National Repository of Grey Literature 19 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
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.
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...
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.
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,...
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
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...
Phytoplankton of drinking water reservoirs in the Jizera Mountains, Czech Republic, in relation to treatability of water
Čermáková, Anna ; Hořická, Zuzana (advisor) ; Procházková, Lenka (referee)
The area of the Jizera Mountains (northern Bohemia) was significantly affected by acid atmospheric deposition in the second half of the 20th century. This mountain area has a very sensitive geology and is characterized by the predominance of spruce stands, naturally acidic shallow soils of podzolic type, large areas of peat bogs in the upper plateau, a rough climate, and a very high annual rainfall. The frequent heavy rains and a low infiltration capacity of soils brought about floods in the past, very dangerous for the populated foothills. , so in the early 20th century For that reason, a plan was proposed to construct a system of reservoirs for a flood protection of the area. In the 1970s, the need for new sources of drinking water increased in the area. The Souš retention and recreation reservoir was rebuilt to a drinking water reservoir in 1974, and a new drinking water reservoir Josefův Důl was bulit in 1982. Both the water bodies have had a dystrophic character since the beginning, and the Souš reservoir suffers from naturally high concentrations of aluminum. Due to the anthropogenic acidification, the reservoirs were fishless until brook charr (Salvelinus fontinalis) were successfully (re)introduced in the 1990s, and the diversity and numbers of the zooplankton were very low. The...

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