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The aim of the present study was to describe the distribution of xerothermic species of vascular plants in the lower San River valley and the relationship between their density and the intensity of selected environmental (natural and anthropogenic) factors. Xerothermic species occurred more frequently in the present valley floor compared to the glacial terrace. Within the present valley, the highest density was observed in the floodplain. The examined species also occurred more often on steep slopes of the valley, at the margins of the present valley terraces, and in the area of occurrence of aeolian sands. Moreover, a positive correlation has been found between the number of xerothermic species and the area of polyhemeroby ecosystems. The distribution of xero- and thermophilous species is determined by natural edaphic and geomorphological factors as well as anthropogenic ones (land use, lowering of the groundwater level as a result of river regulation).
In the paper, the methods for development of relational basis of topographical data and its processing into a form of maps of slopes, exposures and relative intensity of solar radiation, have been presented. The above mentioned process was divided into four stages: -gaining of data on terrain and their processing into a vector farm, -processing of data on terrain into a screen form, -calculation of slopes, exposures and relative intensity of solar radiation in screening system, -presentation of results in a graphical form, i.e. maps. Final results and maps of slopes, exposures and relative intensity of solar radiation will serve a verification of the following borders: agricultural-forest and sod-field.
This paper discusses the concentrations of heavy metals in soils at 6 sites of historic metal ore mining activities in the Sudety Mts. The main aim was to illustrate the difficulties in assessing if soil enrichment in metals originated from natural or anthropogenic factors. Such an ability to distinguish the difference is required by Polish legislation concerning the need for reclamation. Waste material collected from mine spoils usually contained very high amounts of some heavy metals (Cu, Pb, Zn, Ni, and As: up to 9940, 13600, 6150, 17600, and 40600 mg kg⁻¹, respectively). Also the soils considered as natural contained high concentrations of metals, with maximum values for Cu, Pb, Zn, Ni, and As: 3430, 2090, 3660, 4400, and 11500 mg kg⁻¹, respectively, usually exceeding many times the typical soil values and soil quality standards. Metal concentrations in the sesoils indicated strong spatial diversity. We concluded that the enrichment by heavy metals was apparently of mixed origin, both natural and anthropogenic, with unknown contributions by each factor. Additional data, including metal solubility, are needed for the assessment of the environmental risk and the need for reclamation.
Forests are one the main natural factors that regulate and determine climate, weather patterns and amount of CO2 of an area. With rapid industrialization and rapid urbanization there is a significant increase in deforestation and as a consequence rise in global mean surface temperatures. Rapid and unchecked cut down of forest cover has resulted in some of the worst disasters during the last decades. This paper focuses on studying the role of deforestation, its influence on climate change phenomena and its consequences in Pakistan.
Grassland degradation due to anthropogenic and natural factors and their interactions is one of the worldwide ecological and economic problems because it reduces grassland productivity and diversity and leads to desertification. The objective of this study was to assess the influence of protective enclosure on vegetation composition and diversity and plant biomass of an alpine degraded meadow. The experiment was conducted at center of Qinghai-Tibetan Plateau with two degraded (caused by overgrazing) alpine meadows: the lightly and severely degraded ones (LD and SD) and their enclosed areas with iron net (LDE and SDE, respectively). The areas 200 m × 150 m for each of four degraded alpine meadow treatments at average altitude 3,960 m a.s.l. were set for research. The lightly degraded plots were dominated by Scirpus distigmaticus (Kukenth.) Tang et Wang, Elymus nutans Griseb. and Oxytropis ochrocephala Bunge. The dominating plants in severely degraded plots were: Artemisia sieversiana Ehrhart ex Willd, Ajania tenuifolia (Jacq.) Tzvel, Lonicera minuta Batal. The results showed: (1) the vegetation cover of two degraded plots (LD and SD) has increased after taking the enclosure measures and the forbs dominated both plots. (2) Species richness has also increased in two enclosed degraded plots, respectively. There no significant differences in evenness and diversity between LD and LDE, and SD and SDE, respectively. (3) Enclosure may promote aboveground biomass, particularly grass and forb biomass in LD, and forb biomass in SD plots.
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