Lichen biota in the low land of the Ob basin

The article reviews the lichen diversity in the low land of the Ob basin based on the data published by the author and other specialists. So far, species diversity has reached 430 taxonomic units from 102 genera and 42 families. There are data about the distribution of certain lichen species for the main types of habitat and substrates with in cenosis. The largest variety is shown in communities of dark coniferous forests and mixed forests with declining aspens in the tree layer (215 species), of forested fens (161 species), and inundated forest cenosis (100 species). The least variety is found in ground slope communities (13 species) and phytocenoses of transition moors (12 species).     

An annotated list and current state of ichthyofauna of the Middle Ob River basin

Abstract

The paper contains a complete annotated list of freshwater ichthyofauna of the Middle Ob River basin. The list is based on an analysis of publications and on the results of the authors’ research, and it includes 43 species in two classes, 9 orders, 12 families, and 30 genera. Ten of all listed species are introduced and only seven are naturalized. For each species, taxonomic comments are provided where necessary and conservation status, distribution within the Middle Ob River basin, abundance and commercial value are indicated. Latin and English names are given.     

Oil contamination of the Ob basin

Oil contamination of bodies of water in the Russian Federation is one of the most widespread impacts on ecosystems. The Khanty-Mansiysk autonomous district-Yugra, the main oil extraction area in Russia, is one of the most oil-contaminated regions. The article summarises data from hydrochemical research on the level of petroleum hydrocarbons in water and bottom sediments of water bodies located in the basin of the river Ob.     

The ecological peculiarities of the testate amoebae population in the Middle Ob flood plain

The biodiversity and distribution of testate amoebae in the Middle Ob flood plain soils have been studied. The biodiversity of Testacea in the soils consists of 83 species and varieties from 12 families. The population of Testacea in flood plain habitats is rich in water forms, especially in the flood plain part of the catena, because of annual floods. The study showed that the density of Testacea in the forest plots is approximately 10 times higher than in the meadow ones. The species diversity of Testacea in the meadows of the flood plain includes 40 species and varieties. It was found that there is an enrichment of the fauna of Testacea in the flood plain meadows with water forms and a decrease in the population of Testacea in the soil according to the depth. The decrease in the diversity and number down the soil profile is related to the decrease in the amount of the oxygen available and general induration of soil. On the whole, the population composition of Testacea in the soils of the pine forest consists of typical representatives of humus substrates with low values of pH, small stock of humus and mineral nutrition. The soils of mature pine forests are rich in Testacea; they have a similar complex of morphological types, mainly because of the moss cover and forest litter thickness.     

Macrozoobenthos diversity of the Middle Ob river tributaries

Abstract

The data show quantitative and qualitative composition of macrozoobenthos of the 12 left-bank confluences of the Middle Ob. The research has documented the presence of various groups, such as Oligohaeta, Diptera, Odonata, Hirudinea, Tabanidae, Trichoptera and Mollusca. The chironomids, molluscs and leeches play a significant role in the generation of biomass in the surveyed streams, and the abundance mostly depends on chironomids, oligochaetes and leeches. In general, zoobenthos abundance ranges from 8.8 (the Shudelka river) to 1839.9 (the Kochebilovka river) ind./m², biomass is from 0.08 (Tatosh river) to 8.37 (Lozunga river) g/m². The amount and benthos biomass of the Middle Ob’s second-order tributaries is higher than in the first-order tributaries.     

Resources,regime and quality of surface waters in the Ob River basin: history,current state and problems of research

The paper presents the history and major results of research into resources, regime and quality of the surface water in the Ob basin, concentrated in such water bodies as glaciers, rivers, lakes, reservoirs and wetlands. Studies have long been carried out by such government agencies as the Hydrometeorological Service (Hydromet), the Ministry of Energy and others, engineering organizations, scientific research institutes of the academy of sciences and universities. The studies included large complex tasks aimed at economic development of the basin territory. By the 1980s, an expanded network of stationary hydrological observations existed, and basic information about the factors of resources formation, regime and surface water quality, as well as long-term dynamics of hydrological characteristics had been obtained. Today, a multidisciplinary and interdisciplinary approach to the hydrological cycle and geo-run-off at the global and regional scales is related to the changes in climate and the environment in general.     

Landscape and environmental characteristics of slope mires in the mountains of the Ob river headwaters

The paper reports the landscape-ecological characteristics of one geomorphological type of Siberian mountain mires – slope mires. The dynamics of vegetation dependent on the mire massif development stage is described.     

