corresponding to the longitudinal zones of the river and the main parameters determining the architecture and “economy” of the river ecosystem in in accordance with the concept of river continuum. It has been established that the main primary destructor of leaf litter in the upper reaches of rivers in the south of the Russian Far East are gammarid crustaceans. It has been shown that forest cover disturbance leads to changes in the fundamental structure of river communities and leads to irreversible changes in the ecosystem.