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Population biology of Dianthus carthusianorum in populations infested by anther-smut
Kasner, Marek ; Koubek, Tomáš (advisor) ; Dostálek, Tomáš (referee)
Anther-smuts (Microbotryum violaceum s. l.) are systemic plant pathogens sterilizing their hosts, thus decreasing its reproduction on the expense of own sporulation. The spores are, consequently, transmitted by pollinator vectors and deposited on healthy flowers. This thesis contributes novel, to date missing information about population-level impact of the pathogen that severely influences its host fitness by examining a relatively new model species Dianthus carthusianorum. Additionally, it considers the effect of pre-dispersal seed predators (caterpillars of Hadena moths). Deterministic matrix models were used for the quantification of the effects of both plant antagonists. Notably, the use of such type of models is rather unique in population biology of plant pathogens. The research was conducted in three localities in Střední Povltaví area in years 2018-2021 when the demographic data were collected, reflecting the whole plant life cycle. During the annual censuses we gathered not only the information about the vital rates of the plants (growth, reproduction, infections...) but also selected size characteristics of permanently marked plants were measured to explore possible changes induced by a systemic infection. The seed recruitment and seedling growth data were provided by seed-addition...
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The influences of biotic interactions on population biology of Sanguisorba officinalis
Větvičková, Anna ; Janovský, Zdeněk (advisor) ; Jičínská, Jana (referee)
Plants can interact with many different organisms on many trophic levels in their life. In this thesis I investigated how three biotic inertactions, powdery mildew infection, caused by Podosphaera ferruginea, predispersal seed predation by Dusky Large Blue (Phengaris nausithous) and Scarce Large Blue (P. teleius) and deer grazing affect life cycle and population biology of the Great Burnet (Sanguisorba officinalis L.). I also analysed their preferences of environmental conditions. Most of studied plant populations growth rates (λ) were lower than 1 and population decreased, but quite surprisingly for more populations vegetative reproduction was more important than reproduction by seeds. All intraction mentioned above affects more generative reproduction, and thus their influence on Great Burnet population dynamics is low, even with modelled maximal possible effect. Environment conditions analysis showed that powdery mildew occurs on sites with more flowering individuals, where spreading is very easy, butterflies preferred high, well noticeable flower heads grown high above other vegetation and host ant presence. For host ants' presence model locality was only significant variable.
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Population dynamics of cushion plant Silene acaulis in the High Tatras
Krchová, Emma ; Münzbergová, Zuzana (advisor) ; Macek, Martin (referee)
This diploma thesis is studying population dynamics of endangered species Silene acaulis in the High Tatra Mountains in Slovakia. Silene acaulis is a species of extreme alpine habitats creating cushions that provide a microclimate acting as a facilitator of establishment of other species in the alpine communities. This dome-like structure has one woody taproot making it easier to distinguish each individual. It is thus a perfect model species for determining the population dynamics drivers. The findings help in understanding future behaviour of the species and whole alpine ecosystems. Population data have been collected since 2013 or 2014 in two valleys in the High Tatras providing a database suitable to study various effects on species performance. Data collection includes marking, measuring, counting of flowers and capsules, viability and new seedlings recording, gender identification and comparison of vegetation structure within and in close proximity of a cushion. The data on vegetation were analysed using CCA ordination and the population data were analysed using Integral Projection Models. The results show that the breeding system of Slovak S. acaulis is gynodioecious and the gender affects the size of cushions, individuals with both female and hermaphrodite flowers being the biggest. The...
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Population models of plant life-cycles and their modifications by diseases and herbivores
Kasner, Marek ; Koubek, Tomáš (advisor) ; Koupilová, Klára (referee)
Pathogens and herbivores are two important groups of organisms with predominantly negative impact on their plant hosts. Although relationships at the individual level are relatively well understood, the data acquired by those studies cannot be easily translated into effects on the population. Various types of population models, also used in the case of the interactions, give us valuable insight into population dynamics. This bachelor thesis at first describes mechanisms and effects of plant pathogens (with emphasis on pathosystems with anther smut Microbotryum violaceum) and herbivores at the individual and population level for the demonstration of diversity of the systems and to stress the discrepancy between the two hierarchical levels. Furthermore, matrix and integral projection models are introduced as invaluable tools for population dynamics projections and understanding the underlying results of the interactions on plant populations. These models use the entire plant life cycle and require long-term censuses of demographic data. The role of these models in plant-pathogen interactions seems heavily underappreciated, however, and thus there is only a small number of studies with their application. The thesis describes mechanisms of the models, modifications in specific life-cycles and their...
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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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Dynamics of rare and threatened species on local and regional scale- from theory to practice
Lampei Bucharová, Anna ; Münzbergová, Zuzana (advisor) ; Tichý, Lubomír (referee) ; Jiménez, Ares (referee)
To assess the status of a rare plant species, we must first understand the factors that affect the size of populations and their numbers. In this thesis, I study processes affecting plant species prosperity on local scale (paper 1), factors influencing species distribution in landscape and ability of species to colonize new habitats (paper 2) and species traits responsible for gene flow between established populations (paper 3). Since I work with rare plants, I also aim to turn theoretical knowledge into practical recommendations for nature conservation (paper 4) to help effectively preserve rare and endangered species. In the first 3 papers, I work with two rare fern species restricted to serpentine rocks, Asplenium adulterinum and A. cuneifolium, in a study system covering 10 × 10 km. I found that both species are long living (several decades) and in the study region, populations are in a good state and slowly growing. Even very small populations (10 individuals) have quite high chance to survive. In both fern species, I found dispersal limitation, which might be surprising regarding huge production of small spores in ferns (paper 2). The species differ in ploidy and thus, also mating system. A. adulterinum is tetraploid and its main breeding system is intragametophytic selfing. A. cuneifolium is...
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Ecology and genetic diversity of Gentiana pannonica populations in different geographical and habitat scales
EKRTOVÁ, Ester
The thesis focused to population ecology and genetics of subalpine species Gentiana pannonica. Pollination ecology of species and generative reproduction in different habitat (primary vs. secondary) were investigated in the field. Genetic variation and structure of G. pannonica populations were studied in three disjunct parts of its distribution range: the Eastern Alps, the Bohemian Forest, and the Giant Mts. Present distribution of G. pannonica in the central past of the Bohemian Forest were processed.
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Population biology of \kur{Rhytidoponera} ants (Hymenoptera:Formicidae)
BIZOS, Jiří
Ants from the genus Rhytidoponera are known for specific type of social organization in which some workers can reproduce. Species of this ants are commonly occuring in lowland rainforests of New Guinea but their biology is unknown to great extent. This thesis reviews available molecular methods suitable for study of population structure and phylogeography of Rhytidpoponera ants in rainforest environment.
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