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Diptera in food webs of wetland ecosystems
Pijálková, Helena ; Hadrava, Jiří (advisor) ; Kolář, Vojtěch (referee)
Families of the order Diptera are frequently found in freshwater wetlands, affecting nearly all trophic levels, serving as detritivores, herbivores and predators. Diptera are characterised by an enormous ecological variability of their larval life strategies, which often differ even within individual families. Their adults form an important connection between the aquatic environment of a wetland with its terrestrial surroundings. As a result, adults of various wetland Diptera may serve as pollinators, predators and a prey of other animals including humans. Until now, research of food webs in wetland ecosystems has been focused mainly on a few economically significant groups of Diptera such as mosquitoes, or has been focused on the role of Diptera in transfer of heavy metal from wetlands to other ecosystems. However, overall wetland dipteran diversity still remains understudied. Examining the roles of insects as well as other organisms in food webs is important for example to simulate possible consequences of introduction or extinction of certain species on ecosystems. Further research is therefore necessary to understand how do various dipteran taxa affect other organisms in wetlands as well as their surroundings. Keywords: Diptera, wetlands, ecological webs, detritivory, herbivory, predation
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Dynamics of pollination networks in time and space
Matějková, Zuzana ; Hadrava, Jiří (advisor) ; Tropek, Robert (referee)
This bachelor's thesis focuses on changes in pollination networks on different spatio-temporal scales. It covers in detail the essence and magnitude of these changes in communities of pollinators and plants. The thesis outlines the consequences of these changes for these communities and the way it affects the methodological aspects of studying plant-pollinator networks. I present the existing dynamics of Pollination networks on broad geografical scales as well as changes in local communities. I also describe the temporal changes of communities of plants and pollinators, consisting of diurnal and seasonal dynamics, not exluding the changes on even broader temporal scales. It has been shown that plant-pollinator networks are highly dynamic in space and time. These dynamics consist of species and interaction turnover, as well as of changes in the overall diversity of communities of plants and pollinators. Biodiversity dependent characteristics of pollination networks are affected by the described spatio-temporal dynamics, while characteristics that are biodiversity independent stay relativly stable on broader temporal scales.
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