Home – Home – Jornals – Contemporary Problems of Ecology 2007 number 4

A new experiment of the Hövsgöl Drilling Project was carried out in Lake Hövsgöl in 2004, as part of the international program of scientific drilling in the Baikal Rift. The reported data include a preliminary description of the recovered lake sediments (HDP-04 core), with their compositions and physical properties, and a tentative age-depth model based on the paleomagnetic polarity scale. This is the first evidence that the lithology of sediments deposited for the past ~1 Myr records periodic alternation of carbonate-free diatomaceous mud and carbonate-bearing silty clay.
The diatom intervals in the record are interpreted as corresponding to interglacials by analogy with the periodicity known since the Last Glacial. The core bears signature of at least nine lithological change events. The sediment lithology records extremely low stand of Paleo-Hövsgöl (shallow-water facies produced by erosion of older sediments at the point where the today's lake reaches a depth of 240 m). Correlation of the HDP-04 core data with reflection profiling evidence confirms the presence of quite a large gap in the Pleistocene sedimentary record from the Hövsgöl rift basin.
The discovery of alternating carbonate-rich/carbonate-free cycles and evidence for sudden lake level changes impart special importance to the Hövsgöl archive: It can provide a deeper insight into the regional water budget and humidity history than it has been so far possible for the Middle and Late Pleistocene.

Results of study of pore waters of bottom sediments from different Baikal basins are presented. The most typical ion distribution patterns reflecting the Baikal sediment diagenesis are given. We have established that in areas with regular sedimentation, in the absence of faults and inflows, the sediment pore waters of three lake basins inherit the chemical composition of the Baikal water, which is stable in time and space. Changes in pore water composition mark general natural anomalies, such as the presence of active faults, tectonic movements, and inflows along permeable zones. In areas with the subsurface occurrence of gas hydrates, thorough long-term research has revealed an anomalous composition of pore waters. It has been established that the anomalies are caused by a discharge of deep-level mud-volcanic fluids. The ejected mud-volcanic waters differ from each other in mineralization, ion composition, and sources, which determines the difference in hydrate formation and the composition of gas hydrates.

Wall-rock metasomatites of the Kara gold deposit, a high-temperature medium-depth pneumatolytic-hydrothermal formation, have been studied. Gold mineralization is associated with the intrusion of granitoids of the Kara-Chacha massif (J₃) and dikes of alkaline rocks (J₃-K₁), which include hybrid porphyries,

Regional ore-magmatic systems (OMS's) and metallogenic gold-silver belts in northeastern Asia are considered, with emphasis placed on their relationships owing to the effect of geodynamic settings and underlying and host rock sequences on the localization of gold and silver deposits of different types. Particular types of lithologic assemblages with specific mineralogical and geochemical features are persistent throughout the metallogenic belts, controlled by regional noble-metal OMS's. Regional OMS's with one-, two-, and multilevel local OMS's producing different types of noble-metal mineralization are described. The problem of mineral typomorphism in metallogenic analysis has been first raised. This analysis permits one to recognize indicators of ore formation (a particular genetic type of deposits, their formation and denudation levels), sources of ore-forming fluids, regional specific geochemistry and its relationship with magmatism. Regular presence of platinum in gold-bearing metallogenic zones is shown.

The face effect was observed in all individual compounds with beryl structure having grown at a rate of 1-8 unit cells a second, with spontaneous crystallization in the system beryl (or cordierite)-Mg,Ca/Cl,F-impurity, where impurities are Ti, V, Cr and/or Fe oxides. By

In the section of Agaleevskaya BH-4 drilled in the lower reaches of the Angara River, Vendian and Baikalian sediment sequences have been recognized within Neoproterozoic strata. The Vendian sequence is formed by terrigenous-carbonate deposits of the Tetere, Soba, and Katanga Formations of the Danilovo Horizon, referred to as the Upper Vendian Nemakit-Daldyn Stage, as well as by terrigenous deposits of the Taseeva Group. The Baikalian Horizon is composed of the Brus Formation, earlier recognized only on the Chadobets uplift, and is separated from the Vendian deposits by a stratigraphic gap. In the Brus Formation, a microfossil complex similar to earlier described biotas of the Siberian Baikalian strata was found. The underlying deposits of the Terina Formation contain microfossils lacking below the basement of the Lakhanda Horizon (Neoproterozoic).

The Berriasian-Barremian biostratigraphy based on spores and pollen of terrestrial plants found in sections from northern Siberia shows a succession of eight units. The ages of the units are proved by calibration against the Boreal zonal standard and their stratigraphic position is controlled by faunal and dinocyst records. The sections of the study are depth-stacked over one another, with partial overlap, and include several isochronous levels marked by the same palynological features. The levels are defined by changes in the taxonomic composition of spore-pollen assemblages found in the sections and recognized using published evidence from northern Siberia. Most of the identified boundaries of the palynostratigraphic units provide a good potential for northern Siberian regional correlation.

