Synanthropization and species diversityof floodplain ecosystems of the Ob-Irtysh basin, Russia

Currently, the phytocenoses of the Irtysh floodplain are experiencing intense anthropogenic pressures due to the intensive development of the oil and gas industry, as well as the urbanization of the territory. This paper focuses on the structure and species composition of the 27 studied areas in the floodplain ecosystems of the Ob-Irtysh basin. As a result of the research, we found 111 species of vascular plants from 33 families in plant communities. The areas belong to meadows and forest vegetation are represented by (1) birch forests (33%), (2) pine forests (10%), (3) fir forests (8%), (4) aspen forests (4%) and (5) associations of meadows (45%). Furthermore, we conducted a comparative analysis of the studied phytocenoses according to the Drude scale. To determine the anthropogenic transformation of the flora and individual plant communities, we determined the synanthropization index (the ratio of synanthropic species to the total number of species). In the synanthropic flora fraction, we distinguished 45 species belonging to 12 families, with the most multispecies being Apiaceae, Scrophulariaceae, Compositeae, Ranunculaceae, Poaceae, Fabaceae, Plantaginaceae. The synanthropization index of the studied phytocenoses ranges from 6.6% to 81.2%. The largest number of synanthropic species occurs in meadow associations, the content of synanthropes is greater than 50%, the structure is becoming more superficial, and the productivity and stability of plant communities are changing. The study of the horizontal structure of grass stands of meadow phytocenoses makes it possible to find the variability of different years, the change of dominant species and the stability of the species composition. Currently, researchers are paying considerable attention to the analysis of the structure of the herbage, since its study is of great theoretical and practical importance in clarifying phytocenotic relations.

Ecological state of alluvial soils of floodplain landscapes under conditions of local pollution by hydrocarbons (Western Siberia)

The paper presents an analysis of field and experimental studies of the main physicochemical parameters of oil-contaminated soils of floodplain ecosystems of the middle taiga subzone of Western Siberia. The features and main regularities of their change in different pollution zones (epicenter - impact zone) are revealed. The state of the physicochemical parameters of technogenically contaminated soils is compared with background analogs. The most important groups of chemical compounds and elements that pose an environmental hazard are considered - oil and oil products, technogenic readily soluble salts (including their toxic compounds), the ways of their migration, transformation and accumulation in contaminated soils. General recommendations are given on the use of the discovered regularities in the technical maps of reclamation measures and the system for monitoring contaminated soils.

Length-weight relationships of three freshwater eel species from the floodplain ecosystems of northeastern Bangladesh

This study reports the Length-weight relationships (LWRs) of three freshwater eel species from the northeastern wetlands of Bangladesh. A total of 2684 specimens of Mastacembelus armatus, Macrognathus aculeatus and Macrongathus pancalus were sampled between in the months of June and December 2019 using different nets and eel traps at every 4 days working schedule per month. The calculated a values of the LWRs ranged from 0.008 to 0.020; b values ranged from 2.35 to 2.70, and r2 from 0.907 to 0.944. The lowest values of regression coefficient found for M. aculeatus and the highest for M. pancalus. All the regression parameters for LWRs found highly significant (p ˂ 0.001). These results will provide baseline information for sustainable management and conservation of the fisheries resources in the northeastern floodplain region of Bangladesh.

Rational use of floodplain ecosystems of the North

The purpose of the study is the spatial analysis of the factors of floodplain ecosystems and the calculation of rational use, through the calculation of technical and economic indicators and the calculation of the economic efficiency of haymaking. The assessment of the economic efficiency of the forage base was obtained based on the study of the grass stand and productivity of hayfields in five key areas of the Ob River floodplain, the study of soil properties, their qualitative characteristics necessary for understanding the soil fertility of floodplain ecosystems, on which land productivity depends. The spatial analysis of the rational use of the floodplain ecosystems of the Ob River was made in a semi-automatic way by decoding the Bing satellite image (the SAS Planet mapping and navigation program) in the Semi-Automatic Classification Plugin module in the QGIS geographic information system, the cartographic material was edited in the MapInfo Professional geographic information system.