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Species and cytotype diversity of invasive Symphyotrichum species in Central Europe
Varvažovská, Adéla ; Slovák, Marek (advisor) ; Hodálová, Iva (referee)
The cytotypic variability of Aster species of the genus Symphyotrichum is relatively well-explored within the territory of North America, where this species originates. Unfortunately, in Europe, where Asters were originally introduced as ornamental plants, they have received limited attention in terms of their overall as well as cytotypic variability. The number of publications and data concerning cytotypic variability and karyology in Europe is very limited, with some reporting the occurrence of several species and higher ploidy level species complexes. Asters naturalize in many places, capable of reproducing both vegetatively and generatively, and primarily colonize habitats disturbed by human activities. As a result, they have been classified as invasive plant species. From a biosystematic perspective, Asters constitute a highly complex group due to their high morphological and karyological variability. This situation is further complicated by the phenomenon of polyploidy and intense interspecific and intraspecific hybridization. These factors contribute to the challenging task of identifying individuals and populations and assigning them to specific taxa. The aim of this thesis was to clarify the cytotypic variability of wild-growing Aster species of the genus Symphyotrichum (Asteraceae) in the...
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Invasive species mapping beyond activities of Nature Conservation Agency
Joščáková, Aneta ; Pergl, Jan (advisor) ; Chobot, Karel (referee)
Invasive species are a persistent problem in environmental protection. In order to grasp invasions properly and especially for their effective management, it is necessary to have good information on the occurrence of invasive species. However, mapping activities to date have mostly been narrowly focused, mainly on sites of conservation interest and selected flagship species. Records from these activities are now concentrated in the Nature Conservancy Central Register of the Nature Conservation Agency of the Czech Republic. This database is currently the best data source on the occurrence of invasive species in the Czech Republic. Nevertheless, it still does not contain a satisfactory number of records. The largest gaps are in areas outside the interest of nature conservation. Mapping of these areas can be done through citizen science, which is specifically very suitable for mapping invasive species. Another promising but rarely used source of data on the occurrence of invasive species is the grey literature, the potential of which has been explored in this bachelor's thesis. Thesis and professional surveys organised by the county were examined. It was shown that all the studied works and surveys contained large amount of good data on the occurrence of invasive species. Unfortunately, these data...
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Proti americkému brouku! Lze odstranit raka signálního z malého toku?
JAKŠ, Jiří
Biological invasion by invasive alien crayfish species is a serious problem for the whole ecosystem. Non-native crayfish species have significantly better biological equipment and ability to adapt to the environment in which they live. This makes them very dangerous animals not only for our native crayfish species. One of these dangerous alien species is the signal crayfish (Pacifastacus leniusculus - Dana, 1852). This species was imported from North America because of economic reasons. At the time of introduction of this non-native species, such massive spreading was not expected as well as negative impacts on native species. Now it is necessary to reduce the number of crayfish and thus significantly help the whole ecosystem. There are several ways how to reduce the population of signal crayfish and other non-native crayfish species. It was the subject of this work and it was only necessary to choose the appropriate method. Finally, one of the least invasive methods was chosen for this work, which is catching crayfish by hand and the net. The Křesánovský brook near Vimperk was chosen as a locality, where is located the dense population of the signal crayfish. This species already significantly reduced all the typical fish species that normally lived in this trout brook, and also significantly reduced the number of native crayfish (Astacus astacus - Linnaeus, 1758). This species can be seen there only rarely and often of a poor fitness. At the beginning of presented work, the main question was how successful this catch method would be. According to current theoretical knowledge, the method of catching crayfish by hand with net has a low success rate and it is not possible to remove the crayfish completely from the stream using this method. However, no one has conducted such a study at small accessible stream and it was therefore appropriate to carry out such a study. After intensive catches in the period from April to November, it was found that we are not able to remove or significantly reduce the number of crayfish living in this stream. However, there are several alternatives that can be used. These alternatives can be found in this work.
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Uplatnění nepůvodních dřevin na narušených stanovištích: vliv stanovištních a krajinných faktorů
PROŠKOVÁ, Miloslava
The effect of local and landscape factors on establishment of alien woody species in various post-industrial sites in the Czech Republic was evaluated. The first part of the thesis was focused on the establishment and survival of late successional and alien woody seedling in differently restored sites (spontaneous succession vs forestry reclamation), each with various successional stages (young, middle, late), This part continued in the topic of Bc. Thesis to detect changes in a period up to three years since the establishment of the experiment. The second part, dealt with the invasive potential of selected alien woody species Quercus rubra, was studied in three abandoned post-mining sites represented by sand pits and compared with the species establishment in undisturbed afforested sites dominated by Pinus sylvestris. These two parts were conducted in Třeboňsko Protected Landscape Area. The last part evaluated the effect of local site and landscape factors at a broad national scale. For this purpose, the phytosociological relevés from Database of Successional Seres (DaSS) were used.