Lake Mundshtuchnoye,a unique natural monument of the Middle Ob basin

Lake Mundshtuchnoye is located in the basin of the Middle Ob, upstream from the influx of its big right-bank tributary, the Tym river. The lake is located within the boundaries of the Tomsk region and is a specially protected natural area of regional importance. Genetic and morphological characteristics of the lake allow us to consider it as a natural monument. It is an important point for conducting scientific research and organizing long-term environmental monitoring. The depth of Lake Mundshtuchnoye reaches 55 m, which is a unique phenomenon for the lowland part of the Ob basin. The shape of the lake basin is also unusual, sectionally resembling a crater. Structural-tectonic features of the area of the lake location allow to link its origin and development to the penetration of reservoir fluids. The lake water is very different from the lake waters of the Ob basin water logged catchment areas. Lake Mundshtuchnoye has low salinity (the amount of basic ions is 7.3 mg/dm³), and a significant concentration of silver. The lake water is clear, and thus very different from the dark-coloured water found in most regional lakes because of inflow from bogs and mires.     

Population structure and condition of Siberian sturgeon stock: Acipenser baeri Brandt in the River Basin of the Ob

This paper summarises materials from various sources and the author’s research on the biology of the Siberian sturgeon in the Ob basin. The paper evaluates the significance of various parts of this river system for habitation and formation of sturgeon stock. It has been possible to distinguish semi-diadromous sturgeon and four local (indigenous) schools, according to the difference in morphological characteristics and peculiarities of the Ob basin ecology. Semi-diadromous sturgeon spends most of their life in the lower reach of the Ob and in the Gulf of Ob and migrates to spawn to the upper Ob. These spawning migrations cover a distance of 2500?km or more. Spawners from local schools do not make such long spawning migrations. It is noted that at least two isolated schools have been formed higher up the dams of the hydroelectric power stations on the Ob and the Irtysh. Today, the stock of semi-diadromous sturgeon is extremely low, but this school used to be the most abundant. The population of young fish in the middle-Ob school is of high density. But it has an extremely high mortality rate. The Chulym school of Ob sturgeon is in the best condition. Its population increases from the waters of two sturgeon and nelma reserves.     

The concentration of Mn,Cu, Zn,Co, B,Sr, Cd and Pb in alluvial soils of the Ob River (forest-steppe,southern taiga and central taiga)

Three areas of the Ob River floodplain (forest-steppe, southern taiga and central taiga) were investigated. The total amount of Mn, Cu, Zn, Co, B, Sr, Cd and Pb was identified. The same elements were identified in ammonium acetate buffer extract, 1N HCl extraction and Tamm’s and Grimm’s soil extracts. The basic amount of trace elements in the soils is in the potentially unstable form, in Tamm’s and 1N HCl extracts (up to 74% of the total amount). The geochemical spectra of the investigated elements’ concentration in the soils and meadow vegetation are given. The Ob floodplain is not polluted as it has not been affected by industry, and that is why natural mechanisms of these soils can be easily detected. The content reduction regularity of most of the trace elements and their unstable forms in the soils from the south to the north of the Ob floodplain is observed. The same regularity concerns plants in which Co, Mo, B, Sr and Cd contraction and Mn, Zn and Cu increase are detected.     

The study of terrestrial vertebrates of the Ob River basin

The paper describes the 300-year history of studying the terrestrial vertebrates in the Ob basin and the current state of researches into amphibians, reptiles, birds and mammals. We examine the role of the research centres in Western Siberia in studying the terrestrial vertebrates in the Ob basin, from the steppe in the south to the tundra in the north and the uplands of the Altai, Kuznetsky Alatau and Salair. We describe the degree of exploration of the terrestrial vertebrates in 11 Russian regions located in the area. The paper includes discussions of rare species, population, spatial distribution and man’s impact on the animals. We also indicate areas where there is insufficient study.     

Investigation of upper oligotrophic mires in the middle Ob basin (West Siberia)

The paper presents results of research into the upper ecosystems and convex forms of peat mires of moss (oligotrophic) type in the Ob basin area. We have determined four types of upper mire ecosystems, and have described their morphometric, botanical and hydro-chemical properties. These studies allow us to evaluate the structure and functioning of the upper mire ecosystems.     

The Effect of Overbank Flow in a Meandering River on its Conveyance and the Transport of Graded Sediments

A large-scale model hydraulic study of inbank and over-bank river flow, using a regular sinuous river channel with a mobile bed, was carried out in the Flood Channel Facility at HR Wallingford, UK. The selected sediment had a wide range of particle sizes present over the 'fine sand to coarse sand'range. Flow velocity, local and global sediment transport rates, and channel conveyance were all measured. The resulting bed forms were determined and used to explain the secondary circulation in the sinuous channel as well as the size sorting of the sediment. The paper gives an early overview of this major project.     

