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Extreme abiotic conditions as determinants of phytoplankton structure in high mountain lakes
Mihál, Martin ; Nedbalová, Linda (advisor) ; Hořická, Zuzana (referee)
There are many areas with extreme environmental conditions in the world. One of them are high mountain lakes which are located above treeline. Bachelor thesis presents the main abiotic conditions as determinants of phytoplankton structure in high mountain lakes. It has to cope with significant changes in light conditions and high intensity of sunlight during ice-free periods and with an important diminution of radiation by snow and ice cover. The thesis also discusses the influence of temperature, which is related to the duration of the ice and snow cover and a stratification of lakes. It characterizes local factors, such as topographic shading, morphology of lakes and character of basins, which affect chemical and physical properties of lakes. The thesis also mentions the impact of atmospheric deposition and other factors on nutrient concentrations in the water column. In addition, it discusses the adaptations of phytoplankton to environmental conditions, which include development of deep chlorophyll maximum, biosynthesis of protective compounds and nutrition strategy (mixotrophy). The thesis shows that there are many specific abiotic factors, which influence phytoplankton in high mountain lakes and all these factors interact. This results in a characteristic species composition with prevalence of...
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Seasonal dynamics and vertical distribution of Crustacea in the deep stratified reservoir Josefův Důl (the Jizera Mountains, Czech Republic)
Adámek, Radek ; Hořická, Zuzana (advisor) ; Vrba, Jaroslav (referee)
The zooplankton of Josefův Důl, a large and deep drinking water reservoir recovering from acidification, develop in relation to the improving water chemistry but also predation by salmonid fish re-stocked at the end of the 1990s. Crustacea are represented by small numbers of several species only, and nothing is known about their distribution in the water column. Recently, picocyanobacteria Merismopedia sp. became dominant in the phytoplankton, which hampers substantially the treatability of the raw water. The aim of the thesis is to describe the seasonal dynamics and vertical distribution of Crustacea in the Josefův Důl reservoir, together with parameters of the environment, and to study their possible diurnal vertical migrations in the summer period.
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Historical development of zooplankton of the Starolesnianske lake (the High Tatra Mountains, Slovakia) in the context of global changes
Blechová, Magdalena ; Hořická, Zuzana (advisor) ; Sacherová, Veronika (referee)
The aims of the thesis were to document the history of the Cladocera (Crustacea) community structure in the Starolesnianske Lake (the High Tatra Mountains, Slovakia) with regards to environmental changes (e. g., Medieval Warm Period, Little Ice Age, anthropogenic acidification, recovery from acidification), and to analyze in detail the development of zooplankton (Cladocera, Copepoda, Rotifera) during the peaking acidification and recovery from acidification (1978 - 2015). Based on results of both the approaches, the appropriateness of using historical data on zooplankton in Tatra lakes between 1909 - 1913 (Minkiewicz, 1914) as a reference condition for the evaluating biological recovery from acidification should have been assessed. The methods used were paleolimnological analyses of lake sediment (namely subfossil Cladocera), analysis of recent zooplankton, and analyses of lake water chemistry. It was found that in the historical record, relative abundances of Cladocera species significantly changed cca 150 years ago (at the end of the Little Ice Age and, in the main, in the period of anthropogenic acidification). The lake, though, has had a very stable species composition of Cladocera during the last cca 2,000 years, represented by four species: Alona quadrangularis, Alonella excisa, Ceriodaphnia...
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Palaeoecological research of mountain lakes in the Carpathian Region: a review
Blechová, Magdalena ; Vondrák, Daniel (advisor) ; Hořická, Zuzana (referee)
The bachelor thesis is a review based on paleoecological research of mountain lakes in the Carpathian mountain region. The aim is to describe lake sediment archives and evaluate current studies and discuss possibilities of future research. This review of the current state of research suggests that there are many challenges and opportunities for future research in the Carpathians. The final part of this thesis is a list of lakes (potential objects of future analysis) with their parameters, including information about paleoecological analysis that have been done. Keywords: Carpathians, Paleoecology, Paleolimnological records, Multi-proxy approach, Mountain lakes.
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Foraging strategies of invertebrate predators in mountain lakes
Hrdličková, Jana ; Sacherová, Veronika (advisor) ; Hořická, Zuzana (referee)
In mountain lakes, which were affected by acidification in the past or in the present, invertebrate species have become top predators and they influence the whole community. This thesis deals with foraging strategies of three of these predators, Cyclops abyssorum and Heterocope saliens (Crustacea: Copepoda) and Glaenocorisa propinqua (Insecta: Heteroptera) in the model localities Černé lake, Plešné lake and Prášilské lake. The main aim was the determination of food composition and food preferences of these predators. The quality and quantity of consumed food I investigated with a microscope using a method which has not been published yet. To make a microscope preparation I used Potassium hydroxide or Lactic acid in order to dissolve soft organic matter, so that the chitinous particles were well visible. The found food of animal origin was subsequently compared with the prey availability with the use of Jacobs' index. In addition to this research, a feeding experiment with G. propinqua was carried out. The food of all the invertebrate predators was dependent on food availability or eventually on the season of the year. G. propinqua mostly preferred as a prey members of Daphniidae family and then the species Polyphemus pediculus (Cladocera), if they were available (Prášilské lake). In Plešné lake,...
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Historical occurrence of bark beetle (Coleoptera: Scolytinae) in the Bohemian Forest, Czech Republic, and possibility of its study in lake sediments
Vytisková, Markéta ; Hořická, Zuzana (advisor) ; Hruška, Jakub (referee)
The bachelor's project is closely related to the problem of bark beetle calamities in the Bohemian Forest National Park in the Czech Republic, and to a possible use of paleolimnological methods for their historical reconstruction. The importance of subfossil beetles as a proxy in assessing past changes in the nature is growing, and the occurrence of remains of Scolytinae in lake sediments has been confirmed - also in the Bohemian Forest paleolake Stará jímka. The thesis is a literature review of (1) the relationship between spruce forests and bark beetle gradations in the area, and (2) chitinous remains of bark beetle and other Scolytinae preserved in lake sediments, and their paleoecological implications. Key words Bohemian Forest (Czech Republic), spruce forests, bark beetle, paleolimnology, subfossil Coleoptera, paleolake Stará jímka
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Structure of zooplankton in reservoirs of the Jizera Mountains during the peaking anthropogenic acidification and recovery from acidification (1992-2011)
Bímová, Tereza ; Hořická, Zuzana (advisor) ; Seďa, Jaromír (referee)
Acidic atmospheric deposition and acidification of soil and water on the Earth's surface, due to emissions of sulfur and nitrogen into the atmosphere, have led to drastic changes in the composition of surface waters and their biota in many regions of the world over the last century. The number of species and biomass of phytoplankton, zooplankton and benthos were reduced, or some components (zooplankton, zoobenthos, fish) became extinct. In the Jizera Mountains (Northern Bohemia, Czech Republic), the man-made acidification has always been combined with a natural acidity (dystrophy) of waters, caused by a high amount of organic acids. Despite a strong recovery of water chemistry from acidification, that has started in the 1990s, biological recovery is delayed and much more complex. This master thesis is a study of the succession of zooplankton (crustaceans) in mountain reservoirs Souš, Bedřichov and Josefův Důl after decades of strong acidification. Biological recovery from acidification has been in progress differently in the drinking water reservoir Souš, which has long been limed, in the Bedřichov reservoir with naturally high content of organic material, and in the drinking water reservoir Josefův Důl, which is the largest and deepest one and which was most affected by acidification. Recovery of...
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