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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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Numbers of non-native waterfowl species in Europe
Hodková, Veronika ; Musil, Petr (advisor) ; Šťastný, Karel (referee)
The Thesis is treating the spreading of non-native waterfowl species into new ecosystems and factors, which influence that process. The impact of selected eco-geographic characteristics on the species diversity and on the numbers of non-native waterfowl individuals was analyzed on the results of the International Waterbird Census. Further, the influence of those characteristics on the numbers and population trends of selected 11 species of the Anatidae family in 17 European countries was assessed. The highest non-native waterfowl species diversity was recorded in countries of the Atlantic coast, i.e. France, Germany, the Netherlands, Belgium and also Switzerland. The main positive influence on their numbers makes the density of population and species diversity of wintering waterfowl. As to the number of non-native species individuals the main impact is produced by both, species diversity and the given latitude, too. It means that the largest number of individual exist in northern countries - Great Britain, Sweden, Germany and the Netherlands. Similar main influences have been traced with the family Anatidae, too, which have received special attention in the analysis, as it shows the highest number of non- native species. As to the main eco-geographic characteristics, having impact on the growth or...
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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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Development of permanent grassland after sowing arable land
CÁBOVÁ, Lenka
Three unnamed locations were monitored in the eastern part of the Šumavské and Novohradské Foothills in the Southern Bohemia, the district of Český Krumlov. An arable land was grassed with permanent clover-grass mixture consisting of seven grass species and one clover species. The aim of my bachelor thesis was to evaluate the development of grasslands after sowing of the arable land. It was very interesting to see how the vegetation is getting involved with and gradually being enriched with other species. The average coverage rate of the herb layer, the average number of species in the herb layer and the average forage value were monitored. At the time of the phytosociological monitoring, the vegetation at the site was six years old at the location 1, or three years old at the locations 2 and 3. The phytosociological mapping was performed to capture the spring, summer and autumn aspect. By evaluating the results, it was found out that the oldest site 1 has the lowest coverage rate of grasses and a too high coverage rate of clovers and herbs. This site also shows the lowest average number of species and foraging value compared to other locations. All three sites have shown an enormous spreading of the dandelion in the vegetation. The coverage rate of the sown grass species decreased in almost all localities, except for the meadow fescue at the location 2 and the smooth meadow-grass on the location 1. The coverage rate of the sown red clover has increased only at the location 1. The total disappearance of Italian rye-grass from the vegetation was recorded at all three sites. The monitored sites are still very young, so we can expect a further stabilization and vegetation succession in approximately 10 years. It is evident from the obtained results that the species composition of the sites is influenced both by the manner of management (mowing), by the age of the vegetation, by its establishment and also by succession.
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