Diversity of phytophagous beetles (Coleoptera: Chrysomeloidea,Curculionoidea) in steppe communities in the forest-steppe of the High Trans-Volga region

A total of 551 species from 10 families of phytophagous beetles (superfamilies Chrysomeloidea and Curculionoidea) have been recorded in the steppe communities of the High Trans-Volga forest-steppe zone, 62% of which belong to the steppe landscape-geographic complex. The vast majority of the species belong to three families: Curculionidae (254 species; 46%), Chrysomelidae (186 species; 34%), and Apionidae (51 species; 9%). The regional steppe fauna has a complex arealogical structure combining the Western Scythian and Sarmatian elements, as well as relict species of the Angarian origin and some Eastern European ones. The highest diversity of phytophagous beetles is observed in the zonal meadow steppe communities (299 species; 54%). The most specific are the petrophilous steppe complexes which also include the greatest number of relict forms. Xerophilous Kazakhstan- Turanian species are mostly concentrated in the saline steppe communities of the southernmost forest-steppe zone. The species diversity is also high (249 species) in the open ruderal communities dominated by species characteristic of the pioneer stages of the steppe successions. Some steppe reservations include over 50% of the entire regional fauna of phytophagous beetles. The species diversity in the steppe localities decreases northward due to a gradual decrease in the number and proportion of the Scythian species: from 55% in the middle of the foreststeppe zone to 36% near its northern boundary. The species diversity of the slope communities in the forest-steppe zone is at least not lower than that in the similar areas of the steppe zone. The ratio of the number of Curculionoidea species to that of plant species is very high, reaching about 3: 4 in the model steppe localities of the High Trans-Volga forest-steppes, as compared to 1: 2 in the zonal steppe communities (according to the published data). The data considered confirm the significance of the forest-steppe zone as an important biodiversity center in the East European Plain and as a reservation of relicts of different origins.     

Soil-moisture conditions indicated by field-layer plants help identify vulnerable forests in the forest-steppe of semi-arid Southern Siberia

High variability in soil-moisture conditions is typical for semi-arid forest-steppe ecosystems where precipitation varies greatly over time. Plant species that inhabit these environments integrate responses to broadly fluctuating wetness conditions. Indirect assessment of contrasting habitat wetness based on plant indicator values, species frequency, and species coverage was carried out in two sites representing the larch (Larix sibirica) and pine (Pinus sylvestris) forest-steppe communities. For the larch forest-steppe, we found that plant community composition and spatial structure depended strongly on wetness. In addition, we found that the vegetation was clearly differentiated into forest stands and steppe communities, depending on the slope aspect. There was also a strong correlation between dissimilarities of species composition and differences in habitat wetness revealed in the larch forest-steppe. In contrast, soil properties, such as gravel and stone content were found to be a key factor in the spatial distribution of plant species composition in the pine-forest-steppe communities. Indirect assessment of moisture conditions in the forest-steppe habitats, based on the field-layer plant species, was found to be preferable for indicating soil water deficits in the forest. Furthermore, as long-term observational data is often lacking, indirect assessment of the forest-steppe vegetation provides an opportunity to identify vulnerable forests at the marginal distribution. Based on indirect assessments of soil-moisture conditions, and taking into account differences in potential drought resistance between larch and pine forests, we concluded that increasing aridity will cause the replacement of Siberian larch by Scots pine in the South Siberian forest-steppe landscape. Consequently, in the future it is likely that forest-steppe typological diversity will decrease, and the semi-arid landscape may become more monotonous.     

内蒙古草原植物的生态替代及其对全球变化下草原动态的指示（英）

在内蒙古草原区,从荒漠草原带到森林草原带,沿气候干燥度变化的方向调查了119个草原样地的植被与环境特征,依此定量分析了植被—环境关系。 根据表述环境因子取样质量的环境因子墒值及环境因子与出现频率最高的50个植物种间的平均相互信息,分析了所调查30个环境因子在决定植被组成中的作用优势度。结果表明,气候因子的影响是占绝对优势的,而地形和管理因子的作用是次一级的,或是地区性的。群落的物种组成与其第一优势种关联极好,因而依群落第—优势种识别的植物群落类型是组成和结构相对稳定的群落单位。基于植物种在降水和气温梯度上最适区域的计算及依此在植物降水-气温平面上的直接排序,揭示出广泛的草原植物在气候梯度上的生态替代。这种替代,尤其是包括针茅属(Stipa)植物在内的草原优势植物的替代,导致了针茅草原的生态替代。本研究也定量刻划了内蒙古主要草原植物群落的植被特征,及其在气候、土壤和人为影响梯度上的分布幅度和生态适宜区域。草原植物种和植物群落在气候和放牧梯度上的直接排序提供了气候和土地利用变化后草原植被动态的可能图景。     

