The species composition and distribution of diatoms in sphagnum bogs of European Russia: Ecosystems of the Volga Upland

The species composition of diatoms in ten sphagnum bogs of the Volga Upland (Penzenskaya oblast) was studied. A systematic and ecologo-geographical analysis of flora was performed. A great number of algae were found (291 species and intraspecific taxon) that differ in specific ecological features and frequency of occurrence in samples. The horizontal heterogeneity of diatom communities in the sphagnum cover was established, and a decrease in the number of species from the center to the bog periphery was determined.     

Characteristics and Main Trends of Anthropogenic Florogenesis in the Southern Volga Uplands

The entire range of aspects of anthropogenic florogenesis in the southern part of the Volga Uplands is addressed. Trends in the anthropogenic dynamics of local flora in the last 100 years have been identified. A shift 50–100 km northward of the southern border of natural habitats of some boreal species (Antennaria dioica (L.) Gaertn., Maianthemum bifolium (L.) F.W. Schmidt, Pyrola rotundifolia L., etc.) has been noted. Data on the adventive flora and modern migration paths of the plants within the study area are provided. The adaptive activity of aboriginal species in relation to the entire range of anthropogenic habitats of the region is characterized. Information on findings of protected plant species in anthropogenic biotopes is provided. Overall, flora aridization and xerophytization have been noted, as has an increased role of tree and shrub life forms in the anthropogenic florogenesis. It is proposed to use a method based on the identification of anthropochorophilic elements in the aboriginal flora to forecast the adaptation of flora to the conditions of anthropogenic habitats.     

Lowland river reference condition: spatial and temporal patterns of the zoobenthos community in the Volga headwaters (2006–2010)

The Volga, the largest river in Europe, has experienced multiple stressors from human activities. Recently we showed that its upper course (about 500 km, from its source to Tver) still has large sections with low impact and a natural type-specific potamal flora and fauna. Our present research in the East European lowlands aim to define reference conditions for mid-sized to large lowland rivers in order to build a basis for future management and conservation. Three monitoring sites were selected based on the results from intensive sampling in 2005. In subsequent field campaigns between 2006 and 2010 regular surveys were carried out each year in summer and additional ones in spring. A taxon-rich macroinvertebrate fauna, including several rare potamal relict species, was recorded and the data was used to provide an overview of annual and interannual variation in community indices and metrics. The conditions described for the headwaters of the Volga River system can be used as a reference state for medium-sized and large lowland rivers in regions where reference sites of these types are lacking.     

Phytogeography of upwelling areas in the Arabian Sea

Aim The identification of the marine plant communities of two islands from different upwelling areas of the Arabian Sea, with a similar diversity in biotopes. A comparison of the species composition of these macroalgal communities and their biogeographical affinities within the Indian Ocean should give insight into the biogeographical position of the Arabian Sea within the larger Indian Ocean. The incorporation of environmental parameters in the analysis is instructive in understanding their importance in shaping the diverse marine assemblages of the Arabian Sea. Location Arabian Sea: (1) the Socotra Archipelago (Yemen; 12.47° N, 53.87° E) in the Somali upwelling area, (2) Masirah Island (Oman; 20.42° N, 58.79° E) in the upwelling area of the southern Arabian Peninsula. Methods The marine flora of different biotopes around both islands were examined by means of qualitative assessments. Ordination analysis [detrended correspondence analysis (DCA)] was used to identify the different plant communities and to correlate these with environmental parameters. The species composition of the identified communities were compared (tripartite similarity index) and their biogeographical affinity with nations bordering the Indian Ocean was determined. Indicator species analyses were performed to identify the characteristic species of the different plant communities and their biotopes. Results The DCA analysis shows a clustering of sites (plant communities) corresponding with their geographical position, linked in turn to the prevailing environmental conditions of the different coastal areas. The combined interpretation of the ordination, similarity and biogeographical analyses results in the aggregation of similar plant communities of both upwelling areas into four biotopes. Main conclusions The north coast communities of Socotra and the west coast communities of Masirah can be grouped into three biotopes related to the degree of exposure (to upwelling) and sedimentation. These biotopes are typified by indicator species, characteristic for specific substrata, and have a high biogeographical affinity with the East African coast. The plant communities of Socotra's south coast and Masirah's east coast constitute a fourth biotope, being diverse and species rich, typified by a large proportion of red macroalgae including the characteristic species of the unique Arabian Sea flora. This biotope has a pronounced biogeographical affinity with distant regions (disjunctly distributed taxa) as South Africa's East Coast and Western Australia. Within the different biotopes, the communities of Masirah are more divergent from an East African flora in comparison to Socotra, the latter being a stepping stone between the East African and Arabian Sea flora.     

