|
|
Landscape-scale changes in central Europe around the Pleistocene-Holocene transition and the Anthropocene
Prach, Jindřich ; Pokorný, Petr (advisor) ; Kuosmanen, Niina Irina (referee) ; Roleček, Jan (referee)
This thesis investigates the dynamics of the central European landscape. Four case studies, exploring two key periods of environmental transformation: Late Glacial and the Anthropocene, are included. All case studies are connected by the spatial scale of interest: the landscape scale. This scale is targeted not only by the spatial extent of the sampling, but by the essence of the issues investigated, as broadly described in the introduction. The studies use disparate methods and different contexts, which helps to approach such a complex phenomenon - the landscape and its formation. The included studies are dealing with the Last Glacial landscape and vegetation by (1) comparing pollen records using modern analogues (here from Yakutia) and argues that the change at the Late Glacial/Holocene transition may not have been as great as previously thought, because at least somewhere forests may had existed during the Last Glacial being supported by permafrost melting. A follow-up study (2) explores how permafrost melting, i.e., thermokarst processes, generated an entire lake landscape whose remnants unexpectedly largely persist in the Třeboň region (southern Czech Republic) to recent times. This is followed by (3) the use of a detailed palaeoenvironmental record of the discovered lakes and their contexts...
|
|
|
Factors determining plant species diversity and species composition in suburban landscape
Čepelová, Barbora ; Münzbergová, Zuzana (advisor) ; Roleček, Jan (referee)
Studium vegetace v příměstské a postindustriální krajině je na okraji zájmu, ačkoliv tyto oblasti tvoří stále významnější část území Evropy. Práce zachycuje diverzitu a druhové složení vegetace příměstské krajiny u města Kladna pomocí pravidelné sítě o 242 fytocenologických snímcích. Zkoumá vliv abiotických faktorů a struktury krajiny na zaznamenanou vegetaci jako celek, i na jednotlivé typy - polní, nelesní, lesní. Vegetace příměstské krajiny je relativně druhově bohatá, do značné míry určená využitím a strukturou krajiny, význam mají i abiotické faktory. Powered by TCPDF (www.tcpdf.org)
|
|
| |
|
|
Relative pollen productivity estimates of main tree taxa of Central Europe in model area Křivoklátsko.
Fořtová, Pavlína ; Abraham, Vojtěch (advisor) ; Roleček, Jan (referee)
Pollen spectra found in sediments enable the research of quantitative changes in vegetation composition in the past. The fact is conditioned upon assumption of unchangeable linear relationship between abundance of pollen and the vegetation that is responsible for its production. Calibration of this relationship is experimentally performed on modern pollen samples and current vegetation. Relative pollen produktivity etimates (PPEs) represents basic parameters for the conversion of proportional pollen data into the vegetational ones. Their knowledge is indispensible for the quantitative vegetation restoration and for the simulating of the processes of pollen dispersion and deposition. PPEs estimation is performed by ERV model which corrects nonlinear relationship of proportional pollen and vegetation data back to the linear relationship. ERV model estimates PPEs values together with values of pollen background by maximum likelihood method. Knowledge of PPEs of main tree species is crucial for the understanding of processes which takes place on the level of landscape scale. Model area of Křivoklátsko was selected due to its high forest coverage and tree diversity. Twenty-four localities were chosen upon stratified random selection. Moss polsters containing modern pollen loading were taken and detailed...
|
|
|
Environmental gradients during Late Glacial in Central Europe
Petr, Libor ; Sádlo, Jiří (advisor) ; Magyari, Eniko (referee) ; Roleček, Jan (referee)
The Lateglacial and Early Holocene are key periods with respect to the understanding of the present-day vegetation and environment. An interdisciplinary approach is important for the study of these changes. Only by interlinking biological and geoscience evidence can we obtain a more comprehensive picture of this key period. It is not possible to interpret any pollen spectrum in the sedimentary record without knowledge of the history of the locality and its vicinity. Rapid climate changes had a crucial effect on the environment and vegetation. Continentality of the climate and a deficit of precipitation amplify the effect of local conditions. Vegetation, as in the case of vertebrates and molluscs, comprises a combination of species of a continental steppe, mountain biotopes and disturbed habitats. This facilitated contact among species and populations that are biogeographically separated at present. Vegetation of the Lateglacial period in the Czech Republic ranges in character from frost barrens in the mountains, through steppe-tundra vegetation at medium altitudes to a continental steppe in the lowlands and pine woodlands constrained to a moist floodplain. The Western Carpathians were covered by a taiga. In the Pannonian Lowland, there were open forests with conifers and broadleaved woody plants....
