National Repository of Grey Literature 45 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Characterization of peat
Freithová, Štěpánka ; Mikšík, František (referee) ; Kotlík, Josef (advisor)
Peatlands are considered to be valuable ecosystems on the Planet and play an important role in many processes globally likewise and in the landscape. They are important for maintaining a global biodiversity, play an important role in landscape hydrology and can be a source of drinking water. They can help minimize floods and contribute to climate change mitigation. The peat bogs are one of the largest terrestrial carbon reservoirs. They have been storing carbon for centuries. Many of peat functions are affected due to human activities. It can result into release of greenhouse gases into atmosphere and the excretion of organic carbon into watercourses. The subject of the thesis is understanding of the mechanisms of water binding in peat and exploring possible dependencies within the depth profile of the peatlands using thermal analytical methods, more preciously using thermogravimetry (TG) and differential scanning calorimetry (DSC). The stability of water molecule bridge (WaMB) was investigated. It was found out that the minimum temperature required for WaMB abatement decrease and the whole structure becomes less stable with increasing peat layer depth. Water release processes were evaluated with the meaning of the TGA measurements. A decreasing trend in the degradation of thermolabile substances and an increasing trend in thermostable substances within the peat profile were observed.
Společenstva korýšů a vířníků v přirozených a revitalizovaných rašeliništích
Pfeifer, Lukáš
The theoretical part of the diploma thesis evaluates the current state of peatlands in the Czech Republic. Peatland were affected by drainage and the subsequent drying due to the peat extraction. There is the effort to restore these localities to their natural character and to protect them at present. The practical part evaluates species composition of mi-crocrustaceans and rotifers of monitored natural and restored peatlands in the Ore Mountains and Šumava. A total of 39 taxa of rotifers and planktonic crustaceans was found. The impact of restoration on these communities was evaluated based on differ-ences in species composition.
Changes of natural organic substances within hydrological extremes in headwater areas
Bejčková, Marie ; Matoušková, Milada (advisor) ; Vlček, Lukáš (referee)
Diploma thesis is focused on changes of natural organic matter within hydrological extremes in headwater areas of the upper Vydra. The increace in these concentrations and increased transport to surface waters negatively affect the environmental and social environment. The main aim of this work is to analyse the amount and variability of organic metter in relation to selected runoff events with clarification of these relationship. The change in the amount of concentrations and variability of Dissolved Organic Carbon (DOC) was evaluated with respect to the preconditioning of the catchment (over a period of 14 days) and the influence of hydroclimatic conditions during the episodes. The dependence of each variable on DOC concentrations was also examined. The dependence of parameters (water temperature, conductivity, flow rate, pH, Dissolved Oxygen, Dissolved Organic Carbon concentration) within the campaigns and the subsequent similarity of the profiles were also investigated. The data for this work were provided by the Department of Physical Geography and Geoecology, Faculty of Science, Charles University. The evaluating of relationship and processes was determined, for example, using Principal Component Analysis (PCA Analysis), hysteresis loop or Pearson's correlation coefficient. The greatest...
Carboniferous tropical ecosystems of euramerican province
Frojdová, Jana ; Opluštil, Stanislav (advisor) ; Sakala, Jakub (referee)
This thesis deals with the tropical terrestrial ecosystems of Late Carboniferous (Pennsylvanian) time. It is especially focussed on description of the Carboniferous tropical forest and its components. Introductory parts of the thesis deal with the general characteristics of Carboniferous period, including fauna and flora, distributions of continents and how was the climate of this period. Second part follows the characteristics of particular components of the Carboniferous tropical forest, i.e. of individual plant groups and genera, and their ecological demands. Characterised are plants and their assemblages in tropical lowlands as well as in upland areas, rarely preserved in sedimentary record. In the next part I characterise the dynamics of the forest of Carboniferous tropics and discuss potential mechanisms which controlled the floristic changes including plant extinction. The role of climate changes, which had great influence on vegetation, is discussed as the possible main control. In the separate chapter I describe extinction of arborescent lycopsids. Key words: ecosystem, tropical forest, lowland, climate changes
Ombrotrophy and minerotrophy of acidic wetlands - ecological and environmental indicators
Hanousková, Andrea ; Neustupa, Jiří (advisor) ; Šťastný, Jan (referee)
In this thesis I focus on different aspects of two basic types of peatlands - ombrotrophic bogs and minerotrophic fens, that differ in the source of their water supplies. In case of the bogs, all the moisture comes from precipitation, the fens are in varying degrees supplied with water from the mineral soil and bedrock. This concept is based on the assumption that hydrological conditions are essential for other properties of acidic wetlands, especially for vegetation, which is still the subject of discussion. Therefore I mention different gradients of peatlands (pH, nutrients and minerals) and important processes (succession, accumulation of peat) with regard to their relation to minerotrophy and ombrotrophy and I discuss their importance for the entire ecosystem. In the second part of my thesis, I focus on the algal assemblages in peatlands, which despite its immense diversity often form a neglected component of these ecosystems. The structure of algal communities vary in space and time under the influence of various factors, including, among others, ombrotrophy and minerotrophy. Powered by TCPDF (www.tcpdf.org)
