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Data on the status of summer phytoplankton of the Usa river and its tributaries are given. 184 taxa of algae with a rank lower than the genus from 7 divisions were recorded in algoflora, with Bacillariophyta (43-57% of the composition) and Chlorophyta (23-47%) predominating in the rivers. The abundance range in algocenoses was 0.02 - 5.2 mln cells/L, that of biomass was 0.01 - 1.8 mg/L; the content of chlorophyll-a was 0.01 - 3.1 µg/L.

The effect of gamma radiation doses of 0, 2.5, 5.5 and 7.5 Gy received by Artemia cysts on the hatching of nauplii and post-nauplial survival of crustaceans was studied at salinities of 0, 9, 18, 36, 54, 62, 78 and 88 g/L. Under the same salinities, the above parameters were also estimated without irradiation. It has been found that the rate of nauplii hatching from cysts primarily depends on salinity, the coefficient of determination being 90%.

With the urban-type settlement Stepnoe as an example, biodiagnosis of the soil of a settlement with low technogenic impact was conducted. In the course of our work, 30 soil samples were plated onto solid nutrition media to evaluate the following: the total numbers of heterotrophic microorganisms - on meat peptone agar, the numbers of hydrocarbon-oxidizing and iron-oxidizing microorganisms - on their corresponding selective media, and the activity of several soil redox and hydrolytic enzymes (dehydro-genases, catalases, peroxidases, and invertases) were also studied.

The Common hamster (Cricetus cricetus) is the rodent with one of the largest range (6 million km²). There were four phylogenetic lineages earlier recovered in Western Europe, Ukraine and Bryansk Province of Russia: “North”, “Рannonia”, E1 and E0. E1 was previously reported from South-Eastern Poland and Western Ukraine and never been found in sympatry with “Pannonia” although the closest distance between them was estimated as 20 km. The question is whether the sympatry of E1 and E0 phylogroups exists?

The Haematopus ostralegus longipes population numbers in the conditions of the middle reaches of the Medveditsa river in the nesting period of 1996 – 2008 was stable, namely, 3 pairs, of which two, rarely three ones, nested annually. The egg laying size was 2–3 eggs. In the course of our many-year survey, a tendency has been established to significant reducing the reproduction success level against the background of transformations of the nesting and feeding stations, which is determined by the long-term tendency to reducing the water content in the river.

Morpho-anatomical features of the seeds of seven species from the Iris genus of the Saratov regional flora, which are important in plant adaptation to environmental habitat conditions, are presented. The seeds of two species, namely: I. halophila Pall. and Iris pseudacorus L. seem the most revealing from this viewpoint. The strategy of I.

An approach to allow monitoring contamination of watercourses by registering changes in the space-time parameters of cells and their external structures by ATR-IR spectroscopy with the use of dialysis cultures of Synechococсus sp. PCC 6301 is offered.

The paper presents the results of our research on the foraging activity of ants in forest-steppe biotopes of the Saratov region. The food spectrum of ants was found to include small invertebrates (mainly insects), plant seeds and aphid honeydew. Ants are able to switch to the most massive type of food. F. pratensis behaves as a species with a daytime or morning-evening activity type, depending on the weather conditions. F. rufa is a species with a daily activity type.

According to a forecast of the specialists from “Centrokhotkontrol”, due to the natural climatic cyclicity, a recurrent reduction in the population of ungulates, the moose in particular, should occur in Russia from 2007 - 2010, which “will lead to a recurrent significant age minimum number” in the 2020s (in 2014 - 2015 in Central Russia). In reality, the abundance of the majority of species, including the moose, the European and Siberian roe deer, the red deer, the sika deer and the reindeer, has been steadily growing despite this “trophiclimatic” forecast.