Home – Home – Jornals – Contemporary Problems of Ecology 2017 number 2

Estimations of CO₂ emission and net ecosystem exchange (NEE) between atmosphere and bog surface were made in south taiga of European Russia for summer seasons of 2013-2015. Flux measurements were carried out by static chamber method every 7-10 days on 3 homogeneous in soil moisture and vegetation type experimental sites. Statistically significant distinctions of NEE and CO₂ fluxes were found between different experimental sites. It has been established that bog significance in CO₂ balance to atmosphere should be assessed with regard to the spatial heterogeneity of bogs.

The results of long-term evaluation of carbon stock and current carbon sequestration based on the example of pine-dwarf shrub-sphagnum biogeocoenoses on Vasyugan mire are given. In different climatic conditions (different years) NРP varies from 206 to 337 g C m^-2 x year^-1. An increase in intensity of carbon emissions was revealed in drier vegetation periods. Most of the carbon losses are determined by emission of carbon dioxide (the average is 61.3 g C m^-2 x year^-1, or 23.5 % of NPP). Progression of peat formation may be stated. The removal of the carbon by mire waters calculated by the mathematical model is 3.0 % of NРР with an average value of the removal of 7.9 g C m^-2 x years^-1. On the basis of the model of vertical growth of mires was calculated present-day rate of carbon accumulation from 10.3 g C m^-2 x years^-1 in polygonal mires to 51.7 g C m^-2 x years^-1 in grassy mires.

Based on the example of Krivoye Lake (North Karelia) dependence of productivity of lake ecosystems on geographical, climatic conditions, and drainage terrestrial production is described in the form of dynamic mass-balance model. A model algorithm is presented. It has been concluded that at natural interannual fluctuations of nutrient loads and owing to absence of anthropogenic influence Krivoye Lake has been keeping the status of oligotrophic waterbody over more than 40 years.

The results of study of the ratio of hydrothermal (temperature and precipitation) conditions and ecological spectrum of the flora of vascular plants of the Tom river basin are presented. On the basis of the calculated coefficients of linear correlation between average monthly temperature data and sediments and environmental groups of model basins, it was found that the influence of the main parameters of hydrothermal regime (temperature and precipitation) on the plains and in the mountains, in varying degrees, affected the ecological spectrum of the flora. Hydrothermal conditions of the cold period of the annual cycle have the greatest impact on environmental features.

Historical changes in distribution of animals in European Russia are of permanent interest to specialists. To this end information contained in the Economic Notes to the General Land Survey of the Russian Empire (XVIII-XIX centuries) is of particular importance. The article presents the first results of the data analysis of mammalian fauna in the boreal forests of European Russia. The data are contained in a systematic sampling arranged on the basis of the Economic Notes and cover 7 provinces, 32 counties, and 377 specific dachas. There are 1774 animals mentioned (21 names of animals (species), 10 families and 5 orders). A comparison of distribution of certain species the most characteristic and significant for boreal forests in XVIII-XIX centuries and at the present time has been made.

The site of open shallows of the Volga Reach in the Rybinsk Reservoir (Volga) subjected to impact of common heron colonies was studied in 2009-2011. Some changes in phytoplankton community composition typical of water trophic level rise were noticed. Floristic wealth reduction along with increase in biomass due to phytophlagellates - cryptophytes, euglenales, dinophytes and chrysophytes, as well as flagellar forms of green algae were registered at the heronries. Changes in phytoplankton communities were temporary and connected with herons nesting period, which allows to treat the studied site as “traumatic” ecotone.

Traphic relationships were examined for macroinvertebrates and fish inhabiting St. Petersburg methane seep (Central part of lake Baikal, ~1400 m depth). The analyses of the values of carbon and nitrogen stable isotopes showed that all animals associated with the seep were heterotrophs with different feeding strategies, symbiotrophs were absent. Seep enimals consumed combined food with different portion of methane derived carbon ranged from 2.7 to 89 %. The average values of the δ¹³С varied from -26.2 ‰ (in benthopelagic amphipods) to -64.5 ‰ (in gastropods). The trophic food web of the methane seep consisted of filter feeders (pelagic amphipods TP 1.9), detritophages (gastropods TP 2.2 and burrowing amphipods TP 2.1), polyphages (nectobenthic and bentho-pelagic amphipods TP 2.8-3.2), and predators (flat worms TP 3.6-4.2 and cottoid fish TP 3.0-3.8). Animals occupying the similar trophic positions differed significantly in the δ¹³С values and utilized partly overlapping different food components.

The aim of the current study was to assess synergistic effect of thermal stress, pollution and parasitic infestation on the activity of antioxidant enzymes (peroxidase, catalase, and glutathione-S-transferase) in different populations of the wide-spread species of pulmonate mollusk Lymnаea stagnаlis distributed in the Belarus Republic water bodies. It has been shown that the combined influence of anthropogenic effect and parasitic infestation on the one hand and experimental hyperthermia coupled with the parasitic invasion on the other hand affect the activity of peroxidase. The combined impact of parasitic infestation and contamination of the reservoir leads to the change of the catalase activity. No significant correlations between the studied factors and the activity of glutathione-S-transferase were found. The simultaneous exposure to elevated temperature, pollution and infectiousness of mollusks does not affect the activity of the studied enzymes.

The research was conducted in the southern part of the forest-steppe zone of West Siberia (Novosibirsk oblast’). The spatial-temporal structure of the spider community was studied at the continuous chain of habitats (180 m long) from the central part of small birch-aspen forest to the center of meadow site. We applied two sampling methods which completed each other: pitfall trapping and hand separating soil samples. Over 5000 specimens of spiders from 83 species and 14 families were collected during 2007-2008. Spiders are most abundant in June and less abundant in July. Representatives of different families are maximally abundant in different sites: Lycosidae and Gnaphosidae mainly in the forest, and Philodromidae - in the solonetz meadow. The distribution of diversity and abundance of spiders and carabids through the habitat gradient is generally similar. This is controversial compared to the spatial interactions of these two groups of predatory arthropods in extreme ecosystems: in Arctic and near saline lakes. Niche distinguishing between carabid and spider species is not only topical. It includes use of different strata of vegetation, various seasonal activity and trophic specialization.

The following biomarkers of oxidative stress: catalase (CAT), glutathione-S-transferase (GST), glutathione and reductase (GR) activities as well as malondialdehyde and reduced glutathione content and heavy metal concentrations (HM) were studied in Dreissenа polymorpha tissues. Mussels were collected on three sites located in the Rybinsk reservoir differing in the levels of anthropogenic load: more polluted sites 1 and 2 and relatively clean site 3. Mussels from sites 1 and 2 had higher concentrations of HM and their response to pollutants’ action was manifested in increased processes of LPO, activation of CAT and elevated level of GHS.

The distribution of bioorganic components and compounds of anthropogenic and mixed origin in the sediments of freshwater lake Black and salt one Tus (Khakasiya) was studied by the method of gas chromatography-mass spectrometry. The contribution of major sources of organic matter to the bottom sediments was evaluated. It was found that the formation of the composition of the bottom sediments was mainly due to compounds of biogenic and mixed origin. The sites with high concentration of contaminants: pyrogenic and oil hydrocarbons and izoalkilbenzols - possible products of surfactants degradation were revealed.