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Factors affecting dragonfly species composition in newly created pools and assessment of invertebrate predation on pools zooplankton
Dobiáš, Jakub ; Černý, Martin (advisor) ; Harabiš, Filip (referee)
To identify and quantify the influence of physico-chemical, biotic and geographic factors on the population of dragonflies (Odonata) is an essential tool for research of their ecology. The aim of this study was to 1) assess how these factors influence species richness, diversity and spatial distribution of dragonflies in 42 newly constructed or renewed pools located in the Kokořínsko Protected Landscape Area, which is characterized by two valleys of Liběchovka and Pšovka creeks, low human impact, and a great diversity of small water bodies and 2) use laboratory experiments in order to estimate the relationship between large predatory invertebrates of these pools (Aeshna cyanea, Coenagrion puella, Chaoborus crystallinus and Notonecta glauca) and their common prey (Daphnia curvirostris) in an artificial environment with or without aquatic macrophytes. The pools were monitored and sampled between years 2005 and 2006. In total, 23 dragonflies species were found inhabiting these lentic habitats, comprising 11 species belonging to the suborder Zygoptera and 12 species belonging to the suborder Anisoptera, including a rare species Sympetrum depressiusculum (larvae). Most variability in the dragonfly species richness was explained by the size of the water surface area, followed by the location of the pools (inside...
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Population and spatial dynamics of Winter Damselflies (Odonata: Lestidae)
Jablonická, Zuzana ; Harabiš, Filip (advisor) ; Kadlec, Tomáš (referee)
The main subject of this study was Sympecma fusca, damselfly species representing life history with many specific adaptations. One of the unique adaptation is overwintering in adult life stage outside the water habitat. The aim of this thesis is to analyze distribution of this species in terrestrial environment, as well as changes in abundance during the season. Sympecma fusca is common winter damselfly in Czech Republic, occurring on variety of still freshwater habitats with rich vegetation. During overwintering this species actively searching for micro-habitats situated in terrestrial environment, providing shelter and reducing the mortality risks. Capture-Mark-Recapture Method was applied to describe the population dynamics of this species. The experimental part was divided into two periods: pre-reproductive (autumn) and reproductive (spring). Subsequent analysis provide estimation of total number of individuals in population during season. The results showed significant habitat preference of ecotones between forest and meadow over forest and open habitats. However, this preference was confirmed only during pre-reproductive period, the time when imagoes were looking for suitable shelter for the overwintering. These findings can be used to in understand the habitat preference of this species, but also general factors that can affect its abundance.
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Biotic and abiotic factors affecting territorial and reproductive behaviour of dragonflies (Odonata)
KYBICOVÁ, Tereza
Habitat selection, territorial behaviour and reproductive behaviour of dragonflies (Odonata) are discussed and biotic and abiotic factors affecting their territorial and reproductive behaviour are reviewed. The most important biotic factors are predation risk affecting larval survival and the presence of aquatic vegetation, which provides spatial structure. The review is complemented by a field study of territorial and reproductive behavior of dragonflies at an experimental site, at which the quality of individual pools was manipulated by a combination of the presence or absence of artificial vegetation and the presence or absence of an introduced top predator (late-instar larvae of Anax and Aeshna).
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How predation risk affects the growth and development of dragonfly larvae?
PEROUTKA, Miroslav
Predation and prey responses to predators in aquatic environment are reviewed with emphasis on non-lethal effect of predators on prey life history, antipredator behavior and related mechanisms. The review focuses on dragonfly larvae and other groups of prey with complex life histories, mainly anurans. The review is complemented by laboratory experiments examining the effects of varied food availability and predation risk on a selected species of dragonfly, Sympetrum vulgatum.
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How important are cannibalism and intraguild predation for aquatic insect communities?
PEROUTKA, Miroslav
Cannibalism and intraguild predation in the communities of aquatic insects are reviewed. Special attention is paid to the relationship of predator and prey size and to the impact of cannibalism and intraguild predation on population dynamics and individual life histories. Detection of prey and predator and antipredator strategies are also reviewed. The review is complemented by laboratory experiments on selected species of dragonflies.
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Species variability of bentic organisms in Dračice river classicifed by PERLA system
KOUTNIK, Dalibor
Examination ecological size selected part of river (from village Františkov to border with Austria) on the basis of field watching. Observed results are analysed by system PERLA. Method is based on analysing biodiversity makrozoobenthos sample from fordables running water. Sampling can be apply in running water, where water column not exceed 1 m and speed of water stream to 1 m/s. Taking is made by normal or low water stage.
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