Ground-beetle (Coleoptera,Carabidae) assemblages in the forest-steppe of the southern Vitim Plateau

A list of species and the structure of ground beetle assemblages in the forest-steppe of Eravninskaya (= Sosnovoozerskaya) Depression situated in the permafrost area are presented. Ground beetle assemblages dwelling in larch, mixed, and small-leaved forests (intact and after fires), and also in the meadow steppe and waterlogged meadows with varying degrees of humidity were studied. The data obtained demonstrate that the communities examined are intermediate between those revealed in adjacent territories of the Selenga River basin, mid-altitude mountains, and of the northern Transbaikalia. The gentle sauce-shaped relief of Eravninskaya Depression is responsible for the concentric circular distribution of carabid assemblages, occasionally interrupted by forest-steppe fragments in isolated forests and meadow steppes. All the hill slopes surrounding the depression are populated by taiga carabid assemblages, whereas the bottom of the depression is the habitat for meadow-steppe and forest-steppe assemblages.     

Floristic diversity of meadow steppes in the Western Siberian Plain: effects of abiotic site conditions,management and landscape structure

Temperate grasslands have suffered from severe habitat loss and degradation worldwide. In Russia, vast areas of forest-steppe grasslands have been converted to cropland during Soviet times, whilst remaining grasslands were often intensively grazed. Contrastingly, the collapse of the Soviet Union have resulted in a massive reduction in livestock numbers and cessation of management. Albeit relatively large natural grassland areas remained in the Western Siberian Plain, their present condition is poorly studied. We analysed plant species composition, functional structure and richness of grassland communities and tested for the effect of local factors (management, abiotic site conditions) and landscape factors (patch size, proportion of land cover types) on diversity patterns. Abiotic site conditions, mainly soil moisture and salinity, differentiated distinct community types. Overall, species richness was highest in meadow steppe communities with lower soil moisture and salinity. Grazing intensity and litter accumulation due to cessation of management were significant negative related to species richness and shaped the functional structure. At the landscape scale, diversity in meadow steppe grasslands was higher in forest-grassland mosaics and in small remnants isolated in a matrix of cropland. Our findings highlight that meadow steppes suffered massively under the historical habitat loss and high grazing pressure. Small species-rich remnants are evidence of the former extent of meadow steppe habitats in agricultural landscape, but are likely threatened by an extinction debt. Low intense, irregular mowing maintained species-rich meadow steppe in forest- grassland mosaics, but currently such practices are declining.     

Patterns of zonal changes in the spatial structure of Orthopteran communities in the European steppe

Patterns of zonal changes in the species composition, diversity, and community structure of Orthoptera were studied along the latitudinal series of steppe types from meadow to desert steppe in European Russia. The maximum abundance of Orthoptera was recorded in the typical steppe, while the maximum species richness shifted to the southern dry steppe. Changes in the ecological preferences of orthopterans due to aridization are shown by the example of zonal communities. A gradual decline of the forest-steppe orthopteran complex and an increase in the number of semidesert and desert species are demonstrated. The changes in the species composition are accompanied by the intra-landscape shifts of areas with high species diversity. Most species in the meadow steppe occupy mesophytic habitats in depressions. In the typical and dry steppe, the species richness and abundance are restricted to habitats with zonal and xerophytic vegetation. In the desert steppe, the species diversity is the highest in dry habitats, including halophytic ones, where xerophilic and desert species predominate. The diversity and evenness indices increase in the northern and southern ecotones of the steppe zone.     

Springtail (Collembola) communities in floodplains of the taiga zone of the Komi Republic

The species composition and structure of collembolan communities in floodplain soils were analyzed; a total of 65 species were found. The highest springtail species diversity was revealed in soils of birch-aspen forests. Collembolan communities in meadow soils were the most similar to those in the aspen forests of the second and third age classes. Prevalence of edaphic and hemiedaphic species is characteristic of soils of birch-aspen forests.     

Characteristics of zonal distribution of the gamasid mites connected with small mammals and their nests in Western Siberia

Analysis of long-term data on the fauna, landscape distribution, and structure of communities of the gamasid mites (Acari:Parasitiformes:Mesostigmata) connected with small mammals and their nests in the plain part of Western Siberia is carried out. By now, presence of 249 gamasid mite species is established in the territory under study, including 193 free-living and 56 parasitic species. Gamasid mites are represented by the maximal number of species on small mammals and in thers nests in northern forest-steppe (102 and 105 species respectively). Nine parasitic species from two ecological groups (epizoic and nidicolous) were found in all landscape zones of the West Siberian Plain, namely: 1) epizoic species Laelaps clethrionomydis Lange, 1955, Laelaps hilaris C. L. Koch, 1836, and Hyperlaelaps arvalis Zachvatkin, 1948 (obligatory non-exclusive hematophagous); 2) nidicolous species Androlaelaps casalis Berlese, 1887 (obligatory non-exclusive hematophagous), Eulaelaps stabularis C. L. Koch, 1836, Haemogamasus nidiformnes Bregetova, 1955 (facultative hematophagous), Haemnogamnasus ambulans Thorell, 1872 (obligatory non-exclusive hematophagous), Hirstionyssus isabellinus Oudemans, 1913, and Hirstionyssus eusoricis Bregetova, 1956 (obligatory exclusive hematophagous). Last three species demonstrate the mixed type of parasitism. The population of gamasid mites on small mammals is most specific in tundra, southern forest-steppe and steppe; the fauna of gamasid mites in nests is most specific in southern forest-steppe and steppe.     

