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Ability to Discriminate Floral Morphotypes by Hoverflies
Matoušková, Eva ; Janovský, Zdeněk (advisor) ; Klečka, Jan (referee)
The attractiveness of flowers to pollinators is mediated by several floral traits. The ability to discriminate the flowers based on these floral traits is crucial for the flower reproduction and pollinator nutrition and reproduction. We tested three floral traits - colour, size and shape - along with their combinations using artificially 3D printed flowers on model organism Eristalis tenax in laboratory conditions. Our findings revealed that the most important floral trait was the colour followed by size. Additionally, the effect of colour was enhanced by size, but only for the preferred colour. This suggests that preferences for specific floral traits can be structured. The effect of symmetry was not significant. Subsequently, we observed non-naïve hoverflies and bumblebees in the field on flower patch consisting of devil's-bit scabious (Succisa pratensis). We were interested in the role of other floral traits when the colour and size were indistinguishable. The most important characteristics were height and effective number of florets in the inflorescence. The hoverflies tend to do longer visits than bumblebees and visited more flowers as well. Conversely, bumblebees did shorter but more efficient visits, likely due to their eusociality. Keywords: Syrphidae, Apidae, Eristalis tenax, Bombus spp.,...
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Diversity of floral functional traits and its seasonal changes in alpine environment
Plachtová, Kateřina ; Sklenář, Petr (advisor) ; Janeček, Štěpán (referee)
Floral functional traits characterize flowers and mediate contact between entomogamous flowers and their pollinators. Their form depends on many biotic and abiotic factors. The floral functional traits tend to be similar in high altitudes. However, the overall diversity of the floral functional traits does not vary significantly between altitudes. On the other hand, how temporal diversity of the floral functional traits varies during the flowering season was not studied yet. And this is the focus of this thesis. The aim of this study is to examine the hypothesis, whether the diversity of the floral functional traits changes in plant communities of alpine and montane meadows during the flowering season and also between them. The alpine and montane meadows are located in the area of Luční hora in the Krkonoše National Park. Morphological and spectral characteristics of the flowers were measured on both meadows. Abundance of flowering species and their flowers were measured every three weeks during five periods of the season. Diversity of the floral functional traits was obtained, for both meadows and all the measured periods of season, by weighting the floral functional traits with the species abundances. Using multivariate analysis, differences of temporal and altitudinal diversity were studied....
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Functional diversity of flowers in alpine plant communities
Plachtová, Kateřina ; Sklenář, Petr (advisor) ; Koupilová, Klára (referee)
Alpine environment differs from other biomes with its special abiotic conditions, which may influence local plant communities. Species composition of plant communities' changes along the altitudinal gradient. So do its vegetative and generative functional traits, as well as abundance and species composition of their pollinators. This thesis mainly examines floral functional traits (morphology, color and chemical traits of flowers) and their diversity along altitudinal gradient. It attempts to find general trends that characterize altitudinal changes of these traits. Most crucial drivers are pollinators and abiotic factors of environment. Functional traits of alpine plants change in response to variation in abundance and species composition of pollinators. Since dominant pollinators in the alpine environment are Diptera, floral functional traits of local plant communities are adjusted according to their preference. However, floral functional traits are also depending on abiotic factors, which can have an opposite effect compared to biotic factors. Considering the complexity of alpine plant communities and also the complexity of the drivers, which influence them, it's extremely difficult to find unambiguous patterns to describe these changes. Nevertheless, some trends in the altitudinal changes of...
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