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Changes in pollinator behaviour under different plant spatial aggregation
Štenc, Jakub ; Janovský, Zdeněk (advisor) ; Bartoš, Michael (referee)
Plants often occur aggregated into clusters and this spatial pattern is supposed to affect pollinator behaviour and pollen dispersal. Such pollinator reaction may influence reproductive success of zoogamous plant species both in terms of number of available mates and their genetic diversity (nearby growing plant individuals are also often closely related, especially in clonal plants). In the present thesis, I investigated the influence of plant spatial aggregation on pollinator behaviour and how this translates into pollen transfer. For that purpose, I carried three experiments. In the Experiment 1, I used potted plants placed into arrays and aggregated into four patches in order to track the pollen dispersal by means of a UV-dye pollen analogue. I manipulated distances between plants within clusters (dense × loose) and between clusters (near × far). I conducted this experiment for three plant species differing in their pollinator spectra. In the Experiment 2, I observed pollinator foraging sequences (sequences of visited plant individuals) under the same experimental design as for the first experiment, but I carried out this experiment for five plant species. In addition in one study species, Dianthus carthusianorum, I conducted the Experiment 3 to get better insight into pollination effectiveness...
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Plant-Animal Interactions in an Inselberg Ecosystem: The Effect on Reproduction of Selected Species
Vlasáková, Blanka ; Sklenář, Petr (advisor) ; Porembski, Stefan (referee) ; Jersáková, Jana (referee)
Conclusions This thesis provides detailed insight into plant-animal relationships that are involved in reproduction of inselberg species. The results are interpreted in relation to the ecosystem functioning and they also contribute to the general knowledge on specialization in plant-animal interactions (Chapter 2 and 3), floral resources (Chapter 2, 3, and 5), pollinators' attraction (Chapter 2), relations between diaspore's characteristics and animal dispersal (Chapter 4), and conflicts among plant life stages that follow ovule fertilization (Chapter 4). As Clusia aff. sellowiana dominates the shrub vegetation, the study on its reproduction is the initial step to understanding the dynamics of the shrub patches and potential succession on the inselberg. The nocturnal pollination system of Clusia aff. sellowiana bears unusual characteristics and signs of specialization. Only one pollinator species, a cockroach Amazonina platystylata, was recorded and this species is apparently sensitive to olfactory attraction cues emitted by the flowers. This is the first evidence of pollination system that involves cockroaches as pollinators and is to some degree specialized. Clusia aff. sellowiana is dispersed by small birds. Because its diasporas are consumed by birds and there is a time lag before they are deposited,...
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Pollination in urban ecosystems
Krygielová, Anna ; Janovský, Zdeněk (advisor) ; Mikát, Michael (referee)
Pollination success in the urban area mainly depends on the characteristics of plant populations and their pollinators, which are determined by the structure and characteristics of the urban ecosystem. Urbanization is a complex and uneven integration of landscape attributes such as habitat fragmentation, a high proportion of built-up area, the often limited size of green areas, and lower connectivity between them. These particular predictors have different effects on plant and pollinator abundance and species diversity. In general, an increasing level of urbanisation reduces the quantity and quality of pollination and therefore negatively affects the reproductive success of plants. On the other hand, in comparison with intensive agricultural landscapes urban areas (especially urban fringes and semi-natural urban areas) can contribute to the diversity, abundance, and reproductive success of plants and the diversity and abundance of their pollinators. This potentially positive influence of the city on biodiversity can be further developed through effective urban planning and appropriate management of existing public and private green areas in the city. Keywords: pollination, urban ecosystems, urbanisation, urban characteristics, urban green spaces, plant-pollinator interactions, plant reproductive success
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Evolutionary significance of visual traits of flowers and their influence on the pollinator constancy
Haveldová, Alice ; Štenc, Jakub (advisor) ; Klečka, Jan (referee)
Flower constancy is a behavior in which the pollinator visits flowers of the same plant species in a sequence more than would correspond to its preference for the given plant. This behavior is advantageous for plants because it can ensure efficient intraspecific pollen transfer which has a positive effect on their biological fitness. More efficient pollen transfer can lead to the selection of (visual and olfactory) flower traits that encourage flower constancy of pollinators. The main visual floral traits that affect constancy include colour, pattern, shape and size. However, these traits are of different importance for pollinators when they are deciding which flower to visit, and therefore their effect on flower constancy varies. The degree of flower constancy also differs between the functional groups of pollinators. Flower constancy is generally low in vertebrates, but insects and especially representatives of the order Hymenoptera are often flower constant.
