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Diversity and succession of spontaneous vegetation in urban environment
Rejchrtová, Lucie ; Vojta, Jaroslav (advisor) ; Adámek, Martin (referee)
Urban vegetation is important due to its functions (e.g. aesthetic, spiritual, recreational, hygienic). In the city, vegetation and its succession are influenced by factors such as nature in the same or altered form. Compared to the surrounding landscape, the city's climate is warmer, the urban soil has an increased pH, it is drier, it can contain more nutrients, heavy metals and salt. In the city, human activity, and humans themselves are the main plant breeder and biotope disturbant. As a result of all the above, plants with higher demands on heat, light, alkalinity, nutrients and disturbances occur in the city. These are often alien species, which are much more in the city than in the surrounding landscape due to the more frequent occurrence of early successional stages. The proportion of alien species during succession decreases in favor of the native species. The total number of species (even within each group of species - native species, archeophytes and neophytes) is higher than in the surrounding landscape due to the high diversity of biotopes and the introduction (intentional and unintentional) of species by human activity. Keywords: urban vegetation, succession, diversity, anthropogenic factors, alien species
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The crayfish plague pathogen Aphanomyces astaci in its introduced ranges: vectors, introduction pathways, genetic variation and host-pathogen interactions
Mrugała, Agata ; Petrusek, Adam (advisor) ; Füreder, Leopold (referee) ; Vralstad, Trude (referee)
- ABSTRACT - The crayfish plague pathogen, Aphanomyces astaci, is responsible for substantial declines and local extinctions of native European crayfish populations. As a consequence, the pathogen is now listed among 100 world's worst invasive alien species. The spread of A. astaci is greatly facilitated by its natural hosts, North American crayfish, that thanks to a long co-evolutionary history with the crayfish plague pathogen evolved efficient defence mechanisms. In contrast, European, Australian and Asian crayfish species are highly susceptible to this disease agent. However, progress of A. astaci infection in native European crayfish was observed to differ between distinct pathogen strains, indicating variability in their virulence. Indeed, we demonstrated a relationship between patterns in crayfish immune response and A. astaci virulence in an experimental infection involving the European noble crayfish and three differently virulent crayfish plague strains. The European continent is currently inhabited by at least eight North American crayfish species. The carrier status was confirmed in six of them, including also Orconectes cf. virilis occurring in the Netherlands and the UK. In this country, we detected Aphanomyces astaci presence in some populations of the non-indigenous crayfish species as well...
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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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Risks arising from breeding and introduction of aquarium snails
Jarošová, Martina ; Vrabec, Vladimír (advisor) ; Jan, Jan (referee)
Information was gathered regarding all aquarium and already introduced alien snail species (Gastropods), which are being imported to Europe. For the integrity of the research non-native and aquarium clams (Bivalve) were also included. Profiles of species were created based on collected information and the data were subsequently used for creating questionnaires. Questionnaires of each species were processed by FI - ISK, version 1.19 screening tool. Score of invasiveness risk potential was evaluated for each species individually. Surveyed taxa were divided into three groups according to their scores: low risk, medium risk and high risk. Celetaia persculpta was evaluated as aquarium snail (Gastropods) with the lowest risk for native fauna of Czech Republic. According to the results, Pomacea maculata and Pomacea canaliculata are the aquarium snails (Gastropods) with the highest invasiveness risk potential. The riskiest introduced species is Potamopyrgus antipodarum. Scabies crispata and Hyriopsis bialata are clams (Bivalve) with the least risk for the native fauna of Czech Republic. Corbicula fluminea and Dreissena polymorpha were analyzed as clams (Bivalve) with the highest invasiveness risk potential. By comparing aquarium species with species that were already introduced into Czech nature, I conclude that the aquarium snails (clams) do not represent similar risk like the alien species that were introduced without the share of aquarists.
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Dynamika šíření invazních druhů rostlin v ČR za různých scénářů globální klimatické změny
DAPHNE ČR - Institut aplikované ekologie, České Budějovice ; Jihočeská univerzita v Českých Budějovicích, Přírodovědecká fakulta, České Budějovice ; Hrázský, Záboj ; Mihulka, Stanislav
Projekt si dal za cíl zhodnotit predikční systémy a vybrat vhodné pro podmínky ČR, vytvořit variantní mapy potenciálního rozšíření invazních druhů pro jednotlivé scénáře globální klimatické změny, vytvořit mapy míst zájmu (místa ohrožení biodiversity, místa vhodná pro monitoring, místa vhodná pro včasný zásah do průběhu invaze), zhodnotit možné ekonomické zatížení vlivem šíření nepůvodních druhů a formulovat návrh strategie managementu rostlinných invazí.
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