|
|
Biodiversity of chironomid fauna in mountain lakes and streams influenced by acidification and recovery from acidification.
Černocká, Veronika ; Stuchlík, Evžen (advisor) ; Frouz, Jan (referee)
This thesis examines the influence of acidification on the largest group of macroinvertebrates in mountain lakes and running waters - chironomids. The diversity of chironomids has been associated with temperature, the concentration of dissolved oxygen in the water, the amount of nutrients, and also with the ability to survive in conditions (e.g. extreme pH) that are not suitable for other taxa. Because of this the family Chironomidae has become a dominant group of macrozoobentos in many assemblages affected by acidification. The Bohemian Forest lakes and the Tatra Mountain lakes belong to the most frequently studied locations, which were affected by acidification. The peak of acidification was in the 1980s. It turned out that, during the acidification, the number of chironomids changed and also the species composition of their assemblages. The main reason was a change of trophic status, which chironomids reflected more than a change of pH. A decrease in the number of species occurred after the pH dropped below 5. Until then, only their relative abundance had been affected. Chironomids are also influenced by the toxic effect of Al. The most important factor affecting chironomids fauna is not the value of pH, but the change of food supply. Acid stream food webs are often viewed as being...
|
|
|
Influence of fish pond management, land use in catchment and climate change on species composition of blue-green algae blooms
Kroupová, Kristýna ; Stuchlík, Evžen (advisor) ; Pivokonský, Martin (referee)
The aim of the thesis was to explain expansion of cyanobacterial blooms and the change of their species composition in surface standing waters during the last 2-3 decades as a result of fishery management, land use in catchments, and climate change. Cyanobacteria possess a range of unique and highly-adaptable eco-physiological traits, which enable them a mass occurrence and a dominance over the other phytoplankton groups under recent anthropogenic changes (nutrient loading and rising temperatures). Moreover, many species of cyanobacteria produce cyanotoxins, which increase their resistence against zooplankton grazing and cause severe deterioration of the water quality. In consequence of changes in fishery management (a decrease in the use of superphosphate as a fertilizer during the year 1970), the fish stock density increased and the clear water phase disappeared. This is responsible for a change in species composition of cyanobacterial water blooms. Summer blooms of Aphanizomenon flos-aquae were replaced with A. flos-aquae var. klebahnii. The current composition of water blooms in ponds differs considerably from the typical composition in the 1990s. For example, recent expansion of Woronichiniana naegeliana is caused by the higher stock densities and the shift from a two-year cycle of fishery management...
|
|
|
Hydrology of mountain seepage lakes
Kohn, Tomáš ; Stuchlík, Evžen (advisor) ; Šobr, Miroslav (referee)
The aim of this thesis is a review of the hydrological balance of mountain lakes, focusing on lakes without ground outflow, or with a huge share of seepage upon the outflow. This thesis deals, step by step, with the methods of collecting data for each input and output to the hydrological system. It is also concerned with the possibilities of monitoring ground water movement and rainfall-runoff models.
|
|
|
Freshwater macroinvertebrates and their use for assessment of environmental changes in running waters
Kolaříková, Kateřina ; Stuchlík, Evžen (advisor) ; Matěna, Josef (referee) ; Porcal, Petr (referee)
The dissertation thesis consists of five articles, bringing together results from investigations of macroinvertebrates in running waters. The use of freshwater macroinvertebrate organisms to assess environmental changes was based on the following facts: a) the presence/absence of taxa provide information about abiotic factors and/or about the pollution status of the site, b) they are indigenous and sedentary species, so that the environmental implications can be related to the site they live on, c) the organisms accumulate xenobiotic elements or compounds, thus reflecting the contaminant level in the environment. Localization of the sampling sites was related to the "hot-spots" of environmental problems. The particular investigations were carried out in the Elbe River catchment and in the Czech mountains on the selected headwater streams of the GEOMON network of the Czech Geological Survey. The Elbe was considered one of the most polluted rivers across Europe in the second half of the past century until the socio-economic transformation after 1989. The headwater streams in the Czech Republic were chosen with respect to the problem of acidification. The ability of bioaccumulation of xenobiotics in macroinvertebrate organisms was used to assess the long-term load of the Elbe ecosystem with trace...
|
|
|
Diurnal vertical migrations of zooplankton in a stratified mountain reservoir
Adámek, Radek ; Hořická, Zuzana (advisor) ; Stuchlík, Evžen (referee)
The thesis - a literature review - was aimed at the phenomenon of diurnal vertical migration (DVM) of zooplankton, in relation to particular conditions in the Josefův Důl reservoir in the Jizera Mountains (northern Bohemia, Czech Republic). The area of the Jizera Mts has a very sensitive geology, and thus suffered a strong anthropogenic acidification in the second half of the 20th century. The consequence was a long-term degradation of chemistry and biology of soils and surface waters. The waters in the upper plateau of the mountains were fishless, with a low diversity and biomass of both the phytoplankton and zooplankton. Recovery from acidification is slowest in the deepest reservoir, Josefův Důl. Due to its morphology, thermal stratification, newly re-stocked brook charr population, and invertebrate predators' occurrence, the zooplankton distribution in the vertical profile is expected to be irregular, with DVM. The following diploma project, oriented to seasonal changes and vertical distribution of the zooplankton in the Josefův Důl reservoir, should contribute to long-term data on biological recovery of the reservoirs from acidification, and explain the role of biotic parameters in zooplankton succession.
|
|
|
Influence of climate force forest management on hydrological regime of headwater streams
Pícha, Zdeněk ; Stuchlík, Evžen (advisor) ; Křeček, Josef (referee)
Hydrological functions of catchment area are an important part of the ecosystem. There are three approaches that deal with the issue of catchment hydrological functions. These three approaches are summarized in the work, there are shown the advantages, disadvantages and results of some studies. Hydrological functions of catchment area, especially the runoff process, significantly affect forests growing in the catchment, especially their species composition, age and type of soil. The paper summarizes insights about how that tree species, especially beech (Fagus sylvatica) and Norway spruce (Picea abies) affects runoff, water infiltration into the soil and interception. The next section is then summary the influence of forests on floods, which is not so large as is generally expected. At the end of the work is an overview of some studies dealing with the hydrological balance and runoff processes were carried out in the headwaters of the river Litavka and outline possible further research in this area. Key words: runoff, catchment, forest, infiltration, hydrological modelling, pair catchments
|
|
|
Fotogrammetric analyses of aerial pictures of mountain landscape and generation of DEM
Hynštová, Marie ; Stuchlík, Evžen (advisor) ; Matějíček, Luboš (referee)
This thesis describes the stereo photogrammetric method used for digitalization of terrain elevation data of choosen area and the applications of digital elevation model (DEM). The main part of the thesis consists of DEM generation methodology, including stereo photogrammetric evaluation of aerial pictures, quality control of evaluating process, DEM creation and revision. DEM was created in software Edras Imagine 8.6. The thesis results in detailed description of DEM creation in the high mountain terrain selected in the High Tatra Mountains. Grid DEM of cell size 1x1 meter is attached. Key words: mountain lakes and catchments, photogrammetry, aerial pictures, DEM
|
|
| |
|
| |
|
| |
guest ::
RSS feed.