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Blackflies of the Czech Republic and their feeding preferences
Blechová, Karolína ; Brzoňová, Jana (advisor) ; Dvořák, Vít (referee)
Blackflies are globally distributed small flies belonging to the order Diptera, known as common nuisance for humans and vectors of certain parasites. The most commonly transmitted parasites include the genera Onchocerca, Leucocytozoon and Trypanosoma. For humans the most significant species is Onchocerca volvulus, which causes onchocerciasis (or "river blindness") in tropical areas. This thesis is about faunistics of blackflies in the Czech Republic, where was described 45 species of these flies to this date. First mentions of the family Simuliidae are from 19th century. More specific studies about these arthropods have been published since the 1950s and the main concern of these studies was to study blackflies at specific locations. More recent studies put focus primarly on blackflies as vectors. Host preferences are an important aspect in the characterization of blackflies and all vectors in general. Host preferences of blackflies are highly variable among species, ranging from ornitophilic blackflies tied strictly to a single host species (S. euryadminiculum with specifity on common loon) to opportunist species feeding on both mammals and birds (S. vernum). Host preferences have been adressed in only small number of studies. Classic method used for determination of host preference is...
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Drivers of ectomycorrhizal fungal species richness on large spatial scales
Petr, Andrej ; Kohout, Petr (advisor) ; Šímová, Irena (referee)
Ectomycorrhizal (EcM) fungi form mutualistic relationships with some woody gymnosperms and angiosperms that play an important role in the functioning of most terrestrial ecosystems. Using enzymes capable of sequestering nitrogen and phosphorus from complex organic compounds, EcM fungi make these elements available to their host plants, which in turn provide them with the carbon compounds on which EcM fungi are vitally dependent. However, different species of EcM fungi differ from each other in their ability to sequester nitrogen and phosphorus from organic compounds, as well as in their carbon requirements from plants. The importance of the EcM symbiosis for the ecosystem therefore depends on the species richness of the EcM fungi, which is influenced at large spatial scales by a number of interacting factors, in particular the density and diversity of host plants, climate and soil properties. As EcM fungi generally exhibit low host preference, the density of host vegetation and the associated higher nutrient availability for EcM fungi has a greater influence on their species richness on a global scale than the phylogenetic diversity of host plants. In addition to these environmental factors, however, the distribution of EcM fungi is strongly related to their biogeographic history. In the context of...
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