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Epizoochorous dispersal of vascular plants by large mammals
Mádrová, Terezie ; Lepková, Barbora (advisor) ; Vlasta, Tomáš (referee)
Epizoochorous dispersal is together with endozoochorous dispersal one of the two basic principles of zoochory - the seed dispersion by animals. Epizoochory is defined as the spread of seeds by attachment to the surface of animals, for example in the fur of mammals, feathers of birds, even on the surface of the human clothing if we consider human as dispersal vector. There are plant species, which adapted to the epizoochory during the evolution. We can observe their morphological adaptation such as hooks, various appendages or mucilage. However, the efficiency of these adaptations, also depends on the type of the carrier, which can be either a mammal (for example ungulates or carnivores), bird or a reptile. Epizoochory also has an impact on the biodiversity - it is a mechanism that can spread the seeds across long distances and therefore provide the species variability in the environment. Today it is also an efficient way of dispersion in the fragmented landscape, where the plants are dispersed together with the animals between the fragments of vegetation. Rewilding, which is a method of returning the keystone species into the landscape and therefore restoring the interrupted natural processes, is also related to changes in the landscape. Keywords: epizoochory, seed dispersal, large herbivores,...
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Comparison of three trials used for assassement of ability to disperse by wind and its importance for colonazition of abandoned fields in Asteraceae species
Vlasta, Tomáš ; Knappová, Jana (advisor) ; Kotilínek, Milan (referee)
Several methods are used for studying seed dispersal (seed traps, tracking individual seeds, tracking seeds coloured by fluorescent colours, etc.) However, only a few studies compared results obtained by several methods. In first part of this master thesis, I compared the three above mentioned methods used for studying seed dispersal using species from Asteraceae family. From previous research within the study area (Úštěcko), it is known that dry grassland species are able to colonize abandoned fields. Using seed dispersal data obtained within this theses, I tried to assess the role of seed dispersal on distribution of dry grassland species on abandoned fields both on local and regional scale. The results showed that dispersal curves obtained by the three methods differ significantly. This results may be due to different wind conditions during the experiments. Seed trap data show results from long-term seed dispersal influenced by highly variable wind conditions. In contrary, seed release experiments showed results based on single dispersal event under limited wind conditions. Tracking seeds coloured by fluorescent colours was shown to be not convenient for small seeds, but I can recommend this method for larger seeds. Influence of seed dispersal ability on abundance of dry grassland species on...
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Methods for studying seed dispersal and its importance for colonization of new sites
Vlasta, Tomáš ; Knappová, Jana (advisor) ; Hemrová, Lucie (referee)
Study of seed dispersal is crucial for understanding of several processes in life of plants and landscape. Seed dispesal is very important for persistence of local populations in fragmented landscape, it plays an important role in succession, it helps to protect plant populations againts loss of genetic variability. We usually recognize several types of seed dispersal depending on vector (dispersal by wind, animals and water.) In nature, it is very common that seed can be independently dispersed by several vectors. Therefore, studying of polychory and secondary dispersal is necessery. Methods of studying of seed dispersal are very variable, including seed traps, releasing and following individual seeds, genetics marcers etc. If we study seed dispersal, we should select the most suitable method depending on the aim of the study. We should also take into acount advantages and disadvantages of single method.
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