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Habitat requirements and competition between native and invasive Impatiens species
Čuda, Jan ; Skálová, Hana (advisor) ; Prach, Karel (referee)
Three of Impatiens species are widespread in the Czech republic, one is native, two of them invasive. Because all species occur in relatively similar habitats, the question is, whether the invasive species can negatively affect the native species, or even the original can can be displaced. The aim of the thesis was: (i) to compare habitat requirments of the Impatiens species, (ii) to determine if the coexistence of species is possible, (iii) to assess the impact of invasive species to the original species. The investigation was carried out using two sets of permanent plots in 5 localities. In the first set with a total of 84 plots (combinations of occurrence of the three species) site characteristics as tree cover, soil humidity, slope and bare land cover were directly measured and nutrient, light, humidity and soil reaction characteristic assessed using Ellenberg indicator values. The second set contained a total of 45 plots with one of the native-invasive congener pair being removed and the intact controls. Number, cover and height of the plants were assesed. The key enviromental factors determining distribution of the species were soil moisture for I. noli-tangere and I. parviflora, and tree cover for I. glandulifera and I. parviflora. Ellenberg indicator values had poor explanation value;...
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Effect of metapopulation structure and environmental factors on population biology of Impatiens noli-tangere infected by powdery mildew Podosphaera balsaminae
Chalupníková, Jana ; Koubek, Tomáš (advisor) ; Čuda, Jan (referee)
Studies performed on natural pathosystems revealed that the spatial structure of the metapopulation plays an important role in the development and spread of disease; phytopathological experimental studies have also revealed a significant effect of climatic factors on the presence of the disease (incidence) and the level of infection (prevalence) in populations. The aim of this study was to explore a natural pathosystem from both sides at the same time and to see which local and spatial environmental factors influence the development of pathosystem. Study focuses on population biology of natural pathosystem Podospaera balsaminae - Impatiens noli-tangere, which has not been investigated yet. In the study area (between the city Sázava (Benešov district) and village Vlkančice) host populations occurred in 78 (64 of them were infected) in 2013 and 82 populations (61 of them were infected) in 2014. Size of host populations had the strongest effect to incidence and prevalence of disease in the pathosystem. In larger populations, the disease occurred more often, developed faster and was higher. The rate of spread of the pathogen territory and the rate of population host connectivity had also strong effect. The abundance of pathogen in the studied area and the level of connectivity of host populations also...
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Habitat requirements and competition between native and invasive Impatiens species
Čuda, Jan ; Skálová, Hana (advisor) ; Prach, Karel (referee)
Three of Impatiens species are widespread in the Czech republic, one is native, two of them invasive. Because all species occur in relatively similar habitats, the question is, whether the invasive species can negatively affect the native species, or even the original can can be displaced. The aim of the thesis was: (i) to compare habitat requirments of the Impatiens species, (ii) to determine if the coexistence of species is possible, (iii) to assess the impact of invasive species to the original species. The investigation was carried out using two sets of permanent plots in 5 localities. In the first set with a total of 84 plots (combinations of occurrence of the three species) site characteristics as tree cover, soil humidity, slope and bare land cover were directly measured and nutrient, light, humidity and soil reaction characteristic assessed using Ellenberg indicator values. The second set contained a total of 45 plots with one of the native-invasive congener pair being removed and the intact controls. Number, cover and height of the plants were assesed. The key enviromental factors determining distribution of the species were soil moisture for I. noli-tangere and I. parviflora, and tree cover for I. glandulifera and I. parviflora. Ellenberg indicator values had poor explanation value;...
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