Golden algae (Chrysophyta) in plankton of the Volga River reservoirs: Taxonomic structure,dynamics of diversity,and abundance

Long-term (1953–2004) published and original data on the taxonomic composition and ecological and geographical characteristics of planktonic crysophytes have been systematized and the degree of similarity of the crysophyte flora in nine reservoirs of the Volga River basin has been assessed. Patterns of changes in the specific species richness and biomass of golden algae along the longitudinal profile of the Volga River reservoirs are identified. The relationship between species richness and some abiotic and biolimnological parameters has been analyzed. The decline in diversity and biomass of golden algae in direction from the Upper to the Lower Volga in accordance with the geographical zoning is revealed. The long-term dynamics (1954–2011) of the species richness, abundance, and biomass of golden algae has been analyzed. A positive correlation between the diversity and biomass of golden algae and the amount of precipitation and water temperature is demonstrated.     

Anomalies of broad-leaved cattail (<Emphasis Type="Italic">Typha</Emphasis> L., Typhaceae) in a small anthropogenic pond of the Upper Volga basin

An increased anthropogenic impact on the hydrophilic ecosystems of technogenic ponds of the Volga–Caspian basin has enhanced the migration of Typha latifolia L. and closely related species. Due to backcrossings and anomalies among bractless sections of the genus Typha, new morphological traits have been formed in T. latifolia via the stage of a nonspecific form development. Morphological anomalies revealed in an association of Typhetum latifoliae Soó 1927 of a small anthropogenic pond in the Yaroslavl region have been studied.     

Structure of a community of testate amoebae in a sphagnum dominated bog in upper sura flow (Middle Volga Territory)

Fifty nine species of testate amoebae were found in a sphagnum moss bog located in the upper Sura flow (Volga highland). The active diversity in communities of sphagnum moss biotopes was formed by 24 species. Minimal species diversity (3 species) and maximum density of organisms were noted in the driest habitat. In the habitats with the medium humidity levels, the level of species richness was similar (13–16 species) and the total density was determined by redox characteristics of the environment: under the conditions of oxygen deficit, it was two to three times lower than in an oxidized environment. The species composition specificity in sphagnum moss biotopes was determined by the degree of humidity: in the driest habitats, Arcella arenaria predominated; in the biotopes with medium humidity, Nebela tenella and Hyalosphenia elegans; and in the most humid biotopes, Hyalosphenia papilio and Heleopera sphagni. Communities of testate amoebae differed by species composition and integral characteristics at different sphagnum moss horizons: the abundance and species richness increased with depth. The proportion of living individuals in the total number of tests was 35 to 75%.     

Factors influencing the natural reproduction decline in the beluga (Huso huso,Linnaeus, 1758), Russian sturgeon (Acipenser gueldenstaedtii,Brandt & Ratzeburg, 1833), and stellate sturgeon (A. stellatus,Pallas, 1771) of the Volga–Caspian basin: A review

