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Soil microorganisms may be both sensitive and resilient to various disturbances. The effects of a single stressor on soil microorganisms have been well studied, but only limited research has been carried out to test the effects of simultaneous action of diverse stressors. Soil samples were collected from a long-term polluted zinc and lead site and an unpolluted site. Modeling studies assumed spiking soils with five different concentrations of nickel (400, 800, 1.600, 3.200, and 6.400 mg Ni·kg⁻¹ dry weight soil) and their incubation under different humidity conditions (10%, 75%, and 120% of water holding capacity). We wanted to test if additional environmental disturbances have a different effect on microorganisms from polluted and unpolluted soils. The study showed that after 30 and 120 days of incubation, increasing Ni pollution inhibited microbial respiration rate (R), both in unpolluted and long-term metal polluted soils, irrespective of soil moisture. After 30 days of the experiment, microbial communities in both soils demonstrated a similar response to the additional toxicant. However, after 120 days of exposure to Ni, microbial communities from the unpolluted soil showed much higher inhibition of R than microbes from the polluted soils (p<0.001). The results might suggest that Ni co-tolerance mechanisms occurred in long-term metal polluted microbial communities.
В статье представлены исследования проведенные в районе садово-огородных участков в Сталёвой Воли, 7 км от металлургического комбината. Авторы предлагают предпринятие многих профилактических мероприятий с целью уменьшения отрицательного влияния промышленных эмиссий на овощи.
This study assessed the development of microbial biomass, basal respiration, and the activities of dehydrogenase, urease, and acid Phosphomonoesterase in sandy mine soils reclaimed for forestry and those developing under vegetation from natural succession. The mine soils contained significantly less organic C (Corg) and total N (Nt) than the natural forest soils. However, in some of them the microbial biomass and basal respiration attained values typical for the natural forest soils. The content of Nt proved to be the most important control on the microbial biomass, basal respiration, and the activities of dehydrogenase and Phosphomonoesterase in the mine soils. All the microbial properties were positively related also to Corg content. The activities of dehydrogenase and urease depended strongly on microbial biomass (Cmic). Hence, high activities of these enzymes were determined in soils containing high Cmic. The acid Phosphomonoesterase activity was also positively related to Cmic, but its activity was increased in the soils with low P contents.
Two plant species growing on calamine spoils (vicinity of Olkusz, S. Poland) were examined for their ability to accumulate metals. The plants in these pilot studies were Biscutella laevigata L., a rare plant that occurs in lowlands on zinc-lead mine spoils only in the vicinity of Olkusz, and Plantago lanceolata L. which is a common species in Poland. Concentrations of alkaline metals (Ca, K, Mg) and heavy metals (Cd, Fe, Mn, Pb, Zn) in soil and plants (shoots, roots) from two locations of calamine spoils 100 and 30 years old and control areas were determined. Soils from the mine spoils were alkaline (pH >7.4), with large concentrations of Ca and Mg. Concentrations of Cd, Pb and Zn in soil were up to 224 mg kg-1 3100 mg kg-1 and 78,000 mg kg-1, respectively. The amounts of exchangeable metals (1 M NH4NO3) were up to 9.51 mg kg-1 Cd, < mg kg-1 Pb, and 24.5 mg kg-1 Zn. Concentrations of heavy metals in plants from the calamine spoils and their distribution within plants depended on the species. B. laevigata accumulated heavy metals in roots (Cd) or shoots (Fe, Mn, Zn). P. lanceolata accumulated heavy metals mainly in roots. Maximum concentrations in roots and shoots of B. laevigata were 14.3 mg kg-1 Cd, 111 mg kg-1 Pb and 410 mg kg-1 Zn. P. lanceolata contained up to 65.6 mg kg-1 Cd, 157 mg kg-1 Pb and 2540 mg kg-1 Zn. Our data suggest that both species tend to exclude Cd, and P. lanceolata also Zn, present in large concentrations in the soil.
The objective of this study was to compare chemical and microbial properties of sandy mine soils under young Scots pine, silver birch, and mixed pine-birch forest stands. The measured properties included the contents of organic C (Corg) and total N (Nt), the Corg-to-Nt ratio, pH, microbial biomass, basal respiration, and activities of dehydrogenase, acid phosphomonoesterase, and urease. Community level physiological profiles (CLPPs) of soil bacteria were determined with BiologR test and genetic profiles with the DGGE method. Scots pine and silver birch did not affect the Corg and Nt contents in the studied mine soils. The soil under birch contained larger and more active microbial biomass than the soil under pine. Under the mixed stand, most of the microbial properties were intermediate between the pine and the birch stand. The DGGE profiling indicated different composition of soil bacteria under the birch stand compared to the other stands. Differences in CLPPs were less pronounced, probably due to functional redundancy of soil bacteria.
The aim of the study was to compare the feeding activity of soil fauna in seven temperate forests with the application of the bait-lamina method. Seven types of temperate forests located throughout Poland (East-Central Europe) were tested, ranging from dry pine forest with a typical poor quality soil to eutrophic riparian fresh deciduous forest. Each forest type was represented by five stands and all stands altogether represented natural gradient of soil fertility, texture and vegetation diversity. Despite clear diversification between the studied forest types according to a range of soil physicochemical properties and vegetation characteristics in addition to applying recommended measurement conditions for the method, we determined that the feeding activity of soil fauna did not differ between forest types. The activity of soil fauna did not depend on site botanical characteristics or any soil physical or chemical features, indicating that the bait lamina method was useless in measuring the feeding activity of soil fauna in temperate forest soils. Differences in the feeding activity of soil fauna might result from other environmental factors that influence soil fauna feeding activity in forest stands that were not measured here, i.e., soil temperature and humidity. The differences could also be attributable to the attractiveness of the bait substrate to soil fauna, which may be different in various soil conditions.
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