Home – Home – Jornals – Contemporary Problems of Ecology 2012 number 6

Under the laboratory conditions, we studied water migration and degradation of shaimskoy oil in the soil of bogs of the Khanty-Mansi Autonomous District, as well as the toxicity of successive portions of water extracts, using test objects Ceriodaphnia affinis, Paramecium caudatum, Allium cepa. It is established that oil (up to 2 g/kg) is retained by the humic matrix of peat and does not pass into water. At the same time, the bioassay method allows to fix the toxic effect of the leachate of oil-contaminated peat even in cases when petroleum products are not detected by means of IR photometry.

Oil biosorbents (patents № 2299181, 2318736) were obtained with the help of immobilization into hydrophobic sorbent Sorbonaft manufactured according to the special technology at the Press-Torf company, and oil-oxidizing microorganisms. Two associations of aboriginal hydrocarbon-oxidizing microorganisms were used for this purpose: fungal and bacterial-yeast. The application of biosorbents resulted in substantial acceleration of the process of purification from oil. A decrease in the amount of oil in water and in soil during one month was 30-44 % in versions with preparations against 5 % in the reference.

The algorithm of determining the content of oil products safe for plants and microorganisms in soil subjected to recultivation is presented. The algorithm includes laboratory modeling of recultivation of soil samples containing different amounts of oil products, determination of biological parameters providing an integral characterization of the soil state in these samples, and analysis of the results on the basis of the statistics of chance ratio, which allows one to determine the content of oil products starting from which the state of oil-polluted soil reliably has no differences from the reference.

In the areas of local soil pollution with heavy metals (HM), high-protein low-ash mesopedobionts with the smallest background concentrations of Pb, Zn, Co, Sr (oligochaetes, chilopoda, and some coleopterans) more often fix increased concentrations of these pollutants in their biomass compared to other invertebrates. Such creatures are the most HM sensitive and their mass species can serve as bioindicators. The biological consumption coefficient is not suitable for the ecological control. The bioindicator-control within the same geochemical background seems more appropriate to serve this purpose. It is of decisive importance when norms of maximum technogenic pressure on the soil are set.

Results of the investigation of soil in the mouth part of the territory between the Angara and the Belaya rivers in the zone affected by the chemical plant in Usolye-Sibirskoe are presented. We present an estimation of the degree, scale and character of the areal distribution of mercury concentrations, as well as the concentrations of sulfate and chloride ions. Prevalence of the surface sink of mercury over the soil interflow is revealed. The main fields of anomalous concentrations of mercury and the anions are confined to the industrial zone of the chemical plant. A correlation of mercury with organic carbon and sulphate ion was discovered for the humus horizons of soils; a correlation of mercury with the oxides of iron and aluminium, manganese, titanium, and phosphorus of the mineral horizons of the studied soils was detected.

Total content of heavy metals Zn, Pb, Cu, Cd in soil in Ust-Kamenogorsk (Republic of Kazakhstan) was determined. The mosaic character of heavy metal content depending on emission sources was revealed. The areas of the city having the maximal accumulation of heavy metals were detected.

Communities of oribatids in the soil of urban ecosystems with different levels of pollution with heavy metals and arsenic, recreation load and surface transformation were studied. The suppressing action of these types of anthropogenic press on oribatid communities was revealed. Recreation load manifesting itself as an increase in the density of soil composition and elimination of the sod horizon, as well as the formation of urbanozem, and its effect on oribatids is comparable with the effect of pollution. Among oribatids, we revealed the species indicating the disturbed state of communities and purity of ecosystems.

Features of the development of the steppe chernozems were established, based on the study of soils of different age groups on archaeological sites. Differences in the formation of phytomass and morphological maturity of the soil profile in different age successions recovery were shown. Regional model of the humus horizon steppe soil over time allowed us to estimate the time interval at which the processes of humus accumulation and morphological maturity of the soil profile are relatively equilibrium - 1700-1900 years.

Microbiological composition of the soil of the unique island Tit-Ary in the lower reach of the Lena river was studied fort he first time in detail. The features of the microbial population of cryozem were revealed: high number of individuals in all the groups of microorganisms (10⁴-10⁸ CFU/g), which is comparable with the density of microbes in the steppe soil of Transbaikalia, and the special character of their distribution over the soil profile without a decrease in number with depth. Oligonitrophilic bacteria dominated in the humus-gley soil of the polygon valik tundra; their number varied from 70 thousand to 330 mln CFU/g of soil.

It was found out that the growth and development of Nitraria individual plants and the area of existence of its populations in landscape are determined by the type and level of salinization. It was determined that the range of favourable ecological contents of salts in soils for Nitraria under sulfate conditions is wider (0,7-3,4 %) than under chloride conditions (0,2-0,6 %). Plants are showing some adaptive behavioral reactions, which contribute to maintenance of optimal salts level within the bounds of their locations in response to changes of the level of salinization.

Еffects of different land use intensity (phytomass semi-cutting and all-cutting) on structure characteristics of plant community and soil moisture in a natural vegetation enclosure and an artificially-aided enclosure were investigated in a sandy grassland in Northern China. No-cutting (phytomass kept nomal) was taken as the control treatment (CK). Analyzes showed that: 1) Importance value of the dominant species of different cutting treatments was in the range of 0.47-0.75. The influence of different cutting intensities on species composition was not significant for the same fenced method; 2) Both the diversity indices and the evenness index of shrub layer for the two enclosures were in the order: CK > semi-cutting > all-cutting; the similar indices of the plots of same cutting intensity and different fenced methods were smaller than 0.3; 3) The above-ground biomass of all-cutting treatment was significantly less than that of semi-cutting treatment, and CK had no significant difference from semi-cutting treatment; 4) There were significant differences in soil moisture between all-cutting and semi-cutting. The soil moisture of different layers within 80 cm increased with the increase of cutting intensities. In 0-30 cm, the soil moisture in different cutting intensities was increased with depth; however, in 30-70 cm, it decreased quickly with the increase of soil depth. Soil moisture under different cutting intensities and CK was in the following order: all-cutting > semi-cutting > CK. It proved that land use has some regulation and improvement effects on soil moisture.

The work deals with the aspects of rational ecologically safe irrigation-based agriculture on chernozem, the major automorphous type of soil in the forest-steppe and steppe zones of West Siberia. The actual ability of permanent grasses to recover the initial (before start of irrigation) hydrogeological state of chernozem disturbed by unnormalized irrigation was demonstrated. An economical method of governing the water consumption schedule of soil under the conditions of irrigation is proposed.

Investigation showed that long-term application of chlorine-containing potassium fertilizers at the background of NP promoted an increase in the concentration of water-soluble forms of chlorine and fluorine in soil. The distribution of chlorine over the soil profile was uniform, the concentration of water-soluble fluorine decreased backward along the profile. Systematic application of phosphorus fertilizers caused noticeable accumulation of total fluorine in the topsoil. With balanced nutrition of plants with macroelements and increased crop-producing power, substantial decrease in the content of water-soluble iodine in topsoil was detected. Long-term application of mineral fertilizers did not affect the total iodine content in the soil profile of the agrocenosis.