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We quantified the soluble fractions of the soil organic carbon (SOC) concentrations and the total and water-soluble trace elements in soils contaminated by household waste and remediated via the addition of green manure over 13 years and identified the main factors controlling the vertical distribution and accumulation of the trace elements. Green manure favoured the active formation of soil organic matter. The SOC of the examined soils was characterised by the active stabilisation by mineral soil compounds, but by a low degree of humification. The soils showed increased concentrations of Cr and Ni ions. The SOC and different soil compounds enriched by Si, Ca, and Mn ions were the important determinant for the distribution of Sr, V and Cu ions, as well as for the distribution of Pb and Cr ions bound to the water-soluble components of the soils. The low degree of SOC humification may be one of the main reasons of the high concentrations of Cu and Pb ions in the composition of the water-soluble soil compounds. The nickel ions were mainly associated with compounds enriched by the Al and Fe ions. The extremely high percentage concentration of the Ni ions in the water-soluble components of the soils may be result of the absence of the Ni ions adsorption by humic substances.

Features of the marking activity of beavers in the channel-type settlements are considered. On the basis of statistical data it was determined that the signal hillocks may be recommended for investigation of dynamic indexes of scent marking by beavers. On the basis of quantitative methods the role of the level mode of water streams in the appearance of olfactory marks is demonstrated; as a result, the inversely proportional dependence between these parameters has been revealed.The evermore increasing area occupied by technogenic systems makes the problem of natural population control more and more acute. Regulation of the number and spatial distribution of key ecosystems and animals of exploited population group remains the most topical. Measures on direct extermination provide short-term effect which ecological value remains underestimated [1][2][3]. The best results are achieved by the methods of biological control influencing the animals'receptor systems with the view of obtaining certain behavioral response [4][5][6]. However, wide application of such methods requires additional investigation of animals' orientation means, their methods of exhibiting territoriality and signaling. It is well-known that for the majority of mammals the leading role in communication between species and their aggregates belongs to chemical signals [7,8]. Castor fiber (Linnaeus, 1758) is a convenient object for investigation of the issues of olfactory communication. Unlike other model species which behavior was studied (sable, mink, musk-deer, field-vole, etc.) it does not mark the territory with fecal matter [7]. The product of beavers' preputial organs and secretion of anal glands are characterized by easily identified smells and are laid (in the majority of cases) on specific substrate [9].Despite a significant number of works related to scent marking of the species there are many ambiguous statements, contradictory data and unexplored aspects [10,11]. Besides there are data indicating limited extrapolations of investigation results in the beavers' family (Castoridae) due to reliable differences in changeability of scent marking, in chemical composition of specific glands' secretion and lability of adaptation mechanisms of different species [12][13][14]. In territorial behavior of the animal uniformity of settlement use and timing of different marks to its spatial and functional parts and infrastructural elements remain unclear; the role of tropical factors in appearance and renewal of olfactory marks has not been clarified. Despite numerous data on the diverse methods of olfactory signaling (on the ground, hillocks, parts of trails and prominent subjects) in all known works [9, 15-17, etc.] except for [18] marking behavior of beavers was described only on signaling hillocks.The objective of this research is to study the features of marking activity of beavers in channel-type settlements. To reach the objective it is necessary:-to study regularities of dynamics of different types of olfactory marks; -to determine the most regul...

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In order to study the spatial distribution of biological and ecological patterns on the territory of the Volga region, geobotanical indication of flooding and salinization of the lands these regions was carried out. Geobotanical indication is used in the study, assessment, mapping and monitoring of territorial complexes and their components and is based on the analysis of the relationships of the geographical envelope as a whole. The article is the result of many years of interdisciplinary research. It is based both on the data obtained by the authors as a result of agro-landscape and ecological zoning and in the course of field expedition research, and on the analysis of long-term series of statistical information and literature sources. Intensive economic activity that requires the use of large amounts water resources, against the background of modern climate changes, leads to waterlogging in large areas. The weakening or termination of economic activity, the decrease in the volume of water resources used under certain conditions leads to the spread of land salinization. Flooding and salinization of arid lands near reservoirs, channels, reclamation facilities, functioning and abandoned irrigation fields, etc. occupy significant areas and are of great importance as environmental problems in the Volga region. The most dynamic and fast-responding biotic component of ecosystems to the occurrence of flooding and salinization is vegetation.