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Dynamical pollination models
Smyčka, Jan ; Herben, Tomáš (advisor) ; Těšitel, Jakub (referee)
Dynamical pollination models (abstract) Pollination is a complex biological phenomenon which may include many interacting plant and animal species. In such a case, and especially when we are interested in effects of spatial structure, it can be helpful to use some formal approach of study, as is dynamical modelling. This thesis describes common methods for pollination modelling in space. The pollination can be divided into two consequent processes - pollinator movement and pollen carryover. Simple method of pollination movement modelling is using some random particle movement patterns, e.g. Brownian motion. This approach is useful mostly for systems with one plant species, or at large scales. More accurate, but difficult, posibility is modelling pollinators" movement through some decision making process based on their behaviour. Pollen carryover models are the necessary "translation" of pollinator movement to variables important for plants. A part of this work is also an analysis of certain pollination models. Their assumptions, predictions and modifications for not yet tackled problems are discussed.
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Populační biologie rostlin napadených systémovými parazity
Koubek, Tomáš ; Herben, Tomáš (advisor) ; Šmilauer, Petr (referee) ; Wennström, Anders (referee)
Three separate studies of the effect of plant pathogen on population biology of its host are presented in the thesis. Two are using field data about a widespread system of plant Falcaria vulgaris and its systemic rust fungus Puccinia sii-falcariae. The first study shows, that the disease prevalences in 40 populations of the plant were correlated with the moisture, the soil reaction and the cover of the herb layer at the localities. This was probably a result of the interaction of the life history of the plant and different effect the disease has at various localities. Similar pattern was found in the second study that aimed to determine long-term effect of the disease at the population level at four chosen localities over 4-5 years. Population growth rates were only rarely predicted to be higher for the healthy part of the population when compared with the whole population. Other analyses have however found big differences among years and localities. The locality type (slope vs. field populations) was important factor influencing population stage composition and importance of life cycle transitions for the growth of the population. Finally, the last study explores the possibility that systemic infection in clonal plants might be able to select against clonality. The result of the modelling showed that more...
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