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Habitat colonization by neophyte Impatiens glandulifera and estimate of factors limiting its spread
Marková, Zuzana ; Hejda, Martin (advisor) ; Malíková, Lenka (referee)
Invasive spread of neophyte Impatiens glandulifera in central Europe started approximatelly eighty years ago. First records of dense cover stands come from belt stands in riparian habitats. The scale of invaded habitats and degree of the dominance of I. glandulifera is more diversified nowadays. This thesis is objected on the dominance and fertility of I. glandulifera within different habitat types and scale of invaded habitats in different parts of invaded range within Europe (i. e. in Czech Republic and Switzerland). The results show that the height and cover (substitutes for biomass and dominance) of this neophyte (i) correlates with the character of invaded vegetation (ii) relates to the degree of hemeroby (a measure of human impact) negativelly, and (iii), of course, both the growth and dominance are positively affected by nutrient content. Fertility does not differ among the types of invaded habitats, but goes up with the height of I. glandulifera and decreases with its cover. Invaded habitats comprises ruderal and riparian vegetation, but also wet maedows, forest clearances, beach and slope forests or weed vegetation.
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Communitiy level impacts of alien invasive plants and the role of native range habitats in plant invasions
Hejda, Martin ; Pyšek, Petr (advisor) ; Duchoslav, Miloš (referee) ; Tichý, Lubomír (referee)
Conclusions Categorization of the species studied according to their impact on invaded communities This study focused on neophytes, species introduced after 1500 A.D., because their impact on native vegetation is higher and more obvious than that of archaeophytes, introduced before that date, due to considerable invasion dynamics and relatively short residence time (Pyšek et al. 2002). The target neophytes, included in the study, differ strongly in their community level impacts. Impatiens glandulifera had a miniscule impact on species diversity and composition, both in the removal experiment and comparative study (Chapter I). This small impact is likely to be associated with this annual species' lower competitive strength, which has a modest root system and forms stands that are not homogeneous in terms of cover. The density of I. glandulifera populations is known to decrease during the vegetation season, as plants fall due the weight of climbers, which are common in invaded riparian communities (Calystegia sepium, Cuscuta europaea - see Beerling & Perrins 1993). Moreover, the character of communities in which I. glandulifera invades, mostly riparian nitrophilous vegetation, does not provide opportunities for competitively weak species even if they are not invaded. This vegetation is dominated by tall,...
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Relationship between species diversity, temperature and productivity for native and non-native plant species
Szostoková, Kateřina ; Šímová, Irena (advisor) ; Hejda, Martin (referee)
Latitudinal gradient of diversity is typically being explained by the three main hypotheses: The Resources Limitation Hypothesis, The Speciation Rate Hypothesis and The Niche Conservatism Hypothesis. In my study I tested basic assumptions of these hypotheses using native and non-native vascular plants obtained from the new database GloNAF (Global Naturalized Alien Flora). I tested an effect of precipitation, NPP, temperature and historical velocity (difference in temperature and precipitation between the Last Glacial Maximum and present) on species richness. Given that the distribution of non-native species is among continents irregular (we can divide them into two groups - Australia with Europe and North America and South America with Africa and Asia), I tested the abovementioned relationships at both - global and continental scale. Species richness of native species increased with NPP, precipitation and temperature and decreased with the difference in temperature. The global distribution of non-native plants increased with precipitation and temperature velocity and decreases with temperature and precipitation velocity, although the results varied for particular continents. Unlike other studies the number of non-native species didn't correlate with the number of native plant species. Concurrently...
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Habitat colonization by neophyte Impatiens glandulifera and estimate of factors limiting its spread
Marková, Zuzana ; Hejda, Martin (advisor) ; Malíková, Lenka (referee)
Invasive spread of neophyte Impatiens glandulifera in central Europe started approximatelly eighty years ago. First records of dense cover stands come from belt stands in riparian habitats. The scale of invaded habitats and degree of the dominance of I. glandulifera is more diversified nowadays. This thesis is objected on the dominance and fertility of I. glandulifera within different habitat types and scale of invaded habitats in different parts of invaded range within Europe (i. e. in Czech Republic and Switzerland). The results show that the height and cover (substitutes for biomass and dominance) of this neophyte (i) correlates with the character of invaded vegetation (ii) relates to the degree of hemeroby (a measure of human impact) negativelly, and (iii), of course, both the growth and dominance are positively affected by nutrient content. Fertility does not differ among the types of invaded habitats, but goes up with the height of I. glandulifera and decreases with its cover. Invaded habitats comprises ruderal and riparian vegetation, but also wet maedows, forest clearances, beach and slope forests or weed vegetation.
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Comparison of ecological requierements of the epiphytic species within Orthotrichaceae family
Franková, Hana ; Plášek, Vítězslav (advisor) ; Hejda, Martin (referee) ; Marková, Ivana (referee)
The thesis is a part of an ongoing research on taxonomy, ecology, and the distribution of epiphytic bryophytes particularly within the Orthotrichaceae family, based on collected bryofloristic records. The database now contains 6500 records. I have analysed interspecific differences in habitat preferences between species, namely their associations with particular phorophytes, pH of phorophyte bark, altitude, and the position on the phorophyte. Individual species differed in their occurrence according to altitude, phorophyte, and pH, though altitude was the most important factor. All analysed species have been shown to represent obligate epiphytes. Some species reveal a tendency to occur preferrentially on northern or western side of the phorophyte, but this tendency is not by any means universal. I discuss these findings in the context of the knowledge of species autecology and current changes in their distribution.
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Habitat colonization by the neophyte Impatiens glandulifera and factors limiting its distribution
Marková, Zuzana ; Hejda, Martin (advisor) ; Frouz, Jan (referee)
Habitat colonization by the neophyte Impatiens glandulifera and factors limiting its distribution The invasive alien Impatiens glandulifera has been present in the flora of The Czech Republic for more then one hundred years. It has colonized banks of all larger rivers and its spread is still in progress. The presence of Impatiens glandulifera is mostly reported from associations with nitrophilous dominant species, mainly riparian tall herb and scrub communities.. However, the impact on native vegetation is rather low in these types of invaded habitats. It cannot be distinguished unequivocally, if this alien's preference for riparian habitats is associated with the site conditions or with the specific dynamics of the river, which i) transports the seeds efficiently and ii) creates sites suitable for the invasion of I. glandulifera via its flooding regime. The spectrum of habitats further from the river that have been reproted to be occupied by this invasive alien seems to be wide (rocks, forest edges and coppice, embankments, wet meadows). Plants tend to be smaller on these sites and generally do not create such dense stands as in riparian habitats, however, they do flower and produce seeds. That is crucial for their futher spread. Studies suggest that if I. glandulifera changes its site and habitat...
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New trends in marketing
Bartoň, Jaroslav ; Skokanová, Dagmar (advisor) ; Hejda, Martin (referee)
This thesis deals with influence and possibilities of using social networks in marketing and using relatively new phenomenon of "group buying" or "Tuangou" for marketing purposes. In the theoretical part the thesis deals with the description of these marketing channels and outlines possibilities of their practical application. The practical part of the thesis examines particular consumers, who are targets of these campaigns and their perceptions of marketing campaigns through mentioned channels. The research among consumers is done by an analysis of secondary data and by collection and analysis of primary data through questionnaires and interviews.
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