Vol 9, No 3 (2016)

This paper generalizes the data obtained in 1995–2014 in the regions of the Sulak and Turali lagoons of Dagestan (the western coast of the Middle Caspian). The lagoons are located in a “bottleneck” that is a narrow migration corridor traversed by one of the largest migration routes of trans-palearctic species in Russia. This route is a part of the West Siberian–East African migration range. The migration traffic and territorial localization of the Laridae populations participating in the total migratory flow along the western coast of the Caspian Sea have been determined. The present-day migratory range of Laridae that covers the space from West Europe to the Baikal Lake and West India is specified. It is determined that Dagestan is crossed not by one but two independent and stable migration flows of Laridae, which fly across the transit region in different migration routes, but at the same periods of time. Three types of migration intensity of Laridae across the study area are defined: weak, average, and mass migration. Both spring and autumn migrations include five peaks of migration activity (migratory waves). Migratory timing, taxonomical composition, and abundance of different Laridae species vary for each degree type of migratory waves. The key determinants of migratory wave intensities are the abundance of migratory populations and weather conditions of a year. Over the last 5–7 years there has been a steady decrease in the abundance of some Laridae species on the western coast of the Middle Caspian that takes place under the impact of a set of regulating factors, which act across the whole migration range. The decrease in the abundance of migratory Laridae leads to a “blurring” of clear boundaries between migratory waves and migration intensity, changing migration routes of some Laridae populations, which now have shifted from traditional wintering routes along the western coast of the Caspian Sea and countries of the Middle East and northeastern Africa to India.

The results of ecological and phylogenetic studies of femtoplankton, the smallest size fraction of plankton formed by viruses and ultramicrobacteria (UMB), are overviewed to shed light on the problem of transbiome invasions by microbes. Phylogenetic lineages of viruses and UMB are shown to be associated with particular biomes, thus indicating infrequent transbiome transitions in the microbial world. An alternative hypothesis of widespread cross-colonization events requires a deeper analysis of the factors that form the barrier between biomes and are responsible for the adaptation of microorganisms to different environments.

The complete cycle of the structure transformation of shrew model taxocene in southern Sakhalin was revealed by investigations of 2008–2014. It was shown that in the communities of these animals facultative and obligate dominants are absent and a dominant group is formed every year of common species. There are two main patterns of the taxocene structure: the monodominant type, predominating by the long-clawed shrew at low number of other species, and the polydominant type, in which one of the background species plays a role of codominant at a lower number of long-clawed shrews. It is found out that the dominance structure in shrew taxocene is not closely related to the phase of its quantitative dynamics.

The abundance, biomass, and production (Р_В) of bacrerioplankton; the taxonomic composition, abundance, biomass of heterotrophic nanoflagellates (HNF) and the rate of consumption of bacteria by HNFs; and the abundance of virioplankton, frequency of visibly infected bacterial cells, virus-induced mortality of bacterioplankton, and viral production were estimated in the mesoeutrophic Rybinsk Reservoir. The rate of bacterial mortality due to viral lysis (7.8–34.1%, on average 17.2 ± 2.0% of daily Р_В) was lower than the consumption of bacteria by the HNF community (15.4–61.3%, on average 32.0 ± 4.2% of daily Р_В). While consuming bacteria, HNFs simultaneously absorbed a significant number of viruses residing on the surface and inside the bacterial cells.

In the present study, the process of biofilm formation in iron-containing aqueous medium in the presence of different organic compounds with different bioavailability (yeast extract, peptone, and humic substances) is considered. Investigations conducted using a scanning electronic microscope and X-ray diffraction analysis allow us to reveal the presence of biologically produced goethite (α-FeOOH) in the crystal structure. It was supposed that the supply of surface waters contaminated with organic compounds to ironcontaining underground waters could increase the risk of plugging aquifer pore space by biogenic iron-containing minerals.

Four types of mountain forest steppes have been specified in the Altai-Sayan mountain region. It has been shown that each type corresponds to a particular bioclimatic sector. The pattern of the mountain forest-steppe belt vegetation has been characterized for each of the types. The peculiarities of mountain forest- steppe vegetation changes with the increase of climate aridity conditions are described within 3 series: the primary Altaian, the primary Khakas-Tuvinian, and the secondary Khakas-Tuvinian series.

This article presents the results of an analysis of ontogenetic and vitality structure of seven cenopopulations of Oxytropis sulphurea (Fisch. ex DC.) Ledeb. in the high-altitude conditions of Rydny Altai (Ivanovsky and Prohodnoi ridges) and the Saur Ridge. In the study of the demographic structure it has been determined that most populations from undisturbed habitats are characterized by left-side spectrums with maximums on juvenile or immature individuals. The changes in the structure of the studied ontogenetic spectrums of this species depend largely on the presence of anthropogenic influence. Grazing pressure has led to the formation of spectrums with a maximum on g₃ plants. The vitality type of the O. sulphurea populations varies from exuberant to depressed; the depressed and balanced types of vitality prevailed. Intensive seed propagation provides a stable existence of O. sulphurea in the high-mountain alpine zone. The results of our study show that O. sulphurea is an alpine-meadow species which has strict ecological and cenotic propensity for alpine meadows with the prevalence of Festuca kryloviana, Anthoxanthum alpinum, and Schulzia crinite and shrub tundras with Dryas oxyodonta.

The process of the Fragaria × ananassa naturalization in Western Siberia lasts approximately 80 years from the moment of the appearance of first garden strawberry cultivars at agricultural experimental stations in 1933. The species invasive status changed slightly for such a long period of time (from casual alien plants to naturalized plants), and it corresponds to colonophytes in regards to degree of naturalization. The ornitochory is one reason the F. × ananassa appears in natural phytocenoses. At present, the F. × ananassa naturalization occurs in two directions, including genetic transformations in long-living coenopopulations and the reinvasion of new ecotypes of the same species in natural phytocenoses. The high death of seedlings in naturalized F. × ananassa does not allow the species to actively occupy regeneration niches in natural phytocenoses, which precludes the invasive plant status for the F. × ananassa at this stage of the F. × ananassa naturalization in Western Siberia.