National Repository of Grey Literature 52 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Development of selected invasive species and meadow vegetation classification algorithm in the Krkonoše Mountains using hyperspectral data
Jelének, Jan ; Kupková, Lucie (advisor) ; Halabuk, Andrej (referee)
Development of selected invasive species and meadow vegetation classification algorithm in the Krkonoše Mountains using hyperspectral data Abstract The thesis deals with utilization of airbone APEX hyperspectral image data for selected invasive species and meadow vegetation classification in the study area of the Krkonoše Mountains National Park. The mian goal of the thesis was to develop of classification algorithm based on proposed vegetation indices. The approach was based on the utilization of in-situ LAI, fAPAR, chlorophyll content data and analysis of their relation with vegetation spectral properties. The work also deals with several problems regarding LAI - vegetation indices relationship, namely saturation of LAI and mutual correlation of LAI and chlorophyll content. Tha classification was focued on invasive species Rumex alpinus and Lupinus polyphyllus, meadow vegetation with dominant Nardus stricta and dominant Trisetum flavescens and cutted lawns. Besides the proposed approach, the presented work resulted in several classification maps of study area and in spectral libraries, containing ground level spectra of studied invasive species, meadow vegetation types and several other meadow species. Keywords: hyperspectral image data, APEX, LAI, fAPAR, vegetation indices, invasive species, meadow...
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...
Factors associated with invasiveness in the genus Impatiens: interaction of species traits, competition and environment
Čuda, Jan ; Pyšek, Petr (advisor) ; Kollmann, Johannes (referee) ; Prach, Karel (referee)
The aim of this thesis was to identify factors that contribute to invasiveness of species in the genus Impatiens. This genus is horticulturally attractive and includes several species that are known to have naturalized outside their native ranges, while others did not escape, in spite of being frequently cultivated. When looking for traits associated with invasiveness, it is useful to focus on congeneric species. Their traits and dispersal modes are less influenced by phylogeny, than when comparing unrelated species or even complete floras. This helps to account for traits that favour invasive species over native ones and thus identify potential invaders more precisely. A superior invader performance is attributed to a competitive advantage over native species that can lead in extreme case to competitive exclusion of the latter. Invasive and native species com- pete only if their niches overlap and the strength of competition depends on niche similarity. Importantly, invasive species are considered to be able to maintain their high competitiveness over a wide range of environmental conditions, while native ones often have narrower environ- mental optima. Lastly, competitive outcome can vary over life stages and depends on the degree of species dominance, which is rarely taken into account. Spread and...
Invasive water invertebrates in Czech Republic
Kolářová, Lucie ; Tátosová, Jolana (advisor) ; Dočkalová, Kateřina (referee)
An introduction of invasive species is considered to be one of the most actual problems of these days and is also related with water environment and water invertebrates. Occurences of many non-native species has been recorded in waters of the Czech Republic and these species can be divided into two groups. Species of the first group are invasive alien species - their ecological patterns (e.g. high growing rates, high reproductive capacity or ability to transfer exotic diseases) make their spreading more successful. North-American crayfish species (Orconectes limosus and Pacifastacus leniusculus), Dreissena polymorpha or Dikerogammarus villosus are the typical representatives of this group. The spreading of these species is very remarkable, since their introduction causes many harmful effects and has negative impacts on native fauna. However, the appearance of other group of water invertebrates has been found in our waters. These are also non-indigenous species, but their spreading is very inconspicuous - they do not reach high population densities and their invasion does not cause negative impacts on native fauna and ecosystems. The evidence of these harmless invasive species has been recorded thanks to the monitoring programs and we possibly wouldn't know about them without this monitoring. The...
Epiphytic lichens of the Czech Republic
Pelechová, Kateřina ; Svoboda, David (advisor) ; Peksa, Ondřej (referee)
This bachelor thesis researches the works of the years 1908-2013, which deal with the occurrence of epiphytic, i.e. growing on tree species, lichens in the Czech Republic. In the introduction there is briefly interpreted definition of lichens and epiphytes and the relationship between lichens and heir environment (with an emphasis on air pollution) is described. The main part is devoted to the processing of data found in the literature - when and on which tree species is the lichen growing - and is divided into two periods (1908-1970 and 1971-2013). The frequency of lichen species changes between periods - links between lichens and tree species and preference of the species and its changes over time, changes in preference of pH of bark of trees and tree species with the highest number of species of lichens. The study contains a list of 429 lichen species occurring on tree species in the Czech Republic. Powered by TCPDF (www.tcpdf.org)
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.
