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Chrysophycean cysts and scales in paleolimnological studies
Bartošová, Kateřina ; Němcová, Yvonne (advisor) ; Škaloudová, Magda (referee)
This thesis deals with chrysophyte scales and stomatocysts as useful tool of paleoecological reconstructions in lake ecosystems. In the first part the geological physical and biological aspects of lake reconstructions are described. The second part contents information about chrysophyte taxa and their utilisation as paleoekological indicators. Chrysophyte microphosils include two major groups of siliceous indicator: stomatocysts and sculptured and ornamented species-specific scales. Using surface-sediment training sets, quantitative inference models have been constructed for eutrophication, acidification, air-born pollution, salinification, climatic change, and other environmental changes. This thesis represents a literature review.
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Forest vegetation changes in the Bohemian Forest during the second half of 20th century
Prach, Jindřich ; Kopecký, Martin (advisor) ; Sádlo, Jiří (referee)
Long-term forest vegetation changes were studied in the Bohemian Forest and its foothills. New vegetation relevés were taken at sites of typological plots established by forest engineers between 1955 and 1980. Data from 158 semi-permanent plots were analysed using modern statistical methods. The data show significant changes and homogenization of the vegetation. Ellenberg indicator values indicate eutrofication. Repeated measurements of soil pH suggest acidification, but the interpretation of these data is complicated by methodological problems. The forests under study exhibit high spatial variability. No main prevailing trend in vegetation changes was found. The changes are considered to be related to sulphur and nitrogen deposition and forest management. The influence of increasing age of forest stands seems to be unimportant. Discussed are not only vegetation changes and their possible causes but also the possibilities and limitations of using such old forestry data in botanical and ecological studies.
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Al forms in acidified surface waters - toxicity and trends
Šimková, Petra ; Hruška, Jakub (advisor) ; Hořická, Zuzana (referee)
This thesis deals with forms of aluminium occurring in acidified surface waters. Special attention is paid to inorganic monomeric aluminium, fraction, which has toxic effect on some species of aquatic and terrestrial biota. The thesis primarily focuses on the analysis of surface water, groundwater and soil water chemistry in the year-round and long-term monitoring. The practical took place on an experimental mountain basin Uhlířská, which is drained by river Černá Nisa. Uhlířská basin is located in the Jizera Mountains and represents the area which was significantly exposed to the acid atmospheric deposition in the second half of the 20th century. Long-term exposure to acid precipitation caused the acidification of soil and watercourses, forest degradation and deforestation of large parts of the basin. Decrease in pH and an increase in concentration of toxic aluminium also caused species depletion of aquatic ecosystems. Monomeric forms of aluminium were determined spectrophotometrically, the concentration of total aluminium was determined by the method of flame atomic absorption spectrometry (FAAS), in case of low concentration electrothermal atomic absorption spectrometry (ETAAS) was used. Five forms of aluminium were obtained - Altot, AlAS, Alm, Alo and potentially toxic Ali. Appart from...
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An acidification of fresh waters is not over
Beneš, Filip ; Tátosová, Jolana (advisor) ; Hardekopf, David (referee)
Acidification of freshwaters is a problem of many areas over the northern hemisphere from the half of the 20th century. It has been caused by industrial factories discharging emissions of sulfur and nitrogen oxides, from which originate acids by the photochemical reactions in the atmosphere. Acidic atmospheric deposition has caused disappearance of fish and the most aquatic organisms in streams and lakes. Acidic atmospheric deposition has also washed up not only the buffering basic cations (Ca2+ , Mg2+ , Na+ , K+ ), but also toxic aluminium (Al3+ ) ions from soils into the freshwaters. The maximum levels of emissions of sulfur and nitrogen oxides were observed in 1980s and since that time the emissions of sulfur and nitrogen oxides significantly dropped down. However, the recovery from acidification is not as fast as it could be expected. It is impeding by several processes. One of them is hysteresis or saturation of soils by sulfur and nitrogen, which are slowly washing up into the freshwaters in forms of sulfates and nitrates now. Another process is the oligotrophication of lakes, when the important nutrient - phosphorus - is precipitating by aluminium. There is the lack of food for organisms after that. Another processes slowing down the recovery from acidification could be bad forest management...
