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Concept of critical loads of sulphur and nitrogen for ecosystems and modelling of soil chemistry and vegetation species composition of ecosystems affected by acidification and nutrient degradation for selected sites in the Czech Republic
Lebedová, Michaela ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
The knowledge of the emission history and deposition trends of the main pollutants is key to understanding changes occurring in ecosystems. High levels of sulphur (S) and nitrogen (N) deposition, which peaked in the Czech Republic in the 1970s and 1980s, have caused significant acidification and damage to forest ecosystems. Due to the political and economic changes in the 1990s, there was a significant reduction in emissions and an improvement in the conditions of forest soil. Futures ecosystems development and recovery are affected primarily by climate change and still excessive nitrogen loads. To model the future development of ecosystems affected by acidification and nutrient degradation in the Czech Republic the dynamic model VSD+ Studio in combination with the vegetation model PROPS was used in this work. Two forest catchments of the GEOMON network (Liz and Uhlířská) were selected as model sites. The catchment areas significantly differed in the historical sulphur and nitrogen deposition loads. The results indicate that excessive depositions of S and N between 1970 - 1990 caused significant soil acidification and reduced the level of base saturation in both monitored locations. There is also a decrease in the C:N ratio and organic carbon content in the mineral soil. The vegetation model PROPS...
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The ability of plants to indicate abiotic environmental conditions
Lebedová, Michaela ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
The occurrence of different plant species is influenced mainly by individual environmental factors such as light, heat, soil reaction or nutrient content. The knowledge of the relationships between the plant species and the mentioned ecological factors, allows us to estimate the ecological properties of the habitats in which these species grow without the need of direct measurements. The aim of this thesis was to review the literature on the ability of different plants to indicate abiotic environmental conditions and to verify it on selected soil properties (soil nitrogen and phosphorus content, soil reaction) at sites where both soil sampling and analysis and phytocenological relevés were collected. Tabulated Ellenberg's indicator values were assigned to recorded species from 14 catchments of the GEOMON network. The tightness of the relationship between the indicator values and the measured data was examined in several soil layers defined as: L, FH, 0-10, 10-20, 20-40 a 40-80 cm and phytocenological relevés of different size: A - 400 m2 , B - 40 m2 a C - 4 m2 . The results showed that the data correlated best in the soil layer FH and the strongest relationship was found between the average Ellenberg's indicator values from phytocenological catchments C with an active soil reaction. Keywords:...
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Conscription of electricity from solar radiation and its impact on manufacturers
LEBEDOVÁ, Michaela
Main topic of this thesis is implementation of a new levy on electrocity generated by solar radiation, so called solar tax, which was imlemented in 2011 to affect all solar power stations starting their operations between years 2009-2010. The main aim of this thesis is to evaluate the impact of the solar tax on providers of this type of electrocity, who were not aware about it in advance before realization of their projects. In the first part of the thesis there is a description of the basic terminology regarding renewable energy and its forms, solar energy and discharge of electricity from solar radiation. The second part focuses on the characteristics of solar power Mříč a comparison of actual and projected costs and revenues after the introduction of solar tax. For selling prices the tax is set 26%, while for the green bonuses it is 28%. Results suggest that in the year of implementation of the solar tax the true expenses for providers were much higher compared to their expected values, which led to practically zero profits.
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