Experimental studies of energy balance in low-field seismic stimulation of oil recovery show that producing formations can change their properties at the expense of internal energy activated by the applied seismic load. The suggested stimulation mechanism is based on the effect of low-amplitude waves on plastic strain in the formation as the latter becomes moved off its thermodynamic equilibrium by the production process. The suggested model explains many effects known from experiments which result from interplay of different physical processes.

We discuss approaches to mapping lateral apparent conductivity variations at different periods from magnetic observatory data using multipoint transfer operators as nonlocal functions of the EM response. The multipoint operators provide correlation of three magnetic field components recorded at all observatories. The inversion procedure was applied to S_qobservatory data for 1964-68 and records of 30 magnetic storms for 1957-2001. To obtain lateral conductivity patterns, data on diurnal S_qvariations and global magnetic storms were processed with the spherical harmonic analysis. The same data were used to estimate the coefficients of first harmonics in the SH series of diurnal lateral variations of Earth's apparent conductivity.

A priority evolution-ecological concept of the development of plant protection is developed. This concept combines the achievements of evolution ecology in the area of the indices of evolution-ecological strategy and tactics of the life cycles of biological species against hazardous organisms (phytopathogens, phytophagues, weeds), the ideas of the beginnings, course and attenuation of epiphytotic process, ecological classification of hazardous organisms allowing one, relying upon the system agrotechnical method, to create the conditions which would be favourable for the functioning of under- and overground parts of plants and unfavourable for reproduction, survival and trophic links of hazardous organisms in agricultural ecosystems; irrational application of pesticides may thus be rejected or reduced substantially.

Plant waste is accumulated and decomposed between tightly growing shoots of polster plants. This allows polster plants to compensate for the deficiency in nutrients in case of their lack in the habitats. Due to this feature and favourable hydrothermal regime inside the

The modern agroecological situation with typical black soil in the foothills of the Central Caucasus is considered. The data allowing one to evaluate the state of typical black soil were obtained experimentally. A procedure based on qualitative and quantitative changes in plough-land, in comparison with virgin lands was approved. The results confirmed morphological and other investigations.

An increase in the resources of the mortmass in soil promoted a decrease in the threshold of sensitivity of the microbial complex of leached black soil to the action of pesticides. An increase in the level of the biological activity of soil with an increase in the resources of the mortmass was not accompanied by the intensification of 2,4-D decomposition.

Results of the distribution of microorganisms in peal fields of the landscape profile of the north-eastern part of the Vasyuganskoye Bog are presented.

Organic and inorganic carbon stable isotopes in Transbaikalian sor solonchaks are studied. The ratios of organic carbon stable isotopes in solonchaks varies from

The background ecological status of the geological environment, as well as the complicating n

Specific diversity of urban arboriflora, the status, resistance and the use of native and exotic species in urbanized environment were studied in Novosibirsk and other cities and towns of Siberia as examples.

The lichen species composition was revealed and checklist was constructed, including 371 species from 1 class, 13 orders, 46 families and 93 genera for the territory between two rivers, the Ob and the Chulym. The species which are new for Russia, Siberia and Asia were defined: two species, Verrucaria keisslerii Szat., V. murorum (Arnold) Lindau, were noted for the first time in Russia and Asia. Six species, Endocarpon psorodeum (Nyl.) Th. Fr.,  Lecan

The data on the lichen flora of the Algama basin in the south-east Yakutia are presented. The lichen flora of the studied area includes 102 species of lichens from 40 genera and 15 families belonging to 4 orders. The lichen flora is characterized as a boreal one with the presence of some mountain species. Here, 3 lichens species new for Yakutia have been found; they are: Parmelia squarrosa Hale, Platismatia glauca (L.) W.Culb.et C.Culb., Lobaria pulmonaria (L.) Hoffm.

Demutation of the stands of Siberian linden degraded after an eruption of pathogenic fungi is possible in the case of the natural formation of vegetative young growth. Account of the young growth of linden in the plantations weakened by epitophytotia revealed the necessity of rejuvenation felling.

The dynamics of the phenolic compounds content in Alchemilla vulgaris L. plants introduced from the high-mountain areas of the Altai Mountains to the forest-steppe zone of West Siberia is presented. The content of phenolic compounds in the roots of Alchemilla vulgaris L. is 1,5

We studied vegetation communities, their floristic composition, stratigraphy of peatlands of mesotrophic sphagnum bogs of the basin of the Luza river (a tributary of the Northern Dwina). Rare species of vascular plants and mosses registered in the Red data Book of the Komi Republic, that are growing on these bogs, are of interest for scientists. The data on the chemical composition of surface bog waters is given. Possible economic use of the bogs is assessed.