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Trends in composition of atmospheric precipitation and deposition in Europe
Šimková, Petra ; Hůnová, Iva (advisor) ; Maznová, Jana (referee)
This bachelor thesis describes the historical development of emissions and their associated composition of atmospheric precipitation and atmospheric deposition in Europe. It is the work with review character, which summarizes and evaluates current knowledge of the majority components of atmospheric deposition. It relies particularly on articles and a summary reports of monitoring networks devoted to the large time horizon. At the beginning part of this work are defined the major components of atmospheric deposition. In another part is described composition of atmospheric precipitation, sampling dry and wet deposition and subsequent chemical analysis. The main part is devoted to evaluate the development of emission and sputtering of the main trends of acidifying compounds, and basic cations in Europe. Emission and deposition trends are divided into time periods, which were defined in relation to the development of historical, political or economic situation. Another criterion in the evaluation of trends in the composition of atmospheric precipitation and atmospheric deposition was the State's geographical position within Europe. There are summarized the results of studies on the deposition trends across Europe, but the main attention is devoted to the differences between Western and Eastern Europe...
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Phytoplankton of the Tatra lakes: factors influencing taxonomic composition and biomass
Červenková, Lenka ; Nedbalová, Linda (advisor) ; Štefková, Elena (referee)
The aim of this diploma thesis was to describe species composition and biomass of phytoplankton in the Tatra Mountains lakes (Slovakia, Poland) and environmental factors influencing them. The surface layer of 89 lakes was sampled in September 2004. Flagellates from Chrysophyta, Dinophyta and Cryptophyta most frequently dominated the phytoplankton biomass. Lake in the same valley usually differed in their dominant taxonomic group as a result of different lake morphometry, catchment type and detailed geological structure. Based on the level of phytoplankton biovolume, the majority of lakes were ultraoligotrophic and oligotrophic, however, mesotrophic and even eutrophic conditions were recorded in some forest and meadow lakes. An allometric relationship between phytoplankton biomass and chlorophyll a was revealed. Specific chlorophyll content did not differ among taxonomic groups. Altogether 233 species were determined, the most diverse group were Chlorophyta. Species richness of lake was 3-46 and it was negatively correlated with altitude and positively correlated with lake area. The majority of species were rare both in term of biomass and number of lakes occupied by a particular species. Average local species biomass was positively correlated with regional distribution. The similarity of species...
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Fish and benthos of the Černá Nisa stream and their contamination by metals in the period of recovery from acidification
Burdová, Lucie ; Hořická, Zuzana (advisor) ; Slavík, Ondřej (referee)
The aims of the thesis were to compare chemistry of the Černá Nisa stream in the Jizera Mountains (Northern Bohemia, Czech Republic) at the end of the era of strong anthropogenic acidification (in the mid-1990s) and in the period of the recent intensive chemical and biological recovery from acidification, and to study the present biota of the stream. During the year 2008, physical and chemical parameters of the water were studied, the species and age composition of ichthyofauna, and the quality and quantity of macrozoobenthos - the main component of the food for fish. Special attention was paid to the content of toxic metals (Be, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, Hg) in the water, main representatives of benthic organisms, and in selected tissues of brook charr. The comparison of the water chemistry with results from the years 1994, 1996, and 1997 showed a decrease in acidification, despite the unstable chemical climate during the seasons, and sulphate and nitrate concentrations still high. Since the mid 1990s, the stream has been inhabited by a stable population of brook charr (Salvelinus fontinalis), a non-native, highly acid-tolerant species, which is now dominating there. At present, also a stable population of a native species, common minnow (Phoxinus phoxinus), occurs in the stream....
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