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Determinants of orchid species diversity
Štípková, Zuzana ; Kindlmann, Pavel (advisor) ; Kull, Tiiu (referee) ; Whigham, Dennis (referee)
Natural environment has been significantly altered by human activity in past few decades. There is an evidence that we are now facing the sixth mass extinction and suitable areas for species are getting smaller. Therefore, many species of plants and animals are experiencing strong population decline and some of them even became extinct. We focused our attention on orchids because their distribution expresses one of the highest declines among all plant families. In this thesis, we investigated species richness and distribution patterns of orchids, the rate and causes of their decrease and extinction, and factors influencing their occurrence in the Czech Republic and Greece. In the majority of the presented papers, we used a dataset based on the database of the Nature Conservation Agency of the Czech Republic that includes more than 115 000 of orchid records in the country. We also analysed the patterns in the six different phytogeographical regions in the Czech Republic that differ in altitude and the composition of local flora. The key findings are as follows: The specialized pollination strategy of orchids, as well as type of rooting systems, both in the Czech Republic and in Greece, play a role in the distribution patterns of orchids in the two countries (Papers I, II and VI). Moreover, the...
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Ecology of orchids and other potential pharmaceutical plants in Nepal
Rokaya Timsina, Binu ; Kindlmann, Pavel (advisor) ; Whigham, Dennis (referee) ; Kull, Tiiu (referee)
In this thesis, I focused mainly on orchids and also carried out some research on different pharmaceutically potential plants in Nepal. I compiled both data from field and secondary data sources and one of my first outputs was complete checklist of orchids in Nepal. I also studied distribution patterns and affinities of orchids with different floristic regions in Nepal. My next work on epiphytic orchids is related to diversity, distribution and host- species associations and their future in the context of climate change in Nepal. In addition to this, I also worked on factors affecting epiphytic orchids along an altitudinal gradient in central Nepal. Working on population dynamics of terrestrial orchid species, Crepidium acuminatum, lasted for 6 years. Together with orchids, I determined secondary compounds present in a highly important Nepal endemic medicinal plant, Swertia multicaulis. I also compiled the information on uses, phytochemistry, pharmacology and toxicity of highly important Himalayan endemic medicinal plant, Neopicrorhiza scrophulariiflora. The last research of my Ph.D. project ended up by gathering the information on uses of different medicinal plants, including orchids that were used to treat various gastrointestinal diseases in Nepal. The results of my doctoral thesis are presented...
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