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Rotatoria and Crustacea in the lower stream of the Turga river (Transbaikalian Region). – Afonina E. Yu. – Hydrological features, hydrochemical regime, and anthropogenic influence are shown to affect the specific composition, structure and time dynamics of the river zooplankton. The biogenic saturation, low current rate, and biotope variety of the artificial river mouth favor the formation of a limnophilous complex of Crustacea. A rotifer community develops in the conditions of high water exchange of the drainage channel.
Key words: zooplankton, abundance, biomass, spatial distribution, natural and artificial channel.
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Water masses and zooplankton in a tributary of the Rybinsk Reservoir in its backwater zone. – Bolotov S. E., Krylov A. V., Zvetkov A. I., Sokolova E. A., and Poddubnyi S. A. – In 2008, transitive (gradiental) and stable sites were resolved in the Rybinsk reservoir' tributary and its backwater zone by water conductivity. The highest BOD5 (biochemical oxygen demand) values and the maximum zooplankton abundance, within the backwater zone as well as in comparison with the neighboring systems (the river and reservoir), were observed within the transitive site, where a marginal effect appeared.
Key words: small river, reservoir, zooplankton, abundance, biomass, number of species.
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Comparative analysis of ciliate communities (Ciliophora) in brackish waterbodies of two tectonic heights in the Volga region. – Bykova S. V. and Zharikov V. V. – A comparative analysis of the specific composition, quantitative and structural parameters of ciliate communities in highly mineralized waterbodies of the Middle and Lower Volga basin was carried out. The specific composition, specific and trophic structure of a ciliate community have been shown to depend not only on the geographical proximity of waterbodies but also on the hydrological and hydrochemical conditions therein. These conditions are caused by the lymnogenetic stages of «blue» lakes, beginning from «young» waterbodies (cold-water ones, with high water exchange and high transparency) to «old» waterbodies (stratified ones, with freshened water). The quantity of species, the abundance and biomass of ciliate communities in small brackish waterbodies have been revealed to be lower than in freshwater ones.
Key words: ciliates, diversity, waterbodies, anaerobic conditions.
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Classification and structure of bird communities in the Aldan upland region. – Vartapetov L. G., Isaev A. P., Larionov A. G., and Egorov N. N. – On the basis of long-term accounts the bird communities of one of least investigated regions of Yakutia – Aldan upland region is studied. The made classification and spatially-typological structure of bird communities allowed to establish, that for their formation are most significant altitude belting and forest square. Less significant factors – presence of reservoirs, marshiness, development of a shrubby circle and building-up. Are least significant level of altitudes in the limits of separate altitude belts, species composition of vegetative formations and influence of fires. The species richness and density of bird communities steadily decrease with increasing of local altitudes. Only in cedar bushes with sites of thin forests total abundance of birds more than in more low located landscapes, at the expense of increase in number of shrubby birds.
Key words: bird communities, Aldan upland region, altitude belting.
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Population estimation of larine birds (Laridae) in lagoons of the Middle Caspian Sea west coast. – Vilkov Ev. V. – The paper gives generalized data obtained along two key routes within the area of the Turali and Sulak lagoons in Daghestan (the Middle Caspian Sea west coast) during 1995 – 2009. 12 larine species of the 19 ones found in the lagoons have been resolved as model taxa according to the area of their habitat, ecological preference differences, and the relatively stable number on flyways. The model species were divided into 3 groups by abundance, namely, dominant, subdominant, and collaterally subordinate, which make the core of the Laridae population in the surveyed area. Our estimation of the regularly migrating Laridae populations and our study of the causes of long-term fluctuations of their number were conducted by long observations on heavily travelled flyways. Of the 12 model taxa, 8 ones have experienced a decline in numbers, while the residual 4 have preserved or even increased their population. The key regulating factors are such as the anthropogenic, forage, hydroclimatic and weather ones. The data of our observation permit one to hypothesize that the number of regular migrants at the nodal points of their flyways reflects the real dynamics of the transfrontier Laridae populations because populations migrate rather than species. This fact can serve a foundation for development of a unified strategy for conservation of the rare and scanty Laridae species in Eurasia.
Key words: Laridae, regular migrants, lagoons, Daghestan.
