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Detailed taxonomic and clonal structure of the Daphnia longispina species complex on the longitudinal gradient of the Želivka Reservoir
Stodola, Jakub ; Petrusek, Adam (advisor) ; Vaníčková, Ivana (referee)
Canyon shaped reservoirs are characteristic by specific environmental horizontal gradients, so they enable existence of several species of the Daphnia longispina complex in one water body. Due to preference of distinct environmental conditions Daphnia species occurre in the different localities. The aim of my thesis was to analyze detail taxonomical and clonal structure of Daphnia longispina group by ten microsatellite markers on longitudinal gradient and compare it between two consecutive seasons. Simultaneously I received newly discovered divergent mitochondrial lineage from Želivka reservoir. It was confirmed, that the distribution of species and their hybrids in water reservoir was non-concidental and the taxonomic spatial distribution is in two consecutive seasons relatively constant. On the contrary the spatial and temporal distribution of clones was very heterogeneous. Clonal diversity in the interspecific hybrids was lower than in the coexisting parental species. This finding supports the hypothesis, that there exist reproductive barriers between parental genomes. Most of the clones were substantively variable, but several clones that occurred in both seasons in similar localities were found. It is possible that some clones are able of overwintering in hypolimnion and in the spring...
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Microparasites and fecundity of Daphnia at environmental gradients of canyon-shaped reservoirs
Hubová, Jana ; Petrusek, Adam (advisor) ; Macháček, Jiří (referee)
The original aim of my diploma thesis was examination of fixed samples of cladocerans from the Daphnia longispina species complex from reservoirs Vír and Vranov for the presence of 4 groups of microparasites: microsporidia, oomycetes, the protozoan Caullerya mesnili, and the yeast Metschnikowia bicuspidata. The next aim was to determine the effect of parasites on Daphnia fecundity, and determination of their spatial and temporal distribution within reservoirs. From the total number 4452 of examined Daphnia females, however, only 56 individuals were infected. This number was not sufficient for the planned analyses. As I recorded for all examined individuals the clutch size, I thus dealt to a large extent with an alternative issue: the temporal and spatial variation of, and the influence of environmental factors on Daphnia fecundity. Both studied reservoirs are characteristic by canyon-shaped profile that allows formation of environmental gradients on the horizontal as well as vertical axis. The results confirm that reservoir identity, season, and location within the reservoir (or gradient of food supply) have all significant effects on fecundity. During my work I have encountered difficulties associated with determining microparazites from fixed zooplankton samples. The appendix section of my thesis...
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The importance of woodlots and their ecological characteristics for birds in an intensively managed agricultural landscape
Rajmonová, Lenka ; Reif, Jiří (advisor) ; Šálek, Martin (referee)
Various types of woody vegetation are a key biodiversity refugee in intensively managed agricultural landscapes. However, the role of woodlots, representing an important type of such a vegetation, remains overlooked so far. Whereas the previous studies focused on the effect of their area, shape and isolation, consequences of variation in their habitat quality for biodiversity were not assessed up to now. This thesis is thus one of the first studies focusing on woodlots as a specific habitat for birds in agricultural landscape. My goals were: (I) to find out what is the bird community composition of woodlots in a Czech landscape, (II) to find out, what are the key habitat predictors of bird species richness and abundance in woodlots, (III) to describe differences in habitat preferences among various guilds and (IV) to formulate recommendations for conservational practice. I surveyed birds in 82 woodlots in an intensively managed landscape in Central Bohemia, Czechia, and measured variables describing woodlots' habitat quality together with woodlots' area, shape, isolation and types of surrounding land-use. I recorded numerous forest and non-forest bird species (57 in total), including some endangered farmland birds. The habitat variables showing significant relationships to bird community...