The review describes the changes in natural reproduction of three important sturgeon species in the Volga–Caspian basin: (a) the beluga (Huso huso Linneaus, 1758), (b) the Russian sturgeon (Acipenser gueldenstaedtii Brandt &Ratzeburg, 1833), and (c) the stellate sturgeon (Acipenser stellatus Pallas, 1771). Since the past 60 years, these species responded to severe influences of natural and anthropogenic factors. On the basis of original and published data, an analysis has been made of (a) the numbers of larvae migrating from spawning sites (according to plankton net survey), (b) fecundity and histological anomalies in gonad development, (c) the numbers of adult sturgeons in the Caspian Sea and of spawners migrating to the Volga River (according to trawl and beach seine survey), and (d) foraging resources for the sturgeons. The results show that their natural reproduction in the Volga–Caspian basin has declined drastically during the past decades under the impact of (a) fluctuations of the Caspian Sea level and flow discharge from the Volga River, (b) blockage of sturgeon migration routes and loss of spawning sites because of dam construction, (c) water pollution in the lower reaches of the Volga River and in the Caspian Sea, and (d) intensive and selective illegal and unreported fishing. The relative significance of these factors has been changing during the study period.     

Testate amoebae community structure in the moss biotopes of streams

The specific composition and community structure of testate amoebae in the moss biotopes of streams were studied in the Sura River basin (Middle Volga region). Twenty-nine species and forms were identified. The eurybiont species Trinema enchelys, Euglypha ciliata glabra, Centropyxis aerophila, Tracheleuglypha dentata, Crythion dubium, Centropyxis cassis, Trinema complanatum, and Trinema lineare are dominant. The species richness varies from 2 to 11 species per sample, the abundance is 100 to 4000 ind./g of absolutely dry moss. The degree of forest covering in the basin, hydrochemical peculiarities (the amount of biogenic elements and water hardness) of streams, the size of streams, and environmental contamination are possible factors that determine the specific character of the composition and structure of testate amoebae communities.     

Distribution and special traits of naturalization of new and rare zooplankton species in waterbodies of the Upper Volga basin

More than ten new zooplankton species were registered in reservoirs of the Upper Volga during 2002–2005. Since 2003, the cladoceran Diaphanosoma orghidani Negrea, had intensively settled in different biotopes of Ivankovo, Uglich, Rybinsk, and Sheksna reservoirs and is the most abundant (16 000 ind./m³) in the latter one. The rotifer Asplanchna henrietta Langh. was found for the first time in Rybinsk Reservoir in 1985, and by 2004, this species had also occurred in Ivankovo, Uglich reservoirs, Lake Nero, and some small waterbodies of the basin. In Lake Nero its density reaches especially high values (>1 million ind./m³). Causes, mechanisms, and ecological consequences of the expansion of new zooplankton species are discussed.     

Distribution,population structure,and some biological distinctions of pikeperch <Emphasis Type="Italic">Sander lucioperca</Emphasis> of the channel part of the Akhtuba River (Volga-Akhtuba water system)

Biological traits (distribution, reproduction, age composition, body length and weight) of pikeperch Sander lucioperca from channel parts of the Akhtuba River, remote from the Volga Delta, are investigated. In the investigated stretch of the river, movements of most specimens of pikeperch are local and occur in the deep part (4?10 m) of the channel. Aggregations of fish are not confined to any definite points but move along the extensive stretch of broads. Pikeperch prefer near-bottom biotopes confined to the zone of stable hydrodynamic eddies in places of complicated bottom relief—transverse crests and longitudinal channel crests. For the first time, it is found that pikeperch in the under-ice period move to the shallow zone of submersed inshore shrubs. The age structure and body length and weight of pikeperch differ from those in the Volga Delta and correspond more to the populations from northern and northwestern parts of the species area. Pikeperch spawn only in temporary water bodies of the accessory system, within a short period at the temperature 11?17°С. The data on biology of pikeperch from the Akhtuba channel indicate the populational level of differences from the Volga Delta pikeperch.     

Range expansion of quagga mussels Dreissena rostriformis bugensis in the Volga River and Caspian Sea basin

