National Repository of Grey Literature 26 records found  beginprevious17 - 26  jump to record: Search took 0.01 seconds. 
Local dispersal of Golden-ringed dragonfly Cordulegaster boltonii
Hančíková, Barbora ; Černý, Martin (advisor) ; Dolný, Aleš (referee)
We carried out a pilot study of local dispersion and patterns of movement of Golden- ringed dragonfly Cordulegaster boltonii (Odonata: Cordulegasteridae). Cordulegasteridae is a family with many primitive traits present and rather restricted geographical distribution ranges (at least among European species). Their migration seems to be limited despite the body size that predetermines them to high mobility over large spatial scale. Linear habitat (upper parts of narrow forest streams) specialisation along with behavioural ecology (peculiar premating habit of scanning streams for females) is a unique life history, which bring lot of questions. We collected mark-release-recapture data during two adult flight seasons in year 2010 and 2011. We were simultaneously capturing patrolling males along three separate streams (Dračice, Koštěnický and Struha) in total length of 9.9 km in, located in the Natural park Česká Kanada, in the Southern Czech Republic. We captured and marked 440 individuals and recorded 113 recapture events (26 % recapture rate) in year 2010 and 355 individuals were marked, 171 recapture events made (48 % recapture rate) in 2011. Our data suggested high level of stream fidelity (only 10 inter stream dispersal events, 2.8 % dispersal rate). What was as well reflected in a closeness of...
Disperzní a letová aktivita pakomárů stojatých vod (Diptera: Chironomidae)
VEBROVÁ, Lucie
I first review the significance of dispersal for individuals and populations including the role of the most significant environmental drivers on separate phases of dispersal. Emphasis is put on aquatic insects inhabiting small standing waters. The following manuscript summarizes a quantitative study of diel and seasonal flight patterns of adult Chironomidae in the Cep II sandpit in southern Bohemia. It provides one of the first comprehensive treatments of the effect of weather conditions and seasonality on the flight activity of adult Chironomidae, phenology of most common species and differences between terrestrial and aquatic species.
Migrations of dragonflies and damselflies (Odonata)
Hančíková, Barbora ; Černý, Martin (advisor) ; Waldhauser, Martin (referee)
This study is aimed at the phenomenon of migration, which is not still fully explored and which, by different circumstances, undergo several species of dragonflies (Odonata). Only for a few species from several tens of migrants generally, their migration route and strategies are explored. These case studies are described and I am also dealing with those species of dragonflies for which migration is not fully explored, and I am pointing out the other possible fields of research. One of the aims of my work is the comparison of different attributes and strategies of migration in dragonflies with other migrants from insect as well as the migratory birds.
Impact of river system structure on the genetic diversity of reed populations
Fuxová, Gabriela ; Fér, Tomáš (advisor) ; Kubátová, Barbora (referee)
Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...
Landscape structure, habitat properties, species traits or chance: What determines distribution of grassland plants in abandoned fields?
Knappová, Jana ; Münzbergová, Zuzana (advisor) ; Hájek, Michal (referee) ; De Bello, Francesco (referee)
Semi-natural grasslands are among the most threatened habitats in Europe, endangered mainly by cessation of former management practices and conversion into other types of land use. Extensive research has been carried out in European grasslands in last decades, to explain origins of diversity and to provide guidelines for its conservation. However, the very slow response of perennial plants to landscape changes often impedes to accurately evaluate why species occur just where they occur and not elsewhere. Abandoned fields are perceived as potential habitats for species from declining grasslands. Indeed, many species are able to spontaneously colonise abandoned fields, but many other species are absent from communities that develop there. An important question remains what limits their successful establishment. By answering this question, we can gain also important insights into factors determining species distribution in grasslands because colonization of recently abandoned fields by grassland species is the ongoing process which is not obscured by historical changes in landscape structure. The very basic aim of this thesis was to evaluate the status quo of dry grassland plants in fields abandoned in last two decades. And in the second step, to identify what are the main constrains of successful...
Breeding site fidelity in waterfowl
Kejzlarová, Tereza ; Musil, Petr (advisor) ; Fuchs, Roman (referee)
The thesis is concerned in breeding site fidelity and focused on Anseriformes, especially Anatidae. Higher fidelity ratio in females than in males is an interesting pattern of breeding site fidelity in this bird group. On the contrary, an opposite pattern, i. e. higher fidelity ratio in males prevailed among other bird species. This study is aimed at describing this phenomenon and discussion of factors affecting fidelity ratio. Among, the most important factors, the importance of the previous breeding success and environmental conditions is underlined. The study includes data about fidelity ratio from 40 studies of breeding site fidelity in Anatidae.
Dispersion of freshwater gastropods
Buďová, Jana ; Černý, Martin (advisor) ; Juřičková, Lucie (referee)
Freshwater gastropods (Mollusca: Gastropoda) belong to two tradional taxonomic groups: prosobranchs (Prosobranchia) and pulmonates (Pulmonata). Most of these molluscs are characterized by low vagility. Therefore they usually rely on passive dispersal. Their dispersal vectors are mostly birds and water. Animals can transport snails both externally and internally. Direct methods (capture.mark.recapture, radio - tracking) and genetic methods could be used to study dispersal. For genetic studies can be used many type of molecular markers, but the recently most popular are microsatellites. According to recent studies, the dispersal of freshwater gastropods is probably not as frequent and wide - spread as assumed before. Key words: freshwater snails, dispersal, dispersal vectors, capture - mark - recapture, molecular markers, population genetics
Zooplankton community development in newly created small pools
Vondrák, Daniel ; Černý, Martin (advisor) ; Devetter, Miloslav (referee)
The relative importance of local and regional factors to community build-up is a core issue in contemporary ecology. Studies based on research of newly created aquatic habitats may improve understanding of these processes. We monitored zooplankton colonization rates and community assemblage in 20 newly dug and isolated temporary pools in Kokořínsko Protected Landscape Area. The region is characterised by deep stream valleys, extensive land use, low human influence, low waterfowl migration activity and practically absence of large water bodies. After the first hyproperiod all temporary pools were rebuilt to a permanent form. In contrast to expectations, in both cases we observed immediate colonization of newly created habitats by two main groups of zooplankton (crustaceans and rotifers), but only rotifers (Rotifera) were capable of fast successful establishment of viable populations. Cladocerans (Crustacea: Cladocera) and copepods (Crustacea: Copepoda) were observed rarely and usually in low abundances (< 1 ind-l ). 10 months after the filling of permanent pools one ostracod species (Crustacea: Ostracoda), Notodromas monacha, was recorded as well. During the 8 months of temporary pools existence the presence of 1 cladoceran and 1 cyclopoid copepod species and 12 rotifer taxa was recorded, icluding...
Dispersal and flight activity of aquatic insects: mechanisms and consequences for community assembly.
VEBROVÁ, Lucie
Water insects represent the considerable part of the freshwater communities. One of the most spectacular ability of those organisms is dispersion among various localities. The understanding of the dispersion mechanisms is of the key importance for unhiding the basic ecological and evolutionary processes such as colonization or maintaining high diversity patches. The aim of this thesis is to summarize findings about the dispersion and its main drivers. The experimental part deals with the influence of environmental factors on the flying activity of the water insects.
Ants as dispersers of seeds in meadow vegetation
KONEČNÁ, Marie
Seed dispersal by ants was investigated in a wet meadow. Vegetation and viable seed bank of places with and without ant-hill were compared. The response of ants to the presence of elaiosom on seeds of myrmecochorous plant Pedicularis sylvatica was observed.

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