This paper is concerned with the problem of determining the character of disturbance of plant communities by considering an example of the Lake Baikal

A comparison of the coenofloras of moss tundras, dryas tundras and cryophytic grassy bogs of the Subarctic region of Yamal, Taymyr and Yakutia is carried out. The values to be compared include the parameters of activity and species richness of the ecological groups of coenofloras. The comparison of the three coenofloras of the Subarctic tundras on the basis of the conditions of heat and humidity resources showed that the habitats of Yamal noticeably differ from the habitats of Taymyr and Yakutia. In Yamal, the conditions are warmer in all the habitats except for the habitats of grassy bogs of the zone of typical tundras. The majority of the habitats in Yamal have less humid conditions. The hydrothermic conditions of Taymyr and Yakutia are similar. The given differences are caused by an increase in continentality of climate from west to east.

Consequences of the action of sown perennial grasses on salinization and alkalinization of strongly saline black meadow soil are considered. Perennial grasses provide the conditions for the accumulation of biogenic calcium in the root layers of soil, thus resisting their alkalinization. The obtained data allow one to evaluate the ecological safety of phyto-melioration as a method of saline land improvement.

Soil fungi from the Trichoderma genus were successfully used to protect plants from phytopathogens. Siberian Trichoderma strains exhibiting the high antagonist activity against the phytopatogens of conifers and cereals were chosen for solid-phase fermentation on various plant substrates. The objects of our study were two isolates

For the first time, accumulation and degradation of water-soluble polysaccharides

The flavonoid complexes of the overground parts of four species of  Euphorbia L. from two sections of Esula Pers. subgenus: section  Tulocarpa (Raf). Prokh.

The activitity of flavonol-oxidizing enzymes (flavonoloxidase, peroxidase) in roots and root nodules of cultivars Torsdag, Ramonsky 77 and its supernodulating mutant K301 were studied. The obtained results, demonstrating the connection of phenolic

The information about the structure of flora of the valley of river Tuba is presented. The results of systematical, geographical, zonal, ecological, biomorphological analyses are presented; 21 endemic species, 32 relic ones, 44 rare and disappearing species have been registered in the vegetable cover of the Krasnoyarsk Territory.

The biological-morphological features and ontogenesis of Ferula foetidissima Regel et Schmalh. are considered. The species is widespread in the South-Western Tadjikistan; it is an edificator of big-grass semisavann

The state of male gametophyte of two morphological forms of Taraxacum officin

As a result of investigation of the activity of antioxidant enzymes: peroxidase, catalase and glutathione-S-transferase, their localization and possible size-age dependence in Baikal amphi

As a result of search of the species and strains of entomopathogenic fungi and bacteria virulent to migratory locust (Locusta migratoria migratoria L.), the combinations causing high mortality of insect in a short time interval were found. After the L. migratoria was infected with Beauveria bassiana (Bals.) Vuill and Metarhizium anisopliae (Metsch.) Sorokin, we observed 4

The indices of biodiversity and structure of the complexes of Carabidae of spruce-fir and aspen-birch forest in the gradient of chemical pollution with the emissions from the Sredneural

Retrospective review and modern state of dyn

Distribution of the fish rotan Perccottus glenii Dybowski, 1877 in the North-West Eurasia is characterized by the development of several centres of distribution. Since 1990, populations of rotan are known in the ponds in the vicinity of Tomsk town, which is located considerably far from the nearest sub-ranges of this alien fish (Transural region and the basin of Lake Baikal). In 2005 we performed a special inspection of floodplain waterbodies (N = 81) in Tomsk and Tumen

Biotope confinement and abundance of reptiles were determined on the basis of the data collected during 12 years in the forest, forest-steppe and steppe zones of the Ob region (West Siberia), a connection between non-uniformity of reptile communities with the main structure-forming environmental factors was estimated, and a map of the communities of this animal class was composed.

The main elements of the theory of organization of the communities of many species are considered in the work.

Features of bird distribution over the forest-field ecotones of southern taiga and northern forest-steppe of the Urals are considered. An increase in species diversity and in the number of birds in the field belts near the forest borders is demonstrated, along with avoidance of forest vicinity by the species living in an open space. Ecological and behavioral aspects of these phenomena are considered. A quantitative estimation of the manifestation of the forest border effect and its role in the formation of the spatial structure of bird population of an agricultural landscape is presented.