Über die lage des eurasiatischen Steppengebiets in dem system der pflanzengeographischen gliederung des aussertropischen Eurasiens

Summary The author considers the steppe and forest-steppe areas of Eurasia as a special Eurasiatic steppe region. This region is incorporated into Mediterranean (or Ancient Mediterranean) subdominion of Holarctic dominion. Some botanists (M. G. Popov and others) regard the Eurasiatic steppe region as belonging to the boreal part of the Holarctis, that the author of this article considers to be erroneous. The article includes a list of numerous genera, subgenera etc., the distribution of which is mainly confined in the countries, situated within the Mediterranean subdominion and which are represented by different species in the steppe plant communities of the Eurasiatic steppe region.     

The vegetation of the forest-steppe region of Hustain Nuruu, Mongolia

The vegetation of a forest-steppe region in Hustain Nuruu, Mongolia, was studied by a phytocoenological approach. Eleven plant communities were recognized, comprising four steppe communities, two meadow communities, a tussock grassland, two shrub communities, a scrub community and a woodland community. The botanical and ecological characteristics of the different communities are discussed, with reference to the existing classification of Mongolian plant communities. Analysis of the present data indicates that a refinement or extension of the classification system is desirable, especially concerning the steppe(-related) communities. Discussion of the relative distribution of steppe and forest reveals that in the relatively dry location of Hustain Nuruu grassland and shrubland dominate the natural vegetation (88% of the area). Forest covers ca. 5% of the area, it is limited to sites where ground water is within rooting depth: north slopes above 1400 m (Betula platyphylla woodland) and along erosion gullies (fragmentary Ulmus pumila gallery woodland). Under natural conditions forest cover might reach 12%, but it is speculated that wild ungulates could maintain its extension at a lower level. The importance of forest is greater in forest-steppe regions with higher rainfall, but the factors determining the distribution of grassland and forest are expected to be similar.     

Composition and structure of macrozoobenthos of lakes in different natural zones and subzones of Western Siberia

Limnology - In 2003–2016, the composition and structure of macrozoobenthic communities of 49 lakes in three natural zones (taiga, forest-steppe, and steppe) of Western Siberia were...     

Species composition of mosquitoes (Diptera, Culicidae) and possibility of the West Nile virus natural foci formation in the South of Western Siberia

In 2004 June-July collections of mosquito adults and small mammals were carried out in two areas of Novosibirsk Region (forest-steppe and steppe zones), where the West Nile virus (WNV) was for the first time recorded in birds with different migration status in 2002-2004. Seventeen species of mosquitoes were found; significant changes in their species composition and abundance, as compared with latest faunistic studies made in the sixties-seventies of the last century, are revealed. WNV markers (antigen, RNA) are found in small mammals; highly sensitive to the WNV replication mosquito species are also found. These facts allow supposing a possibility of the formation of stable West Nile virus natural foci in the South of Western Siberia, under conditions of forest-steppe and steppe zones.     

Species composition and landscape-zonal distribution of horseflies (Diptera,Tabanidae) in the territory of Belgorod Province

A list of 30 species of the family Tabanidae recorded in Belgorod Province is provided, and data on the landscape-zonal distribution, typical biotopes, and dates of flight in the region are given for each species. The greatest number of horsefly species (24) was recorded in the southern forest-steppe subzone, and smaller numbers, in the central forest-steppe subzone (18) and the steppe zone (16). Half of the forest and forest-steppe species extend into the steppe zone while some southern species penetrate into the forest-steppe zone. The pattern of horsefly distribution is determined by the biotopic conditions. The boundaries of distribution of individual species do not distinctly correspond to those of the landscape subzones.     