In 1992, we discovered populations of the nonindigenous quagga mussel Dreissena rostriformis bugensis in the middle reaches of the Volga River. The same species was found in samples collected between 1994 and 1997 in the Volga delta and in shallow areas of the Northern Caspian Sea. D. r. bugensis always co-occurred with its more widespread congener, the zebra mussel D. polymorpha (Pallas 1771). The quagga mussel's contribution to total Dreissena abundance increased over time in the middle Volga reservoirs and Volga River delta. D. r. bugensis was common in the Volga portion of Rybinsk Reservoir during 1997 and, by 2000, it was in Uglich, Rybinsk and Gorky Reservoirs on the Upper Volga River. D. r. bugensis was neither found in Ivankov Reservoir, nor in terminal sections of the Volga-Baltic corridor including the eastern Gulf of Finland. Presently, all but the northern-most regions of the Volga River have been colonized by D. r. bugensis. We hypothesize that its introduction into the Volga River and Caspian basin occurred no later than the late 1980s via commercial shipping that utilized the Volga-Don waterway to navigate between the source Black-Azov Sea region and recipient areas on the Volga River. Larval drift likely contributed to establishment of populations at downstream sites, while human-mediated vectors may be responsible for introductions to upstream locations on the Volga River. We anticipate continued northward dispersal in conjunction with shipping activities.     

Range expansion of quagga mussels Dreissena rostriformis bugensis in the Volga River and Caspian Sea basin

In 1992, we discovered populations of the nonindigenous quagga mussel Dreissena rostriformis bugensis in the middle reaches of the Volga River. The same species was found in samples collected between 1994 and 1997 in the Volga delta and in shallow areas of the Northern Caspian Sea. D. r. bugensis always co-occurred with its more widespread congener, the zebra mussel D. polymorpha (Pallas 1771). The quagga mussel's contribution to total Dreissena abundance increased over time in the middle Volga reservoirs and Volga River delta. D. r. bugensis was common in the Volga portion of Rybinsk Reservoir during 1997 and, by 2000, it was in Uglich, Rybinsk and Gorky Reservoirs on the Upper Volga River. D. r. bugensis was neither found in Ivankov Reservoir, nor in terminal sections of the Volga-Baltic corridor including the eastern Gulf of Finland. Presently, all but the northern-most regions of the Volga River have been colonized by D. r. bugensis. We hypothesize that its introduction into the Volga River and Caspian basin occurred no later than the late 1980s via commercial shipping that utilized the Volga-Don waterway to navigate between the source Black-Azov Sea region and recipient areas on the Volga River. Larval drift likely contributed to establishment of populations at downstream sites, while human-mediated vectors may be responsible for introductions to upstream locations on the Volga River. We anticipate continued northward dispersal in conjunction with shipping activities.     

Zoogeographic analysis of the fauna of the family Asilidae (Diptera) of the Lower Volga area

Based on the author’s own and the literature data, the zoogeographic analysis of robber flies (Asilidae) of the Lower Volga area was carried out for the first time. A total of 21 range types were distinguished and the fractions of different chorological groups in the fauna were determined. The zoogeographic structure of faunal complexes of robber flies inhabiting biotopes with different plant associations was studied.     

Demographic variations in the movements of Upland geese Chloëphaga picta and Ruddy-headed geese Chloëphaga rubidiceps in the Falkland Islands

Recoveries and sight-records were made from 2700 Upland and 470 Ruddy-headed geese marked in the Falkland Islands between 1977 and 1980 in order to describe the movements of these island populations. First-year male Upland geese tended to be sighted further from natal areas than first-year females, once independent of their parents. Second-year Upland geese were sighted further from shedding sites than adults throughout the year. This age-related difference was also found for Ruddy-headed geese in spring. Breeding adults of both species were rarely sighted more than 5 km from their territories. Upland adults moved furthest from their breeding territory during Sate summer and autumn. Significantly more long-distance (over 20 km) movements were recorded for Ruddy-headed geese compared with Upland geese, and were mostly carried out by geese in their second or third year, for both species. The mobility of the geese makes attempts to reduce the population on certain pastures by culling ineffective.     

蝴蝶在生境和生物小区之间的移位伴随着对外来蜜源的利用

在发育成熟的温带环境中,植食性昆虫群落能迅速适应引入植物并将其作为幼虫的食物和花蜜.我们研究了经过森林砍伐的热带环境中蝴蝶对利用引入植物作为蜜源植物的适应快慢程度,并研究了蝴蝶-显花植物在新的生物小区中出现的范围,发现蝴蝶对引入显花植物的利用和探访多于本地植物,这与引入植物在调查地点、生物小区和植物丰度中的普遍性有关.此外,取食花蜜的蝴蝶和显花植物与正在形成的的生物小区有关,例如路边、农田、集约耕地以及花园.在这些新生物小区中,引入植物很重要,因为它们为蝴蝶提供了蜜源.     

