Specific Features of the Formation of Animal Species Communities in Technogenic and Urbanized Landscapes

The formation of the species composition and specific functional, physiological, and phenotypic features of populations in technogenic and urbanized areas was studied by analyzing murine rodents, amphibians, and soil invertebrates. It is shown that, against the background of decreasing total abundance and biomass of animals, their formerly continuous ranges become mosaic, with the locally increasing animal density and heterogeneity and specific population dynamics. Species diversity decreases; however, species alien to the natural ecosystems of the given territory appear. Changes in the strategies of reproduction and food resource use were revealed in the species communities of small mammals and amphibians.     

Analysis of rodent populations in technogenically transformed areas (with reference to <Emphasis Type=Italic>Apodemus</Emphasis> (<Emphasis Type=Italic>S.</Emphasis>) <Emphasis Type=Italic>uralensis</Emphasis> from the EURT zone)

It is shown that the response of rodent populations to acute and chronic irradiation depends on its functional structure, i.e., on specific features of animals with two alternative types of ontogenetic development. Upon acute irradiation, sexually immature young of the year (animals with the second type of ontogeny) are most radioresistant. Exposure to chronic irradiation, as in the zone of the Eastern Ural Radioactive Trace (EURT), leads to an increase in the proportion of mature young of the year (animals with the first type of ontogeny), which are the most radiosensitive part of the population. The abundance and fecundity of mice in the impact zone are consistently higher than in the background zone, which improves the adaptive potential of the population. The role of species ecological specialization and configuration of the contaminated zone in the formation of migrant rodent population is emphasized. It is concluded that a high migration activity allows the pigmy wood mouse (a radiosensitive species) to avoid long-term radiation exposure.     

Mechanisms Providing for Species Coexistence in the Herb-Dwarf Shrub Layer of a Southern Taiga Birch Forest

Individual species coexisting in the herb-dwarf shrub layer of a mature southern taiga birch forest were studied with respect to their limitation by different environmental resources and differences in the time or localization of the intensive utilization of deficient resources. The results made it possible to estimate the significance of different mechanisms of species coexistence in multispecific communities for herbaceous and dwarf shrub species of the forest phytocenosis studied.     

New Approaches to the Assessment of Structural Organization of Communities in Springtails (Hexapoda: Collembola)

Trends in the diversity of structural organization of soil animal communities are analyzed using an example of the taxocenes of springtails, small soil arthropods. Different methods for describing the structure of communities are considered. On the basis of parameters characterizing specialization and stability of communities, several patterns of their organization in springtails are distinguished. It is shown that the new approach offers new opportunities in forecasting community dynamics under the effects of natural and anthropogenic factors.     

Special features of fish species composition and community structure in small rivers of the Udmurt Republic

The composition and species richness of ichthyofauna have been studied in 36 stretches of small rivers in the Udmurt Republic to estimate the dependence of species richness on the distance from the river source and the level and type of anthropogenic load. Some specific features of modification of the fish community structure under the influence of agriculture, urbanization, and industry (oil production) have been revealed. Basic trends in the change of dominant complexes of fish species with an increase in the distance from the river source are described for small rivers flowing in different natural and anthropogenic landscapes of the Udmurt Republic.     

Structure of the communities of small mammals (micromammalia) in forests on western slopes of the Northern Urals

Long-term data on the species composition and ratio of insectivores and rodents in forest ecosystems of the western macroslope of the Northern Urals are considered. It is shown that the micromammalian communities of mountain forests are characterized by higher total abundance and polydominance and comprise greater numbers of common species than the communities of taiga forests in neighboring regions of the Russian Plain. Hence, the mountain-forest communities of small mammals have high indices of species diversity and uniformity.Translated from Ekologiya, No. 2, 2005, pp. 138–145.Original Russian Text Copyright © 2005 by Bobretsov, Lukyanova, Poroshin.     

Effects of anthropogenic disturbances on vegetation diversity and structure: a case study in the remnant forests surrounding the village ecosystems of Tripura,Northeast India

The types, frequency, and intensity of human interference with forests markedly affect the vegetation dynamics. Assessment of the impact of anthropogenic disturbances on forest diversity and structure is one of the central issues related to human behaviour and forest ecosystems and management. Both species diversity and density are very sensitive to local anthropogenic disturbance, which can be reduced depending on land-use systems. We used 10 line transects of 500 × 10 m to record and measure all plants ≥10 cm girth in some of the remaining forests surrounding villages in Tripura, Northeast India. To predict the effects of anthropogenic pressure on species richness and forest structure, we recorded and scored all ongoing disturbances in all transects of the forests. Although our study did not show any significant effects on the mean number of species, all diversity indices were significantly affected by disturbance. Total stem density (F = 128.60, p < 0.0001) and basal area (F = 65.30, p < 0.0001) of the forest stands were significantly affected by disturbance. Disturbance significantly (F = 84.81, p < 0.0001) impacts the abundance of mature voluminous trees removed by extensive illegal logging. Further, stem density at the middle (F = 10.01, p < 0.05) and upper (F = 131.70, p < 0.0001) canopy stories was also reduced by high disturbance intensity. The present analysis will be useful to policy-makers and planners for implementation of sustainable forest management at both the local and regional scale.     

The narrow-skulled vole (<Emphasis Type="Italic">Microtus gregalis</Emphasis> Pall.) in the dynamics of zonal rodent communities of northern Eurasia

On the basis of abundant fossil and subfossil bone remains, the ecological and faunal role of the narrow-skulled vole in zonal rodent communities of northern Eurasia is analyzed over the period from the Late Pleistocene to the present time. Special attention is given to the correlated dynamics of relative abundance of Microtus gregalis and other rodent species in the course of transition from one zonal type to another and to specific features of this correlation in the southern, middle, and northern parts of the species range. It is shown that distinctive dimensional and morphotypic features of the two currently existing subspecies, Microtus gregalis major Ogn. and M. g. gregalis Pall., are the product of concordant development of the species and environmental conditions in the past 3000–4000 years (transition from the Holocene optimum to the present-day climate and state of the natural environment). Published in Russian in Ekologiya, 2007, Vol. 38, No. 2, pp. 117–123. The article was translated by the authors.     