短花针茅荒漠草原土壤微生物群落组成及结构

为详细了解内蒙古短花针茅荒漠草原生态系统中土壤微生物群落组成与结构。对其土壤中微生物的总DNA提取后,采用高通量测序技术对土壤中细菌的16Sr DNA和真菌的ITS基因进行了序列测定,分析了短花针茅荒漠草原土壤中微生物群落结构特征。结果表明,共获得细菌OTUs13711个,真菌OTUs 5929个。物种分类显示,细菌种类隶属于29门57纲111目191科485属,其中优势类群为Gammaproteobacteria和Thermoleophilia,它们的相对丰度分别为32.68%和26.83%。真菌隶属于4门16纲45目78科105属,优势类群为Ascomycota和Basidiomycota,它们的相对丰度分别为35.76%和25.90%。土壤中细菌群落的多样性和丰富度均高于真菌。     

Fast attrition of springtail communities by experimental drought and richness–decomposition relationships across Europe

Soil fauna play a fundamental role on key ecosystem functions like organic matter decomposition, although how local assemblages are responding to climate change and whether these changes may have consequences to ecosystem functioning is less clear. Previous studies have revealed that a continued environmental stress may result in poorer communities by filtering out the most sensitive species. However, these experiments have rarely been applied to climate change factors combining multiyear and multisite standardized field treatments across climatically contrasting regions, which has limited drawing general conclusions. Moreover, other facets of biodiversity, such as functional and phylogenetic diversity, potentially more closely linked to ecosystem functioning, have been largely neglected. Here, we report that the abundance, species richness, phylogenetic diversity, and functional richness of springtails (Subclass Collembola), a major group of fungivores and detritivores, decreased within 4 years of experimental drought across six European shrublands. The loss of phylogenetic and functional richness was higher than expected by the loss of species richness, leading to communities of phylogenetically similar species sharing evolutionary conserved traits. Additionally, despite the great climatic differences among study sites, we found that taxonomic, phylogenetic, and functional richness of springtail communities alone were able to explain up to 30% of the variation in annual decomposition rates. Altogether, our results suggest that the forecasted reductions in precipitation associated with climate change may erode springtail communities and likely other drought‐sensitive soil invertebrates, thereby retarding litter decomposition and nutrient cycling in ecosystems.     

Species richness and zonal features of partial faunas of phytophagous beetles (Coleoptera,Chrysomeloidea, Curculionoidea) on grassy slopes in the east of the Russian Plain and the Cis-Ural Region

Comparative analysis of the fauna of phytophagous beetles (Chrysomeloidea, Curculionoidea) on grassy slopes in the east of the Russian Plain and in the Cis-Ural Region was performed. The species richness, taxonomic and chorological structure, and specificity of 22 partial faunas were assessed along the latitudinal gradient from the taiga to the steppe zone. The slope faunas are shown to have extrazonal features and to function as refuges of rare species. The species richness of slope communities of phytophagous beetles increases 2–3-fold (from 105–174 to 283–303 species) from the taiga to the forest-steppe, largely due to an increase in the number and share of representatives of the steppe landscape-geographic complex. The ratio of the number of species of Curculionidae to that of Chrysomelidae changes from 1: 1 to 1.5: 1.     

Spatial heterogeneity of a ground beetle (Coleoptera,Carabidae) population along a forest-steppe transect: Local level of consideration

Carabid diversity has been studied in the forest-steppe in southern West Siberia along a continuous 180-m transect from the center of a small birch forest outlier through steppe and mesophytic meadows to a single tree. Carabid communities characteristic of open and forest habitats are different. Communities of open habitats are more differentiated than forest ones. The former can be further subdivided into steppe and meadow variants. Some species are generalists, exhibiting no preferences to particular open habitats.     

The steppe insect fauna in the Russian Far East: Myth or reality?

The fauna of Lepidoptera in the forest-steppe zone of southern plains of the Russian Far East is analyzed. The contribution of species with the optimal distribution in the steppe and forest-steppe zones of Eurasia into the above fauna is insignificant; eastern Asian temperate species dominate in the region. The classification analysis of lists of species from local steppe and forest-steppe faunas of both Far-Eastern humid “prairies” and southern Transbaikalian region is performed. In these regions, xerophilous species constitute the essential part of the local fauna. The necessity of revision of the present zoogeographical zoning of the Far East is substantiated.     

Differentiations of determinants for the community compositions of bacteria,fungi, and nitrogen fixers in various steppes

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Zonal types of host-parasite complexes of arthropods and small mammals in the west Siberian Plain

Comparative analysis of the composition, population structure, and landscape distribution of small mammals and associated parasitic arthropods was performed for the plain part of West Siberia. Four main zonal complexes were distinguished, corresponding to different landscape zones or subzones: tundra, forest, forest-steppe (the northern forest-steppe subzone), and steppe (the southern forest-steppe subzone and steppes). The parasite specificity of each complex is defined by different systematic and ecological groups of arthropods: the tundra complex is defined by epizoic gamasid mites (Acari: Parasitiformes: Mesostigmata), the forest and forest-steppe complexes are defined by ticks (Acari: Parasitiformes: Ixodides) and fleas (Insecta: Siphonaptera), and the steppe complex is defined by fleas and nidicolous gamasid mites.