Spatial and temporal dynamics of suspended load at-a-cross-section: the lowermost Ebro River (Catalonia, Spain)

Suspended load dynamics were analyzed for the period 2007-2009 in a semi-meandering cross-section under different hydrological conditions. Samples were collected at four different points of the cross-section. During “low discharges” (≤600 m³/s) suspended load samples were collected at-a-monthly basis, whereas at “high discharges” (>600 m³/s) sampling was conducted intensively (at-a-daily basis during the first stages of the flood event). Results indicated that during low discharges, both organic and inorganic suspended load concentrations tended to be uniformly distributed across the fluvial section; but during high discharges, two distinct areas were found: an area extending from the “Inner-bank” to the “Channel centre” (Area-I) with higher suspended concentrations (organic and inorganic) than those recorded in the “Outer bank” (Area-II). This phenomenon was likely related to the formation of secondary flow velocity cells and the activation of new sources of sediment. In addition, a non-significant relationship between organic suspended load and water flow was observed in the outer-bank. At-a-monthly basis, the analysis of the suspended load showed the existence of an intra-annual cycle of the inorganic concentrations, with a progressive increase from October to March followed by a decrease from March to September. Nevertheless, the organic suspended load did not show any trend, being equally distributed along the year, suggesting that other sources of organic matter besides phytoplankton are predominant.     

Long-term studies (1871–2000) on acidification and recovery of lakes in the Bohemian Forest (central Europe)

This paper evaluates long-term changes in the atmospheric depositions of S and N compounds, lake water quality, and biodiversity at eight glacial lakes in the Bohemian Forest over the past 130 years. This time interval covers (i) the ‘background’ pre-acidification status of the lakes, (ii) a period of changes in the communities that can be partly explained by introduction of fish, (iii) a period of strong lake acidification with its adverse impacts on the communities, (iv) the lake reversal from acidity, which includes the recent status of the lakes. The lake water chemistry has followed—with a characteristic hysteresis—both the sharp increase and decline in the deposition trends of strong anions. Remarkable changes in biota have mirrored the changing water quality. Fish became extinct and most species of zooplankton (Crustacea) and benthos (Ephemeroptera and Plecoptera) retreated due to the lake water acidification. Independent of ongoing chemical reversal, microorganisms remain dominant in the recent plankton biomass as well as in controlling the pelagic food webs. The first signs of the forthcoming biological recovery have already been evidenced in some lakes, such as the population of Ceriodaphnia quadrangula (Cladocera) returning into the pelagial of one lake or the increase in both phytoplankton biomass and rotifer numbers in another lake.     

Spatial dynamics of farming practices in the Seine basin: methods for agronomic approaches on a regional scale

A research procedure is proposed which aims to analyse the agricultural spatial dynamics during the last thirty years using two levels of organisation of farming activity: the agricultural production system and the cropping system. Based on methods of statistical mapping and data mining, this procedure involves modelling the diversity of production systems and cropping systems (crop successions and sequences of cultural practices for each crop) in the form of classes independently of their localisation within the basin. It identifies homogeneous regions made up of groups of contiguous agricultural districts which exhibit similar combinations of production systems, crop successions or cultural practices during a given period of time. The results show a major increase in arable farms since 1970 at the expense of dairy farms and mixed cropping/livestock. This trend however appeared to be greatly spatially differentiated according to the agricultural districts, since livestock remained important on the edges of the basin, whereas it practically disappeared in its centre. The crop successions practiced in the basin and the cultural practices used on them also appear to be spatially differentiated, although the link to the production systems is not always clear. Thus it appears pertinent to combine the analysis of the two levels of organisation of the agriculture (methods of land use described by the concept of cropping system, and also the production systems into which the cropping systems fit) in the context of an environmental problem.     

A model for the frequency of extreme river levels based on river dynamics

A new model for predicting the frequency of extreme river levels is proposed which encapsulates physical knowledge about river dynamics. The central idea is the use of continuous time stochastic processes that use hydrological equations and ergodic theory to model extreme events, rather than relying on statistical fits of classical models to local maximum data. A simple example shows how changes in discharge characteristics change the extreme river level frequencies. Solutions are provided for special cases, and directions for more general techniques are provided.     

Bio-diversity and population structure of rove beetles (Coleoptera,Staphylinidae) in the flood plain habitats of the Ob and Irtysh basin

The study of Staphylinidae fauna in the Ob river flood plain was conducted from May to September 2010, and in the Irtysh flood plain from May to August, in 2013–2014. Pitfall traps together with hand collecting and soil sample sorting were used. The maximal bio-diversity (32 species, with Philonthus decorus Grav. dominating) and density of rove beetles were registered in the small-leaved forests of the Ob flood plain. In the Irtysh river flood plain rove beetles demonstrated maximal bio-diversity (16 species) in willow-shrub, Gymnusa brevicollis Grav., Philonthus albipes Grav. and Philonthus agilis Grav. dominating. Most Staphylinidae prefer wet and warm places, like an inner part of fluvial sediments or upper level of forest litter. In the forests’ ecosystems the peak of activity takes place between the beginning of June and mid-July, but it shifts to the end of summer in the wetlands of the Ob and Irtysh flood plain.