Academic literature on the topic 'Složení společenstev'

The aim of this study was to use pigments to determine freshwater phytoplankton composition . The samples were collected from freshwater lakes in the Czech Republic and Germany. The pigment analyses were conducted using the High Performance Liquid Chromatography (HPLC). The HPLC data were processed by computer program CHEMTAX to calculate the composition of phytoplankton. The obtained pigment data were compared with standard light microscopy which was used to obtain more detailed taxonomic resolution.

This work focuses on changes in the composition of planktonic communities and water quality in the Pístovice pond. Samples were collected and monitored throughout the year. They were collected at the same locations everytime, mostly at the same time, one month apart. Then Theky were processed subsequently in a chemical laboratory at the Faculty of Agronomy, Institute of Zoology, Fisheries, Hydrobiology and beekeeping. The results show us the composition of planktonic communities (phytoplankton and zooplankton) and their representation and changes during the year. At the same time we can find out the chemical composition of the monitored parameters and their progress and final water quality. These changes are closely related to the change of temperature in the area and subsequently changed one parameter affects the second and the closely related and the composition and representation of individual planktonic communities. The works conclusion is that the chemical parameter values of Pístovice pond water including the composition and representation of planktonic communities fall within the typical values of the chemistry of our stagnant water and ponds.

Ladybugs are often used in biological control, because of their predatory way of life and potential ability to control many insect pests. So far, a number of studies was performed on this family, on their hunting strategies, other life history strategies, population dynamics, dependence of their distribution in time and space on the abundance of prey etc. However, the temporal changes in species composition and relative or absolute abundance of ladybugs were not yet examined along an altitudinal gradient. This is why I have focused my work on these dependencies. I tested the following hypothesis: overwintering sites in Coccinellidae are usually located at lower altitudes, where the individuals eventually attack their prey on the earliest budding trees; as season goes on, ladybugs follow the trends in environmental conditions and food and move to higher located sites; at the end of the season, ladybugs return back to their overwintering sites. In the research area in the Beskydy Mountains, 12 experimental sites were selected, evenly spaced along an elevational gradient of 350-482 m above sea level at each location. During the season, 12 measurements at two-week intervals were performed, each containing 2x300 sweeps. A total of 3064 of ladybug individuals were collected, belonging to 11 species. The...

This thesis describes invertebrate community on cadavers of small mammals, in particulat how cadaver size influences abundace, density, species richness and composition of the necrobiont community. Cadaver size preference of present insects is also described. Field experiments were performed in 2014 in meadow habitats in spring, summer and autumn season. Cadavers were chosen in three weight groups: mice (20 g), small rats (100 g) and large rats (400 - 500 g). Invertebrate abundance increases with cadaver mass, density of the community remains constant. Larger cadavers also have higher species richness. Most dominant ecological guild are necrophages, represented mosty by blow flies (Calliphoridae). Cadaver size preference of recorded insects differ, necrophagous and predatory taxa tend to prefer larger cadavers. Omnivorous carrion beetles (Silphidae: Nicrophorus) prefer small cadavers. Sex of the carrion beetles (Silphidae) does not affect their cadaver size preference, males and females of particular species have very similar preferences. Keywords Ephemeral resource patch, cadaver, necrobiont, size, abundace, diversity, competition, insect communities

The aim of the diploma thesis was a seven month research at the valley waterworks reservoir called Opatovice by Vyškov na Moravě. Taking of the water samples was carried out once a month from two sampling places, which were located on the leeward and windward sides. On the same day these water samples were analyzed at the Fishery and Hydrobiology Department of the Mendel Univerzity in Brno, where there were determined physical and chemical parameters of water, quantitative and qualitative content of the plankton associations. The results were compared with my bachelor thesis: The Development of the Quality of Water in the waterworks reservoir Opatovice, with the results from the previous years, which were provided by the Water Supply and Sewerage company, plc in Vyškov, with the valid legislation of the Czech Republic and with selected waterworks reservoirs situated in the south Moravian region.

The thesis focuses on studying changes of microbial communities living in the soil contaminated by heavy metals. Two sites with different degree of contamination were selected in the Příbram area. Respiration was measured in vitro in the soil samples supplemented with various carbon sources and different concentration of cadmium. The respiration showed that even at cadmium concentration of 1000 mg.kg-1 the community is viable and capable of utilization of substrates while increasing the respiration rate. Enviromental DNA from soil samples was isolated and 16S rRNA gene of actinobacteria was amplified. The terminal restriction fragment length polymorphism analysis showed a clear difference between the profiles of both sites. The shifts in the community profiles were observed also after the addition of substrates. The quantification of total bacteria and actinobacteria was performed by quantitative PCR based on amplification of part of the 16S rRNA gene. The more contaminated site contained slightly more bacteria, but almost twice the actinobacteria than the less contaminated one. The sequencing of amplicons of a part of 16S rRNA gene by Illumina showed an increase in proportion of actinobacteria and changes of their community structure in the more contaminated site. The conclusion was made that, high...

This thesis aims to answer the question whether heterogeneity of agricultural landscapes affects the richness of species, and looks at community composition of butterflies inhabiting 38 insular steppe grassland reserves situated in Southern Moravia, Czech Republic, using quantitative butterfly records and digitised data on landscape composition within the reserves and in surrounding perimeters.

Mechanisms maintaining species diversity in managed meadows are not still well understood. To assess the effect of several important factors on species composition of meadow communities, species regeneration abilities were studied in the course of several years. The research was based on manipulative experiments, where species establishment and survival in seed addition experiments as well as during natural regeneration was observed. By comparison of species establishment in intact and disturbed vegetation, effect of dispersal limitation, abiotic conditions and competition was assessed as well as regeneration ability of different functional groups.

Dry grassland are among the most endangered plant communities mainly due to the overgrowth of a number of localities. That is why from the beginning of the 21st century pasture with mixed herds of sheep and goats is restored on the most valuable dry grassland sites in the Bohemian Karst as the way of maintaining these habitats. Concurrently, research sites each 1x1 m in size were set up at four pastured localities, and were paired with control sites equipped with a fence for the research of grazing effect on vegetation. The main aim of this work was to evaluate the effect of grazing on the diversity of bryophytes at the forty pairs of the above-mentioned areas in three types of calcareous dry grasslands. In addition to the inventory of bryophytes, data on the most important abiotic and biotic factors of the environment were recorded on individual sites. The total number of bryophyte species found at the research sites is 46. 37 species were found at the grazing areas and the same number was at the fenced areas. Minimal differences in the number of species of grazed and unspoilt areas were also found in the comparison of individual localities. The grazing effect was shown up more significantly on species richness in the comparison of individual types of communities, especially in broad-leaved dry grassland (T3.4). There was a 40% increase in the number of species on grazing areas. The environmental factors have a positive effect on the species abundance mainly due to the higher slope of the terrain and the correlation with the larger occurrence of the stones, the smaller coverage of the herb layer and the litter. These conditions prevailed in areas with rock outcrop vegetation with Festuca pallens (T3.1), where the largest species richness of bryophytes in area was found. In the obtained data, the influence of grazing on the species composition of bryophytes on grazed and unspoilt areas was also assessed with the statistical methods and the Sörensen test of beta-diversity. The results show that grazing significantly influences the species composition towards open grassland and supports the growth of the bryophytes T3.1 plant community at the expense of the T3.4 plant community