Characteristics of plant communities containing St. John’s wort (<Emphasis Type="Italic">Hypericum perforatum</Emphasis> L.) in the Saratov Region

Analysis of 28 plant communities containing Hypericum perforatum L. in five different biotope types has been performed in 17 districts of the Saratov Region. A total of 325 species from 197 genera of 52 vascular plant species have been recorded, with plants characteristic of forest-edge, steppe, and anthropogenic biotopes prevailing in most communities. It has been shown that H. perforatum at the southeastern boundary of its range behaves as an explerent species. The main factor limiting its growth in biotopes of a certain type is the degree of disturbance in the structure of corresponding communities rather than by their taxonomic composition.     

Morphological and Functional Changes in Small Mammals Exposed to Technogenic Pressure

The effect of technogenic pressure on the weight indices of major endocrine glands responsible for adaptation to adverse environmental conditions was studied in murine rodents. The data obtained in technogenic and natural ecosystems were compared. Using the method of morphophysiological indicators, it was shown that exposure to heavy pollution (emissions from lead and zinc smelters) caused a significant increase in the adrenal index of virgin animals (0.45–0.56 mg/g, compared to 0.15–0.33 mg/g in the norm); conversely, the liver index decreased to 39.0–49.0 mg/g (below the lower limit of the norm). The simultaneous increase in the adrenal index and decrease in the liver index of rodents in autumn are indicative of exhaustion, which leads to an energy breakdown and mass mortality. The core of the population in the next spring consists of juveniles coming from the neighboring biotopes with more favorable conditions. Thus, under the effect of technogenic pressure, a temporary population of small mammals is formed every year.     

The taxonomic diversity of the parasites of fishes in the Volga basin. III. Aspidogastrea and Trematoda

A checklist of Aspidogastrea and Trematoda parasitizing fishes in the Volga basin is given. The checklist includes host species names for the each parasite and data on the occurrence of parasites in different parts of the Volga basin. The data on trematodes from 69 fish species are presented. The list containes 107 species and 1 subspecies names of trematodes, and 1 species of Aspidogastrea. The family Diplostomidae is represented by the most number of species (22). Six species of trematodes (Amurotrema dombrovskajae, Sanguinicola skrjabini, Nicolla skrjabini, Plagioporus skrjabini, Apophallus muehlingi, Rossikotrema donicum) have been introduced into Volga River along with aclimatizated fishes or penetrated into its basin by self-migration to new water bodies.     

Invasion genetics of a freshwater mussel (Dreissena rostriformis bugensis) in eastern Europe: high gene flow and multiple introductions

In recent years, the quagga mussel, Dreissena rostriformis bugensis, native to the Dnieper and Bug Limans of the northern Black Sea, has been dispersed by human activities across the basin, throughout much of the Volga River system, and to the Laurentian Great Lakes. We used six published microsatellite markers to survey populations throughout its native and introduced range to identify relationships among potential source populations and introduced ones. Mussels from 12 sites in Eurasia, including the central Caspian Sea and one in North America (Lake Erie), were sampled. Field surveys in the Volga River basin suggested that the species first colonized the middle reach of the river near Kubyshev Reservoir, and thereafter spread both upstream and downstream. Evidence of considerable gene flow among populations was observed and genetic diversity was consistent with a larger, metapopulation that has not experienced bottlenecks or founder effects. We propose that high gene flow, possibly due to multiple invasions, has facilitated establishment of quagga mussel populations in the Volga River system. The Caspian Sea population (D. rostriformis rostriformis (=distincta)) was genetically more distinct than other populations, a finding that may be related to habitat differences. The geographical pattern of genetic divergence is not characteristic of isolation-by-distance but, rather, of long-distance dispersal, most likely mediated by commercial ships' ballast water transfer.