|
|
Phylogeography and genetic variation of benthic crustaceans in European inland waters
Pešek, Pavel ; Petrusek, Adam (advisor) ; Sacherová, Veronika (referee)
This thesis summarises published information about geographic distribution of genealogical lineages and genetic variability of benthic crustaceans of European continental waters, and evaluates the historical factors that affected their distribution. it is focused mainly on species for which multiple or in-depth studies have been published. A particular attention is given to crayfish of the genus Austropotamobius. Present distribution of genealogical lineages has been affected by changes in connectedness and availability of aquatic habitats. Species lineages often split in consequence to geological and climatic processes during the Tertiary, as exemplified on species complexes of Austropotamobius crayfish, species lineages of the amphipod Gammarus fossarum species complex, and the isopod Asellus aquaticus. The distribution of intraspecific lineages has been strongly affected by Quaternary cycles of glaciation, which not only destroyed many habitats by moving glaciers but also created new colonisation routes. Such routes were peri-glacial lakes, which had been used by Gammarus lacustris, or retreat of sea level, which enabled white-clawed crayfish to colonise England, and a freshwater crab to colonise Italy. Changes in sea levels are also the likely reasons for colonisation of continental waters by the...
|
|
|
Western Carpathians as diversity hotspot during the Quaternary climatic cycle
Kubíková, Kateřina ; Juřičková, Lucie (advisor) ; Horáček, Ivan (referee)
In the context of the entire Europe, the Western Carpathians is a unique area of priceless biological significance. Topological complexity, together with significant climatic and edaphic variability, is reflected in the high habitat heterogeneity and has enabled the survival of a large number of species in this area during the Quaternary climatic cycle. The Western Carpathians thus represents one of the most important glacial as well as interglacial refugium in Europe. The result of these environmental variables and the unique history of this region is an enormous species diversity, a high degree of endemism and the occurrence of many glacial relics. This bachelor's thesis contains a review of mainly zoological studies dealing with high biodiversity and degree of endemism in the Western Carpathians and its possible causes. The role of the Western Carpathians as an important Pleistocene refugium, its influence on other parts of Europe and the postglacial development of the area are discussed in individual chapters.
|
|
|
Agrární terasy jako refugium xerotermních organismů - příklad z okolí Veverských Knínic
Hamřík, Tomáš
The main aim of this bachelor thesis is to explore if agrarian terraces provide a suitable refuge for xerothermic species of spiders. Two slopes within the agrarian terraces area near Veverské Knínice, which are used for growing arable crops, were chosen for the research. Spiders were chosen as a bioindicative, model organism. The spiders were collected using pitfall traps, which were placed in three succession stages: sparse, dense grass turf and bush. Eighteen pitfall traps were placed in six lines. One line consisted of three traps and each of the lines was placed in a different succesion stage. The collection was carried out eight times on the following days: 19. 6. 2014, 24. 7. 2014, 29. 8. 2014, 6. 10. 2014, 20. 11. 2014, 3. 6. 2015 and 29. 6. 2015. Overall, 635 samples were collected and identified as 66 species of 44 genus and 16 families. Altogether, 40 xerothermic species were collected, with five of these species listed on the Red List of Czech spiders (VU = 4, EN = 1). These species were: Micaria formicaria, Nematogmus sanguinolentus, Neottiura suaveolens a Xysticus striatipes, which are typical for steppes or forest-steppes. The most significant finding was Sibianor tantulus, recorded within the Czech Republic only for the third time. The statistical Analyses of Variance found that the type of succesion stage does not affect the number of species observed. Species of spiders are evenly spread within terraces. This means that it is very important to preserve a mosaic of habitats within slopes of agrarian terraces. The results indisputably demonstrate the conservation value of agrarian terraces as a refuge for xerothermic organisms.
|
|
|
Phylogeography and genetic variation of benthic crustaceans in European inland waters
Pešek, Pavel ; Petrusek, Adam (advisor) ; Sacherová, Veronika (referee)
This thesis summarises published information about geographic distribution of genealogical lineages and genetic variability of benthic crustaceans of European continental waters, and evaluates the historical factors that affected their distribution. it is focused mainly on species for which multiple or in-depth studies have been published. A particular attention is given to crayfish of the genus Austropotamobius. Present distribution of genealogical lineages has been affected by changes in connectedness and availability of aquatic habitats. Species lineages often split in consequence to geological and climatic processes during the Tertiary, as exemplified on species complexes of Austropotamobius crayfish, species lineages of the amphipod Gammarus fossarum species complex, and the isopod Asellus aquaticus. The distribution of intraspecific lineages has been strongly affected by Quaternary cycles of glaciation, which not only destroyed many habitats by moving glaciers but also created new colonisation routes. Such routes were peri-glacial lakes, which had been used by Gammarus lacustris, or retreat of sea level, which enabled white-clawed crayfish to colonise England, and a freshwater crab to colonise Italy. Changes in sea levels are also the likely reasons for colonisation of continental waters by the...
|
|
|
Spontaneous succession of vegetation of abandoned quarries in the Bohemian Karst: Occurrence of species in quarries and their surroundings
KAREŠOVÁ, Petra
Variation of vegetation during spontanneous succession was researched in ten limestone quarries in the Bohemian Karst in central part of the Czech Republic. Five abandoned quarries surrounded by woodland and five quarries with grassland prevailing in the surroundings were chosen. The age of quarries varied from 33 to 97 years. The complete list of plant species was recorded for each quarry and near surroundings (up to 100m).Resulting analyses demonstrated the close relationship between the occurrence of species in the quarries and their surroundings. The quarries may act as refugia for rare and retreating specie
|
guest ::
