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Distribution and pattern morphology of pseudomorphs of thermal-conctraction-cracks features in Austria
Dufek, Jaroslav ; Křížek, Marek (advisor) ; Margold, Martin (referee)
During the cold Pleistocene episodes, the territory of Austria was at the forefront of nearby Alpine glaciation. The unglaciated area of Austria was part of the Central European periglacial zone, in which permafrost developed. The distribution of Upper Pleistocene permafrost, its character, but also its time classification in the western part of the Pannonian Basin is still unclear. It is also because ideas about the characteristics of Upper Pleistocene permafrost in this area have so far been based mainly on indirect biological or lithological records such as pollen grains, malacofauna snails, or loess-paleosol sequences. Until now, the evidence of direct geo-indicators of paleo-permafrost has been relatively limited, with unique relict frost-wedges, cryoturbations, or sporadic remains of thermokarst lakes depressions and pingos. The results present a new database of relict frost-wedges in Austria, which was created based on published literary sources, but mainly based on aerial imaginary available on Google Earth Pro. The results significantly expand (by hundreds of localities) the existing knowledge about the occurrence of relict frost-wedges, which have so far been located in Austria purely on the basis of excavated profiles and soil probes. The found polygons of frost-wedge pseudomorphs are an...
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Forest evolution in Central Europe during the Holocene periode
Švábová, Barbora ; Šefrna, Luděk (advisor) ; Matějček, Tomáš (referee)
The work deals with the forest as an ecosystem where relationships take place, which are influenced by abiotic and biotic factors. Great attention is paid to the climate, which affects not only the distribution of biomes. Its constant changes have an impact on the species composition of forests and human society. By the effects of the climate, the Holocene period was divided into sub-stages. Man also played a significant role in the conversion of the central Europe forest and changes it even now. That is why this work devotes a considerable part of it to this influence. Great changes of the forest began with the emergence of agriculture, which was the first impulse for the beginning of deforestation. Examined are the ways of prehistoric and modern economy. With the loss of trees came an idea of protecting the forests. As an example of possible further effect on the forest, the influence of some pathogens is presented.
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Paleoenvironmental record of carboniferous lacustrine deposits of central and western Bohemian basins: analysis and korealiton of mineral and biogenic proxies
Lojka, Richard ; Hradil, David (advisor) ; Hladil, Jindřich (referee) ; Janočko, Juraj (referee)
Ph.D. thesis represents summary of multidiciplinary palaeoenvironmental and palaeoclimatic research of the most significant Late Pennsylvanian lacustrine horizon of the central and western Bohemian basins - the Malesice Member of the Slaný Formation. Two cores from new shallow drills, situated 80 km apart, were analysed. Multidisciplinary approach is based on description of lamination structure and periodicity; mineral and isotopic composition of autigennic carbonates, namely siderite; compositiona of detrital minerals including clay mineral assemblages; and composition of autochthonous and allochthonous organic particles including palynospectra. Detailed analysis of drill cores lead to the identification of individual phases of lake development linked with lake-level fluctuation and water-column stratification, which were driven by a sume of precipitation and its seasonal distribution. Changes in precipitation also affected compostion and density of vegetational cover in the lake surroundings, weathering intesity of source rocks and degradation of organic matter in the drainage basin, and so precipitation affected final grain-size and composition of detrital material deposited in the lake. Beside common environmental signatures at both studied sites, there are also significant...
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Forest evolution in Central Europe during the Holocene periode
Švábová, Barbora ; Šefrna, Luděk (advisor) ; Matějček, Tomáš (referee)
The work deals with the forest as an ecosystem where relationships take place, which are influenced by abiotic and biotic factors. Great attention is paid to the climate, which affects not only the distribution of biomes. Its constant changes have an impact on the species composition of forests and human society. By the effects of the climate, the Holocene period was divided into sub-stages. Man also played a significant role in the conversion of the central Europe forest and changes it even now. That is why this work devotes a considerable part of it to this influence. Great changes of the forest began with the emergence of agriculture, which was the first impulse for the beginning of deforestation. Examined are the ways of prehistoric and modern economy. With the loss of trees came an idea of protecting the forests. As an example of possible further effect on the forest, the influence of some pathogens is presented.
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