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Wind erosion is one of the major environmental problems in semi-arid and arid regions. Here we established a transect from northwest (Tariat, Mongolia) to southeast (Xilingol, Inner Mongolia of China) across the Mongolian Plateau, and selected eight sampling sites along the transect. We then estimated the soil wind erosion rates by using the 137Cs tracing technique and examined their spatial dynamics. In the Mongolia section (from Tariat to Sainshand), the wind erosion rate increased gradually with vegetation type and climatic regimes; the wind erosion process was controlled by physical factors such as annual precipitation and vegetation coverage, etc. While in the China section (Inner Mongolia), the wind erosion rates of Xilinhot, Zhengxiangbai Banner and Taipusi Banner were thrice as much as those of Bayannur of Mongolia, although these four sites were all dominated by typical steppe. Besides the physical factors, higher population density and livestock carrying level should be responsible for the higher wind erosion rates in these regions of Inner Mongolia.
Damage to the environment and agricultural lands caused by water and wind erosion are phenomena well known in Slovakia. Wind erosion causes between 10 and 20% of damage and even more on the plains in the south west of the country. The work presents potential hazards and soil transport by wind in individual regions of the investigated part of Slovakia. While discussing the intensity of erosion the most important climatic, soil, geographical and anthropogenic factors affecting its results were considered.
There are various methods to assess soil erodibility for wind erosion. This paper focuses on aggregate analysis by a laser particle sizer ANALYSETTE 22 (FRITSCH GmbH), made to determine the size distribution of soil particles detached by wind (deflated particles). Ten soil samples, trapped along the same length of the erosion surface (150–155 m) but at different wind speeds, were analysed. The soil was sampled from a flat, smooth area without vegetation cover or soil crust, not affected by the impact of windbreaks or other barriers, from a depth of maximum 2.5 cm. Prior to analysis the samples were prepared according to the relevant specifications. An experiment was also conducted using a device that enables characterisation of the vertical movement of the deflated material. The trapped samples showed no differences in particle size and the proportions of size fractions at different hourly average wind speeds. It was observed that most of particles travelling in saltation mode (size 50–500 μm) – 58–70% – moved vertically up to 26 cm above the soil surface. At greater heights, particles moving in suspension mode (floating in the air; size < 100 μm) accounted for up to 90% of the samples. This result suggests that the boundary between the two modes of the vertical movement of deflated soil particles lies at about 25 cm above the soil surface.
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The paper presents some environmental impacts caused by two important factors of physical degradation of the soil, i.e., soil surface sealing/crusting phenomena and soil compaction. It can be concluded that despite numerous literature on the subject as well as the Authors' own data collected in model laboratory and field experiments, it is still difficult to judge to what extent the effects of those two processes are negative for both the soil environment and the plant growth.
The assessment of the density and cover of very scarce vegetation in dry habitats may create methodological problems. The variable area transect method (VAT ) is a potential labour-saving sampling method and an alternative to plot (quadrate) method. It allows for density estimation without the time-consuming studies associated with other plot-less density estimators. We used the method in a natural shrubland of Saxaul (Haloxylon ammodenderon C.A.M) to define optimum parameters include transect width and individual’s number to which, distance is measured. Three transect widths were chosen, 10-m, 15-m and 20-m and distances to the 3rd, 4th and 5th individual. Transect width affected the estimation, a 20-m width transect had the least relative bias (–0.5%), and a 10-m width sampling had the greatest bias (–20%). However, all methods underestimated the plant density. The most accurate estimation was with the 3rd plant distance and 20-m transect. As the VAT method is more efficient per unit effort in the field than the quadrate methods, it can be recommended for rapid assessment of desert communities density (like saxaul) especially when plants are dispersed at random.
The paper summarizes results of investigations done in 1999-2000 by 'several authors in Wielkopolska region, (western Poland) near Turew in young midfield shelterbelts and adjacent cereal felds. It was found that the soil organic matter content, as well as microbial and faunal biomass decrease gradually from the shelterbelt toward the field centre. The annual increase of carbon was assessed and possible sources of it (wind erosion, leaf fall, input of invertebrate faeces) considered. The results suggest, that excreta contribute significantly to total carbon input. The shelterbelts influence the biomass, density and composition of many soil and above-ground invertebrate taxa and individual size of animals occurring in bordering fields.
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