|
|
|
Influence of local woody species coverage on herb vegetation on a small spatial scale
Kubát, Miloš ; Vojta, Jaroslav (advisor) ; Roleček, Jan (referee)
English abstract This work aims on influence of local coverage of woody layer on understorey herbs. Expansion of woody species into semi-natural grassland ecosystems is accompanied by increase of local coverage of woody layer. This process leads to changes of environmental conditions in understorey, that is followed by extinction of heliophillous herb species. This works deals with this phenomenon on a small spatial scale. The research took place near former village Tocov, situated in an abandoned landscape in Doupovské hory. This locality is typical example of woody species expansion into species rich grassland. Here, 399 phytocoenological relevés were collected. These relevés are ordered into triplets, that make triangles. There are local coverage of woody layer measured for each relevé. Impact of this variable was tested in two sizes of the observation window. Single relevés present microsites, while whole triplets present sites, where variability of local covarage of woody layer, leading to variability in herb layer, could be distinguished. Number of herb species is linearly negatively correlated with local coverage of woody layer on a smaller scale of single relevés. In whole triplets, increase of local coverage of woody layer, during early stages of woody species expansion, doesn't lead to decrease of...
|
|
|
Vegetation of fir- and calcicolous beech forests of the Czech Republic
Boublík, Karel ; Sádlo, Jiří (advisor) ; Roleček, Jan (referee) ; Ewald, Jörg (referee) ; Walentowski, Helge (referee)
Boublík K. (2009): Vegetation of fir- and calcicolous beech forests of the Czech Republic. - Ms., 104 p. [PhD thesis; depon. in: Library of the Department of Botany, Faculty of Sciences, Charles University, Prague] The thesis proposes Braun-Blanquet phytosociological classification of calcicolous beech forests and fir forests of the Czech Republic. Calcicolous forests dominated by Fagus sylvatica (Fagion, Cephalanthero-Fagenion) were defined with the help of two approaches: (i) selection on the basis of correspondence of species composition with an expert delimited species group and (ii) the formalized and supervised Cocktail method. In the case of the Cocktail method, the definitions of associations were created by combinations of sociological species groups using logical operators. Dominance of single species was included in the definitions of associations. Only one association (Cephalanthero-Fagetum) was distinguished. This association usually occurs on limestone, calcareous sandstone and calcareous sandy marlite. However, it can be found also on basalt and phonolite. TWINSPAN analysis distinguished three vegetation types within Czech calcicolous beech forests which are interpreted as subassociations of Cephalanthero- Fagetum: (i) Cephalanthero-Fagetum seslerietosum caeruleae occurring on...
|
|
|
Factors determining plant species diversity and species composition in suburban landscape
Čepelová, Barbora ; Münzbergová, Zuzana (advisor) ; Roleček, Jan (referee)
Studium vegetace v příměstské a postindustriální krajině je na okraji zájmu, ačkoliv tyto oblasti tvoří stále významnější část území Evropy. Práce zachycuje diverzitu a druhové složení vegetace příměstské krajiny u města Kladna pomocí pravidelné sítě o 242 fytocenologických snímcích. Zkoumá vliv abiotických faktorů a struktury krajiny na zaznamenanou vegetaci jako celek, i na jednotlivé typy - polní, nelesní, lesní. Vegetace příměstské krajiny je relativně druhově bohatá, do značné míry určená využitím a strukturou krajiny, význam mají i abiotické faktory. Powered by TCPDF (www.tcpdf.org)
|
|
| |
guest ::