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Phytolith spectra of the recent vegetation in north-east Africa: testing the potential of phytolith analysis for palaeoecology
Kuncová, Kristýna ; Pokorná, Adéla (advisor) ; Jamrichová, Eva (referee)
Phytoliths are mostly formed by groundwater silica carried upwards in a plant's vascular system and consequently accumulated in different parts of the plant. After the plant's death, the phytoliths shaped in specific morphotypes are released into the soil. Phytolith assemblages found in the soil can therefore provide information on the previous vegetation cover. The use of phytoliths as a paleoecological tool is based on their high stability in a broad spectrum of environments, even in arid conditions which are usually not suitable for preservation of pollen grains and plant macro-remains. Analysis of surface phytolith assemblages linked to the parallel study of modern vegetation is offering a good opportunity to refine our knowledge of paleoecosystems of NE Africa by evaluating the interpretation value of the fossil data. Modern phytolith assemblages are usually interpreted by using their phytolith ratio to estimate the density of tree cover, the aridity, and the proportion of C3 and C4 grasses (Barboni et al. 1999). Here we show a comparison of soil phytolith assemblages on a 400 km long climatic gradient reaching from semidesert to short grass savanna. And we also show local variability in phytolith assamblages at one of localities in comparision with grass reference collection. This master...
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Environmental determinants of bird species richness and population densities in sub-Saharan Africa
Dubský, Marek ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
The research of factors influencing bird's species diversity and abundance will allow us to manage the landscape in the way to create suitable conditions for survival of species. For the purposes of this work, I divided bird assemblages into 3 groups on local level: forest birds, shrubland birds and grassland birds. The forest bird species were most influenced by height of canopy, its compactness and fragmentation of the forests. The size of the fragment, fragment matrix, isolation of the fragment and birds sensitivity to edge effect were deciding factors of number of species and individuals in each fragment. The shrubland birds were most influenced by vegetation structure in meaning of presence of shrubs, trees and grassland. They were also influenced by vegetation species composition, frequency and form of disturbances (fire, grazing), they reacted positively to transformation of landscape into agroecosystems and they reacted negatively to shrub encroachement. Grassland birds reacted to various height of grass, they reacted negatively to presence of trees and shrubs and also to disturbances caused by human. It is the least studied group of birds in Africa. As fot the elevation gradient, the lowland assemblages of birds changed to mountains assemblages at attitude of about 1250 above the sea...
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Microparasites and fecundity of Daphnia at environmental gradients of canyon-shaped reservoirs
Hubová, Jana ; Petrusek, Adam (advisor) ; Macháček, Jiří (referee)
The original aim of my diploma thesis was examination of fixed samples of cladocerans from the Daphnia longispina species complex from reservoirs Vír and Vranov for the presence of 4 groups of microparasites: microsporidia, oomycetes, the protozoan Caullerya mesnili, and the yeast Metschnikowia bicuspidata. The next aim was to determine the effect of parasites on Daphnia fecundity, and determination of their spatial and temporal distribution within reservoirs. From the total number 4452 of examined Daphnia females, however, only 56 individuals were infected. This number was not sufficient for the planned analyses. As I recorded for all examined individuals the clutch size, I thus dealt to a large extent with an alternative issue: the temporal and spatial variation of, and the influence of environmental factors on Daphnia fecundity. Both studied reservoirs are characteristic by canyon-shaped profile that allows formation of environmental gradients on the horizontal as well as vertical axis. The results confirm that reservoir identity, season, and location within the reservoir (or gradient of food supply) have all significant effects on fecundity. During my work I have encountered difficulties associated with determining microparazites from fixed zooplankton samples. The appendix section of my thesis...
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Detailed taxonomic and clonal structure of the Daphnia longispina species complex on the longitudinal gradient of the Želivka Reservoir
Stodola, Jakub ; Petrusek, Adam (advisor) ; Vaníčková, Ivana (referee)
Canyon shaped reservoirs are characteristic by specific environmental horizontal gradients, so they enable existence of several species of the Daphnia longispina complex in one water body. Due to preference of distinct environmental conditions Daphnia species occurre in the different localities. The aim of my thesis was to analyze detail taxonomical and clonal structure of Daphnia longispina group by ten microsatellite markers on longitudinal gradient and compare it between two consecutive seasons. Simultaneously I received newly discovered divergent mitochondrial lineage from Želivka reservoir. It was confirmed, that the distribution of species and their hybrids in water reservoir was non-concidental and the taxonomic spatial distribution is in two consecutive seasons relatively constant. On the contrary the spatial and temporal distribution of clones was very heterogeneous. Clonal diversity in the interspecific hybrids was lower than in the coexisting parental species. This finding supports the hypothesis, that there exist reproductive barriers between parental genomes. Most of the clones were substantively variable, but several clones that occurred in both seasons in similar localities were found. It is possible that some clones are able of overwintering in hypolimnion and in the spring...
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