Watermilfoils (Myriophyllum) in the central Europe
Hrdinová, Magdalena ; Trávníček, Pavel (advisor) ; Prančl, Jan (referee)
Genus Myriophyllum L. (watermilfoil) belongs to one of the most species-rich genera within Haloragaceae (Saxifragales). It includes three invasive species, which are of major concern - European M. spicatum L., North American M. heterophyllum MICHX. and South American M. aquaticum (VELL.) VERDC. All of them occur in Central Europe as well as native M. verticillatum L. and M. alterniflorum DC. lacking more significant invasive growth up to now. It is not only its invasivness that makes genus Myriophyllum so fascinating. It also displays extremely high phenotypic plasticity which is accompanied by determination difficulties. Moreover, recent research indicates that Myriophyllum tends to hybridize producing more invasive hybrids than parental taxa. Such traits pose a formidable challenge to scientists to deal with possible future invasive growth of non-indigenous Myriophyllum species in Central Europe. Therefore, thorough study of factors influencing evolution success of plants should be conducted. One of the key factors seems to be polyploidy. Research into polyploidy offers a new approach to watermilfoil issues. Additionally, according to preparatory study all native Central European Myriophyllum species can be easily distinguished by flow cytometry. That enables to study polyploidy in an...
Impact of polyploidy on the invasive potential of Vicia cracca
Líblová, Zuzana ; Münzbergová, Zuzana (advisor) ; Mihulka, Stanislav (referee)
This work is about diploids and tetraploids of Vicia cracca species, the two commonly occurring cytotypes. The first part is devoted to the distribution of cytotypes of this species in the secondary range in North America. It was hypothesised that polyploid species become invasive more frequently than diploid species. Their greater success may be given by greater variability of genes obtained by polyploidisation and gene subfunkcionalizing. All invasive populations of Vicia cracca species involved in this study were tetraploid. Based on this we can say that only tetraploids are invasive in this secondary colonized area. Polyploid species can be better competitors thanks to their expected better growth characteristics and stress resistance. Therefore the second part of this work is testing the hypothesis that polyploids are more variable in size of different parts of the plant body and therefore more able to grow even in conditions that are not suitable for diploids. As predicted by the EICA hypothesis (evolution of increased competitive ability), secondary colonized area also provide more space for further evolution and we can expect that growth characteristics of plants from the invasive range will differ from plants of the same ploidy from the original distribution range. This part of the work...
Legal regulation of alien species of plants and animals
Tisovská, Pavla ; Stejskal, Vojtěch (advisor) ; Damohorský, Milan (referee)
Legal regulation of alien species of plants and animals Abstract This thesis deals with the legal regulation of invasive non-native species of plants and animals, i.e., preventing their spread and minimizing the negative consequences that these species cause on individual ecosystems and biodiversity in general. The aim of this work is to analyse the related effective international, EU and Czech national legislation and to define the most significant changes concerning the relevant Czech laws in connection with the implementation of Regulation (EU) No. 1143/2014 and Regulation (EC) No. 708/2007. At the beginning, the work deals with the history of the spread of non-native species, as identifying the critical pathways of their spread is also an important knowledge necessary for creating effective legislation and also the definition of fundamental terms - non-native species, invasive non-native species, and biodiversity. Furthermore, the work deals with the most important international treaties in this area, i.e., the Convention on Biological Diversity, the Convention on the Conservation of Migratory Species of Wild Animals, the Convention on the Conservation of European Fauna and Flora and Habitats and the Madrid Protocol to the Antarctic Treaty, with the relevant European Union legislation, i.e., a network...
Management of native and alien plants in garden monuments
Sádlo, Jiří ; Pergl, Jan ; Pejchal, Miloš ; Perglová, Irena ; Petřík, Petr ; Štefl, Lukáš ; Vojík, Martin
The work covers garden monuments in context of spontaneous nature and the occurrence of non-native plant species. We present the management approaches for selected groups of invasive species. The text was written in the context of fields other than monument care and ecology and nature conservatioin. We offer not a simplified methodological guide with a prepared solution of standard situations. We prefer to formulate the text at a greater distance and show the problems themselves, we offer a way to think about them. The approaches are accompanied with examples. In the text, we show local solutions using case studies.
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