Forest-steppe Region Research Articles

An agroecological estimation of field protecting wood strips in view of their age in forest Steppes of the Middle Volga Basin

An agroecological estimation of wood strips is given on the basis of the field and expedition researches of the period of 1978–1997. Changes of ornitho‐ carbidephauna, an acqua‐physical and agroecological properties of dealkalined black soil in foreststeppe region of the middle Volga basin are illustrated with consideration of the age of wood strips. A higher resistability to adverse factors (droughts, pests) of agrophytocenoses is marked on the fields protected by wood strips in comparison with open space fields.

Variability in aerosol and air ion composition in the Arctic spring atmosphere

Systematic measurement results of aerosol dispersity in the size range from 0.004 to 10 μm in diameter, element composition, and the mobility spectrum of atmospheric ions in the range from 0.00032 to 5 cm 2/V s in the surface atmospheric layer at Zigler Island (Western Arctic, Franz–Joseph Archipelago, March–April 1994) are presented. A comparison is made with data obtained using similar methods and instruments at Wrangel Island (Eastern Arctic, March–April 1985), in Antarctica (Molodezhnaya station, January–May 1983), over the Pamir mountains (Fedchenko glacier, September 1989) and in the vicinity of Moscow (Obninsk, April–May 1994)). The form and variability of the aerosol size and air ion mobility spectra at different regions of the Arctic and Antarctic, as well as in mountain and forest steppe regions, do not differ significantly. The stratification of the atmospheric boundary layer and wind speed are the main factors of variability of the arctic aerosols and ions. Inflows of air from the mainland do not change these positions.

The vegetation of the forest-steppe region of Hustain Nuruu, Mongolia

The vegetation of a forest-steppe region in Hustain Nuruu, Mongolia, was studied by a phytocoenological approach. Eleven plant communities were recognized, comprising four steppe communities, two meadow communities, a tussock grassland, two shrub communities, a scrub community and a woodland community. The botanical and ecological characteristics of the different communities are discussed, with reference to the existing classification of Mongolian plant communities. Analysis of the present data indicates that a refinement or extension of the classification system is desirable, especially concerning the steppe(-related) communities. Discussion of the relative distribution of steppe and forest reveals that in the relatively dry location of Hustain Nuruu grassland and shrubland dominate the natural vegetation (88% of the area). Forest covers ca. 5% of the area, it is limited to sites where ground water is within rooting depth: north slopes above 1400 m (Betula platyphylla woodland) and along erosion gullies (fragmentary Ulmus pumila gallery woodland). Under natural conditions forest cover might reach 12%, but it is speculated that wild ungulates could maintain its extension at a lower level. The importance of forest is greater in forest-steppe regions with higher rainfall, but the factors determining the distribution of grassland and forest are expected to be similar.

Turbulent exchange over a surface with chessboard-type inhomogeneities

The results of an experiment carried out in the summer of 1988 in the forest-steppe region of the USSR are given. The aim of the experiment was to study turbulent exchange between the atmosphere and a non-homogeneous underlying surface consisting of a “patchwork quilt” of agricultural lands sown with different crops (hereafter called chessboard-type inhomogeneities). Simultaneous measurements of turbulent fluxes of heat, momentum and humidity by the eddy-correlation methods and also the measurements of the mean wind velocity and temperature are described. The values of turbulent fluxes calculated from the profile measurements are in good agreement with those obtained from the eddy-correlation measurements. Thus it may be concluded that the universal functions of Monin-Obukhov similarity theory (determined from measurements over a flat and homogeneous underlying surface) pertain also to a non-homogeneous (chessboard-type) underlying surface.

USSR: Law on Measures to Ensure High and Stable Yields in the Steppe and Forest-Steppe Regions

USSR: Law on Measures to Ensure High and Stable Yields in the Steppe and Forest-Steppe Regions