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Variability of the population structure of meadow-glade ecological-coenotic groups in the conditions of the succession type of dynamics of a wood biogeocenose. – Dubrovnaja S. A. and Volkov O. I. – The species of the meadow-glade ecologo-coenotic group in the forest biogeocenosis are presented in phytocenoses at various succession stages. Preservation of the species on the occupied space under consecutively changing phytocenoses is provided due to the plasticity of both overground and underground vegetative plant organs. Reorganization of both overground and underground vegetative organs determines a peculiarity of the demographic processes and the variability of the ontogenetic structure of a cenopopulation.
Key words: Fragaria vesca, Hypericum perforatum, population structure, morphological variability.
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Wheat shoots resistance to the influence of copper and formaldehyde in a wide dose range. – Erofeeva E. A. – The highest concentrations of copper and formaldehyde used by us induced a significant monotonic disturbance in wheat shoots. It was expressed in decreasing of the pigment level and growth, an increase in the lipid peroxidation intensity. The dose dependences of all the parameters were non-monotonic at lower concentrations of both toxicants, having two and more phases. The lipid peroxidation intensity and the shoot resistance to osmotic shock were the most changeable parameters.
Key words: Triticum aestivum, copper, formaldehyde, pigments, lipid peroxidation, osmotic shock, non-monotonic dependence.
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Condition dynamics of the beaver food base in their settlements after several settling cycles. – Zavyalov N. A. – The condition of the food base of beavers (Castor fiber Linnaeus, 1758) after several settling-neglecting cycles is analyzed with three settlements on small rivers of the Novgorod region as examples. It is shown that at different structures of the forest stand and different extent of its destruction, all settlements feature the total absence of forage in the forest stand: asp is absent while birch is presented as large trees, demanding big efforts for their felling and cutting. In the rising forest and underbrush, the lack of asp is noted whereas willow and birch are numerous but presented as thin boles non-uniformly distributed in space. In the neglected settlements, poorly-eaten breeds are plentiful, which can demand additional energy expenses from beavers to find fodder plants. It is supposed that on small rivers in the southern taiga, in the conditions of beavers' transformed habitats, beavers will exist with abundance much smaller of the highest possible one, determined by the rate of forage restoration at a decreasing quality of the habitats.
Key words: Castor fiber, environment-forming activity, population dynamics, habitats, feedback.
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Fleas (Siphonaptera) on small mammals in the Saratov Trans-Volga region. – Knyazeva T. V., Porshakov A. M., Kuznetsov A. A., Mokrousova T. V., and Matrosov A. N. – The modern fauna of fleas (Siphonaptera) on small mammals from intrazonal biotopes in the Saratov Trans-Volga region was identified. Qualitative and quantitative alterations of the ectoparasite specific composition were analyzed in comparison with those registered in the 1960s and 1970s. Faunistic clusters of small mammals and their ectoparasites according to the landscape and geographical zones of the Trans-Volga region are presented.
Key words: flea fauna, small mammals, Saratov Trans-Volga region, landscape and geographical zones.
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Anthropogenic transformation of soils and vegetation as a result of afforestation in deserted steppes. – Novikova N. M., Novikova A. F., and Konyushkova M. V. – The modern state of vegetation and soils of a saline soil complex at sites with tree failures in the «Volgograd – Elista – Cherkessk» state forest belt is compared with the data obtained before the afforestation (1950 vs. 2006 – 2008). The vegetation and soils are shown to have considerably changed. At the sites with tree failures on saline agrosoils, grassy plant communities similar to natural ones have appeared. Under the artificial forests, antropogenically-modified soils have formed, completely dissimilar to those which they have originated from. The initial strongly saline soils with chloride-sulfate salinity have been transformed into slightly saline agrosoils with sodium-sulfate salinity, with an increased alkalinity in the middle part of the soil profile, and with a completely dealkalinized arable layer.
Key words: agricultural amelioration, plant communities, species richness, overground phytomass, salinity of soils, Ergeny, Kalmykia.
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Place of aspen (Populus tremula Linnaeus, 1753) in the succession processes in mountain forests of the Southern Volga Upland. – Khayrov I. Kh. and Kozachanko M. A. – The role of aspen in the succession processes in upland forests of the Southern Volga Upland was investigated by analysis of forest management materials and route descriptions of forest communities. The degree of aspen involvement in various layers of the forest communities was estimated. Factors influencing the presence of aspen in forest plant communities have been established.
Key words: aspen forests, forest composition, phytocenosis level, moisture conditions, Saratov region.
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