Characterization of peat
Freithová, Štěpánka ; Mikšík, František (referee) ; Kotlík, Josef (advisor)
Peatlands are considered to be valuable ecosystems on the Planet and play an important role in many processes globally likewise and in the landscape. They are important for maintaining a global biodiversity, play an important role in landscape hydrology and can be a source of drinking water. They can help minimize floods and contribute to climate change mitigation. The peat bogs are one of the largest terrestrial carbon reservoirs. They have been storing carbon for centuries. Many of peat functions are affected due to human activities. It can result into release of greenhouse gases into atmosphere and the excretion of organic carbon into watercourses. The subject of the thesis is understanding of the mechanisms of water binding in peat and exploring possible dependencies within the depth profile of the peatlands using thermal analytical methods, more preciously using thermogravimetry (TG) and differential scanning calorimetry (DSC). The stability of water molecule bridge (WaMB) was investigated. It was found out that the minimum temperature required for WaMB abatement decrease and the whole structure becomes less stable with increasing peat layer depth. Water release processes were evaluated with the meaning of the TGA measurements. A decreasing trend in the degradation of thermolabile substances and an increasing trend in thermostable substances within the peat profile were observed.
Vyhodnocení obnovy těženého rašeliniště Borkovická blata po revitalizaci
CHROUSTOVÁ, Lucie
The aim of this thesis was to evaluate the recovery of cutover peatland Borkovická blata whose part was leaved to spontaneous succession, part was planted by trees and part was restored. Within this thesis the structure of vegetation and peat properties were investigated in the areas with different vegetation and management in Borkovická blata. The success of restoration was evaluated using these parameters.
Vliv kořenových exudátů na dekompozici rozpuštěné organické hmoty v rašeliništi
ŽAMPACH, Ondřej
The aim of this thesis was to assess the effect of root exudates on the biodegradability of dissolved organic matter. The experiment was done in laboratory conditions, using the dissolved organic matter sampled in a spruce swamp forest located in Šumava National Park and an artificial mixture of root exudates prepared according to known composition of root exudates released by peatland plants. Main hypothesis was that the input of root exudates into the peatland pore water will affect decomposition of less-degradable dissolved organic matter, with the resulting effect dependent on the quantity and quality (C:N ratio) of the input.
Ombrotrophy and minerotrophy of acidic wetlands - ecological and environmental indicators
Hanousková, Andrea ; Neustupa, Jiří (advisor) ; Šťastný, Jan (referee)
In this thesis I focus on different aspects of two basic types of peatlands - ombrotrophic bogs and minerotrophic fens, that differ in the source of their water supplies. In case of the bogs, all the moisture comes from precipitation, the fens are in varying degrees supplied with water from the mineral soil and bedrock. This concept is based on the assumption that hydrological conditions are essential for other properties of acidic wetlands, especially for vegetation, which is still the subject of discussion. Therefore I mention different gradients of peatlands (pH, nutrients and minerals) and important processes (succession, accumulation of peat) with regard to their relation to minerotrophy and ombrotrophy and I discuss their importance for the entire ecosystem. In the second part of my thesis, I focus on the algal assemblages in peatlands, which despite its immense diversity often form a neglected component of these ecosystems. The structure of algal communities vary in space and time under the influence of various factors, including, among others, ombrotrophy and minerotrophy. Powered by TCPDF (www.tcpdf.org)
Carboniferous tropical ecosystems of euramerican province
Frojdová, Jana ; Opluštil, Stanislav (advisor) ; Sakala, Jakub (referee)
This thesis deals with the tropical terrestrial ecosystems of Late Carboniferous (Pennsylvanian) time. It is especially focussed on description of the Carboniferous tropical forest and its components. Introductory parts of the thesis deal with the general characteristics of Carboniferous period, including fauna and flora, distributions of continents and how was the climate of this period. Second part follows the characteristics of particular components of the Carboniferous tropical forest, i.e. of individual plant groups and genera, and their ecological demands. Characterised are plants and their assemblages in tropical lowlands as well as in upland areas, rarely preserved in sedimentary record. In the next part I characterise the dynamics of the forest of Carboniferous tropics and discuss potential mechanisms which controlled the floristic changes including plant extinction. The role of climate changes, which had great influence on vegetation, is discussed as the possible main control. In the separate chapter I describe extinction of arborescent lycopsids. Key words: ecosystem, tropical forest, lowland, climate changes

National Repository of Grey Literature : 45 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.