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Phylogeography and conservation genetics of rare palearctic megaherbivores
Červeňák, Jakub ; Hulva, Pavel (advisor) ; Robovský, Jan (referee)
This review is focused on the surviving species of Pleistocene megaherbivores in the Palearctic realm. It describes a basic classification of herbivores depending on their trophic niche, the adaptations associated with diet and an application of Cope's rule in evolution of ungulates. This is followed by a description of different approaches in defining megafauna and causes of large animals extinctions at the end of the Pleistocene and during the Holocene. At the end of the general part of this work, the importance of megafaunal elements as keystone species and concepts of downsizing, associated trophic downgrading and the idea of rewilding are being emphasized. In the second part of the work, Pleistocene history, phylogeography and marked reduction of range during the Holocene are described for elk (Alces alces), European bison (Bison bonasus) and Przewalski's horse (Equus przewalskii) according to the available literature. Finally, a history of the efforts to save the species and current knowledge on conservation genetics related to an overcome bottleneck effect are ascertained. Key words: Pleistocene megafauna, bottleneck, reintroduction, rewilding, browsing, grazing
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Epizoochorous dispersal of vascular plants by large mammals
Mádrová, Terezie ; Lepková, Barbora (advisor) ; Vlasta, Tomáš (referee)
Epizoochorous dispersal is together with endozoochorous dispersal one of the two basic principles of zoochory - the seed dispersion by animals. Epizoochory is defined as the spread of seeds by attachment to the surface of animals, for example in the fur of mammals, feathers of birds, even on the surface of the human clothing if we consider human as dispersal vector. There are plant species, which adapted to the epizoochory during the evolution. We can observe their morphological adaptation such as hooks, various appendages or mucilage. However, the efficiency of these adaptations, also depends on the type of the carrier, which can be either a mammal (for example ungulates or carnivores), bird or a reptile. Epizoochory also has an impact on the biodiversity - it is a mechanism that can spread the seeds across long distances and therefore provide the species variability in the environment. Today it is also an efficient way of dispersion in the fragmented landscape, where the plants are dispersed together with the animals between the fragments of vegetation. Rewilding, which is a method of returning the keystone species into the landscape and therefore restoring the interrupted natural processes, is also related to changes in the landscape. Keywords: epizoochory, seed dispersal, large herbivores,...
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