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The role of biotic interactions in population biology of meadow plants
Janovský, Zdeněk
In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....
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Changes in pollinator behaviour under different plant spatial aggregation
Štenc, Jakub ; Janovský, Zdeněk (advisor) ; Bartoš, Michael (referee)
Plants often occur aggregated into clusters and this spatial pattern is supposed to affect pollinator behaviour and pollen dispersal. Such pollinator reaction may influence reproductive success of zoogamous plant species both in terms of number of available mates and their genetic diversity (nearby growing plant individuals are also often closely related, especially in clonal plants). In the present thesis, I investigated the influence of plant spatial aggregation on pollinator behaviour and how this translates into pollen transfer. For that purpose, I carried three experiments. In the Experiment 1, I used potted plants placed into arrays and aggregated into four patches in order to track the pollen dispersal by means of a UV-dye pollen analogue. I manipulated distances between plants within clusters (dense × loose) and between clusters (near × far). I conducted this experiment for three plant species differing in their pollinator spectra. In the Experiment 2, I observed pollinator foraging sequences (sequences of visited plant individuals) under the same experimental design as for the first experiment, but I carried out this experiment for five plant species. In addition in one study species, Dianthus carthusianorum, I conducted the Experiment 3 to get better insight into pollination effectiveness...
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Pollinator pollen carryover effectiveness and plants' ability to enhance it
Freudenfeld, Martin ; Janovský, Zdeněk (advisor) ; Mikát, Michael (referee)
Pollinators carry over pollen from one flower to another. They facilitate plant reproduction. Pollinator functional groups differ in their effectiveness of pollen carryover. Quantity of pollen grains on their body and deposition on stigma are very important. Pollinator carryover capacity depends on its functional traits. Body size, hairiness, visitation behaviour, foraging preferences, flower constancy and abundance of pollinators are significant. Plants can enhance effectiveness of their pollination by adaptations to specific pollinator functional groups. They improve positioning of pollen on pollinators by specific changes to floral morphology, quantity and size of pollen grains. They can also enhance the effectiveness through aggregation of pollen grains into groups or into pollinia or by optimisation of pollen release in time.
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Pollinator movement and orientation at small spatial scales
Matoušková, Eva ; Janovský, Zdeněk (advisor) ; Tropek, Robert (referee)
Pollination is interesting andcomplex interaction between insects and plants which is essential for a wide spectrum of plants and animals. Hoverflies (Diptera: Syrphidae) and bees (Hymenoptera: Anthophila) are one of the most common pollinators in the Central Europe and are mostly involved in pollination of local plants. To maintain pollination, it is necessary the movement of pollinator from one flower of a specific species to another flower of the same species. This movement is affected by a number of factors based on both the environmental and pollinator traits. The aim of this work is to explore the nature of traits affecting pollinator flight between plants on small spatial scales, to classify the knowledge about the influence of pollinator and ambient effects to compare the differences between hoverflies and bees and suggest further possible fields of research. Keywords: pollination, hoverflies, bees, Syrphidae, Anthophila, movement
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Floral biology of temperate and tropical alpine plants
Nekola, Matyáš ; Sklenář, Petr (advisor) ; Janovský, Zdeněk (referee)
From all alpine ecosystems are tropic ones the most distinct, mainly due to aseasonality of their climate. In temperate alpine ecosystems seasonality causes annual changes in temperature and creation of snow cover. On the other hand, in tropical alpine ecosystems annual mean temperatures stay approximately same, but thanks to the high radiation heat loss at night temperatures vary significantly throughout the day diurnal. These environments also differ in change of day length throughout the year, altitude and atmospheric pressure. Plants created diverse adaptations in response to these different conditions. In temperate alpine ecosystems most of plants preform their floral primordia at least one year in advance. Flowering is initiated by photoperiod, temperature and combination of two previous factors, or immediately after the end of dormancy. Early flowering species are limited by the transfer of pollen and are allogamous. Late flowering species are autogamous. Main pollinators are from order Diptera. In tropical alpine ecosystems initiation of flowering correlates with decrease of minimal night temperatures and change in water availability. Asynchronously flowering species tend to be allogamous and autogamy prevails at synchronously flowering species. The most important pollinators are from genus...
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