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The role of sexual reproduction in the invasive behavior of polyploid species complexes in alien plants
Jarůšková, Dominika ; Slovák, Marek (advisor) ; Urfus, Tomáš (referee)
Alien plants have a significantly negative impact on the composition and structure of resident communities. They might cause a remarkable decrease in their biodiversity and even severely threaten the existce of rare species. One of the factors that can accelerate invasive behaviour of alien species is whole-genome duplication (polyploidy), which can, via increased genetic diversity, improve overall fitness, reproduction abilities and competitiveness of polyploid cytotypes compared to their diploid counterparts. This work represents a literature review focused on the reproductive mechanisms of invasive species and the role they play in their invasive behavior. Reproduction is further analyzed in the context of polyploidy, with a special focus on the effects of polyploidy on sexual reproduction. Last but not least, the work presents and discusses case studies that deal with selected invasive polyploid species complexes and analyze the success of their sexual reproduction in their native as well as invaded distribution range. Key words: alien species, polyploidy, sexual reproduction
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American mink (Neovison vison) - biology of an invasive species.
Hlaváčová, Petra ; Vohralík, Vladimír (advisor) ; Anděra, Miloš (referee)
The American mink is considered to be an invasive, alien species across Europe, North Asia and also in South America and now it is perceived as a permanently growing treat for native biodiversity. Mink is an extremely adaptable predator, which achieves to adapt to almost any conditions and different food niches. The aim of this study was to contribute to cognition of biology of this species in Czechomoravian highlands condition. A telemetry study was run between 2004 and 2012 during which in total six individuals (3 males and 3 females) were being monitored on the Sázava River near Havlíčkův Brod. This study was supplemented by usage of photo traps. A couple of finding can be drawn from this study. Mainly, the records show the significant differences between sexes. Males and females differ in home range size, in day/night activity and in length of day movements. The second part of this study was focused on distinguishing tracks of three different species of mustelids: American mink, European mink and Western polecat. In total, 211 tracks obtained from these three species were measured. Seven points on a track has been identified, and the computer program Measuring tracks automatically created 131 parameters. These parameters were processed with canonical discriminant analysis. The results showed...
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Analysis of ichtyofauna of the Czech Republic focused on alien species
Goldstein, David ; Hanel, Lubomír (advisor) ; Andreska, Jan (referee)
This thesis analyzes the ichthyofauna in Czech Republic in historical terms, i.e. how was the data on the occurrence of native species of fishes and lampreys collected. Particular attention is given to species alien to this territory - the following species are elaborated in more detail: Carassius auratus, Ameiurus nebulosus, Pseudorasbora parva, Ctenopharyngodon idella, Hypophthalmichthys molitrix, Aristichthys nobilis, Gasterosteus aculeatus, Coregonus maraena,Coregonus peled, Acipeneser baerii, Acipeneser stellatus, Acipenser gueldenstaedtii. The history of the introductions, the current situation in the Czech Republic and the impact on native ichthyofauna are listed (a more detailed evaluation of invasiveness is included for Carassius auratus, Pseudorasbora parva). Finally, the efforts to enrich the local ichthyofauna by introducing new species are generally evaluated.
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Methodological tool for assessment of authenticity of woody taxa in garden monuments
Pejchal, Miloš ; Štefl, Lukáš
The aims of the publication are to enable activities in the field of determination of the taxonomic authenticity of woody species. We provide an approach suitable to cases when there is not enough data on the history of their use, both from archival materials and from the evaluation of woody vegetation elements preserved in the given monument, the results of garden archaeology, etc. The data covered by the publication contribute to the determination of both aspects of authenticity and for the evaluation of the authenticity of the material substance of woody vegetation structural elements. We also provide information on the time of introduction into culture.
Plný tet:  PDF
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The cytotype diversity and population demography of invasive aster from Symphyotrichum lanceolatum a S. novi-belgii groups in Central Europe.
Varvažovská, Adéla ; Slovák, Marek (advisor) ; Chrtek, Jindřich (referee)
Asters from Symphyotrichum lanceolatum and S. novi-belgii a species complexes are native to North America from where they were imported to Europe as ornamental plants during the 19th century. They were naturalized and later became invasive in the humid habitats along rivers and lakes. Both species groups are karyologically and morphologically highly variable what is reflected in their complex taxonomy. A crucial role in the formation of their intricated diversity play inter- and intraspecies hybridization, polyploid evolution as well as phenotypic plasticity. The biological and ecological diversity of Asters was thoroughly studied in their natural environment in North America, however only little is known about their variability in their new, invaded European habitats. Numerous polyploid cytotypes were reported from their native distribution range in North America, however, only a single cytogeographic study in Europe has been published to date. The outcomes of this study accompanied by occasional chromosome counts indicated the existence of higher ploidy levels only. Specifically hexaploid and octoploid cytotype was reported for S. lanceolatus while hexaploids in S. novi-belgii. The problem of the karyological variability of these taxa in Europe deserves attention and further research. Key words:...
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