Experience in quantitative analysis of floristic structure and diversity in Samarskaya Luka

Quantitative methods have been applied to the study of floristic structure and diversity in Samarskaya Luka. The results show that Samarskaya Luka is a floristically heterogeneous area in which six elementary floras can be distinguished. This area has been assessed as a floristically autonomous formation, and its floristic representativeness was estimated.     

Carabids in a Spring Wheat Agrocenosis to the South of Sverdlovsk Oblast and the Effect of Insecticide Treatment on Their Populations

Species composition, community structure, and seasonal population dynamics of carabids in spring wheat fields were studied in the vicinity of Yekaterinburg. In addition, the effects of crop treatment with the pyrethroid insecticide Decis on carabid populations was analyzed. The results showed that the numbers, species diversity, and the prevalence of certain trophic groups of carabids changed during the season. After the treatment of small areas with Decis, the number of carabids in catches decreased for a short period of time. During the second and third weeks after the treatment, the numbers of carabids increased above the control level. The structural rearrangement of the carabid community was observed in the areas treated with the insecticide.     

Structural-functional organization of lower vegetation layers in tree communities of the upper timberline ecotone in the Polar Urals

Typologically identical (dwarf birch-herb-dwarf shrub-moss) open and closed larch forests growing on the same altitudinal transect have proved to differ in the structural-functional organization of lower vegetation layers. Coverage, general species composition, and species richness of the herb-dwarf shrub layer are higher in the open forest than in the closed forest. Correlations between individual species of vascular plants weaken upon transition from the open to the closed forest. Conversely, the coverage of the lichen-moss layer increases in the closed forest, which contributes to its role as a factor of selection of vascular plant species against the background of the prevailing influence of the tree layer.     

Response of lithophilic zoobenthos to changes in the granulometric composition of grounds in the metarithral zone of a small river in the foothills of southwestern kamchatka

Data on the species composition, abundance, and biomass of macrozoobenthos in the rapids of a small river flowing in the foothills of the southwestern Kamchatka Peninsula are considered along with the results of quantitative analysis of structural rearrangements in the lithophilic community under the effects of changes in the granulometric composition of bottom sediments. Groups of lithophilic and pelophilic invertebrates typical of the metarithral of such rivers (e.g., chironomids of subfamilies Diamesinae and Prodiamesinae) are identified.Translated from Ekologiya, No. 2, 2005, pp. 120–125.Original Russian Text Copyright © 2005 by Leman, Chebanova.     

Comparative Analysis of Foraging Behavior in Aquatic and Semiaquatic Spiders of the Genera Argyroneta,Dolomedes, Pirata,and Pardosa

A group of sympatric aquatic and semiaquatic spiders inhabiting Western Siberia (Argyroneta, Dolomedes, Pirata, and Pardosa) has been studied with respect to specific ethological features. The results provide a basis for the conclusion that these spiders differ in a number of behavioral adaptations related to prey catching and the use of common biotopic space. Experiments with the predator–prey system have shown that spiders have different effects on the abundance of bloodsucking mosquito larvae and on the age and genetic structure (at the chromosomal level) of their populations. The functional role of spiders in communities is discussed.     

中国西部开发防灾减灾建设综合管理战略初论——谈西部生态建设山川秀美评价

中国西部开发战略作为迈向21世纪的壮举,已引发各界的关注。但如何在西部大开发中实施防灾减灾战略,即如何利用科技减灾为西部生态环境建设作贡献则成为全部问题的焦点。本文指出,应崇尚一种实事求是的科学精神及战略观念,靠科学评估,靠灾害风险分析,靠适度的生态环境政策,确保21世纪西部开发的规划、设计、建设各个环节中充分考虑防灾减灾这一关系西部可持续发展的关键要素。     

Population structure and dynamics of Monotarsobius curtipes (Myriapoda, Chilopoda) at the northern periphery of the species range

Studies on the population structure and dynamics of the stone centipede Monotarsobius curtipes C. Koch in soils of the northern Kola Peninsula have shown that, with respect to abundance and biomass, this species is a dominant of the soil macrofauna and, in particular, of the trophic group of zoophages. Life in high northern latitudes does not disturb the sex and age structure of populations but limits the reproductive activity of these centipedes. Specific biological features of M. curtipes at the northern periphery of its range include the absence of repeated breeding, completion of several developmental (age) stages within a short growing season, and long ontogeny involving several winterings.     

Changes in the structure of chortobiont invertebrate community exposed to emissions from a copper smelter

The aboveground phytomass of meadow plants and the density of chortobiont invertebrates in secondary upland meadows were estimated using a biocenometer in three areas differing in the level of pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) in 2006 and 2007. As the smelter is approached, the total amount of phytomass (dry weight) decreases by a factor of 1.3–1.9, with the proportion of grasses reaching 100%; the total abundance of invertebrates increases two-to threefold due to sucking phytophages, which account for up to 80% of the invertebrate community. The abundance of gnawing phytophages near the smelter is reduced, with some taxa entirely missing (e.g., mollusks and phalangiid harvestmen). Rearrangements in chortobiont community structure are attributable to changes in the physiological state of plants and in the species diversity and architecture of the herbaceous layer, with consequent modification of hydrothermal conditions in it, as well as by the direct toxic effect of heavy metals.