|
|
Autecological study of selected Cretaceous plants using stable Carbon isotopes
Zahajská, Petra ; Kvaček, Jiří (advisor) ; Diefendorf, Aaron (referee)
1 Abstract This thesis presents an analysis of fossil plants from the Cenomanian Peruc-Korycany Formation of the Bohemian Cretaceous Basin and from the Bückeberg Formation of the Lower Saxony Basin in Germany. Based on earlier studies, both areas provide sediments that are considered to have developed in tidally influenced fluvial systems. Studied fossil plants are represented by ginkgoalean plant leaves (Ertemophyllum, Tritaenia), branches of conifers (Frenelopsis) and lauroid angiosperms (Eucalyptolaurus). Frenelopsis, Eretmophyllum and Tritaenia are considered to be halophytic plants, while Lauroid angiosperms were considered to grow in fresh water conditions. The fossil plants were studied using cuticle analysis and two methods of stable carbon isotope analysis: Bulk carbon isotope analysis and Compound Specific Isotope analysis. For cuticle analysis samples were observed and documented macroscopically and microscopically. To specify the environmental conditions, recent samples from three salt marshes in Great Britain were studied and analysed using the same methods as the fossil samples. The data from all observations and measurements were processed and their interpretation supported the modelled environment based on the sedimentological data. Frenelopsis were growing in a haline environment with low...
|
|
| |
|
|
Mycorrhisa in fossil record
Kadlecová, Veronika ; Kvaček, Jiří (advisor) ; Gryndler, Milan (referee)
Mycorrhizal symbiosis is present in the vast majority of extant land plants. Mycorrhizae represent a significant source of nutrients for both partners of the symbiosis and can also provide them with protection or help them survive in less hospitable enviroment. Mycorrhizae is believed to have been just as important in the past and played a major role in evolution of plants, for example in the transition of plants onto land. Mycorrhizal symbiosis is an object of many research works today for its agricultural importance. There is an amount of publications on research of fossil mycorrhizae, but there is still little interest in this issue. Powered by TCPDF (www.tcpdf.org)
|
|
|
Forced passage of participating securities
Kvaček, Jiří ; Černá, Stanislava (advisor) ; Zahradníčková, Marie (referee)
This rigorous thesis deals with the topic of the forced passage of participating securities in a joint stock company as regulated by Act No. 90/2012 Coll., on Business Companies and Cooperatives (Act on Business Corporations), as amended, that has been extensively amended with effect from 1 January 2021. The purpose of this thesis is to conduct an in-depth legal analysis of the amended legislation, inter alia, by using the case law of the Czech courts, to draw attention to the shortcomings and ambiguities of the legislation, to suggest possible solutions and to try to identify the most appropriate one. In order to clarify the thesis, the text is divided into several chapters, of which every chapter contains an in-depth analysis of individual parts of the examined problematics, which can be understood as relatively separate areas. The chapters are further divided into subchapters. The first chapter is devoted to the explanation of the basic terms and instruments that are inseparably linked with the forced passage of participating securities. Understanding these terms and instruments is crucial for understanding the complex problematics of the forced passage of participating securities in general. The second chapter examines the problematics of the constitutional conformity of the legislation and...
|
|
|
Paleoecological study of the Cretaceous extremophilic flora with emphasis on xerophytes
Čepičková, Jana ; Kvaček, Jiří (advisor) ; Teodoridis, Vasilis (referee)
Thestudied materialcomesfromtheBohemianCretaceousBasin,Peruc-Korycany FormationCenomanianage,fromthelocalitiesPecínovandPraha-MaláChuchle. Recent plantswereusedforcomparisonwithfossilxeropyhteandmesophyteplants.Fossilandrecent materialwasmacromorphologicallydocumentedandanalyzedusingcuticularanalysis. Inthesystematic part, elevenfossiltaxafromdivisions Lyginopteridophyta, Cycadophyta,Ginkgophyta,Pinophytaand Magnoliophytaweredescribed.Fromthese,three newtaxawereestablished:bennetiteleafofZamitesmirovanaesp.nov.,angiospermleavesof Dicotylophyllumlabutae sp. nov.andD. pecinovense sp. nov. Based onthestudy of macro-and micro-morphology,it wasdistinguished whichpartofthestudied material belongstotheextremophytes.Observationsofmicromorphologyshowedthatplantsthatwere exposedto waterstress weretryingto overcome thisconstraint byadjustingtheir micromorphology. Analysingpreviouslypublishedandnewlyacquireddatahelpedtoseparatehalophytes fromotherstudiedfossiltaxa.Theseplantsfromtheenvironmentofsaltymarshesandtide- influencedswampsarecharacterisedbythickcuticle,stomataembeddedinstomatalchamber and/orsurroundedbyraisedrimsorpapillae.Theyshowvariousformsofwrinklesorpapillae ontheir externalsurface ofepidermisandarecomparativelyabundantin sediments ofthePeruc-KorycanyFormation.Theboundarybetween...
|
|
|
Study of fungi, algae and bryophytes from the Cretaceous of the Bohemian Massif and James Ross Island
Kadlecová, Veronika ; Kvaček, Jiří (advisor) ; Pšenička, Josef (referee)
The objective of this Diploma thesis is study of diversity of Late Cretaceous bryophytes, fungi and algae from selected localities of the Bohemian Massif and James Ross Island. The focus of the study is the most precise taxonomy assessment of the found fossils and comparsion of their diversity in selected localities from the Northern and the Southern hemispheres. The greatest emphasis is focused on bryophytes, but algae and fungi are mentioned as well. Thereare described two species of fungi, compared to recent genera Passalora and Stomiopeltis, one species of algaea ssigned to Phycopeltis, two species of liverworts assigned to Ricciopsis, one species of incertae sedis and two species of mosses assigned to Muscites and Livingstonites from the Bohemian Massif. Additionally, from James Ross Island there are three species of mosses described and assigned to Muscites and Livingstonites.
|
|
|
Paleoecological study of the Cretaceous extremophilic flora with emphasis on xerophytes
Čepičková, Jana ; Kvaček, Jiří (advisor) ; Teodoridis, Vasilis (referee)
Thestudied materialcomesfromtheBohemianCretaceousBasin,Peruc-Korycany FormationCenomanianage,fromthelocalitiesPecínovandPraha-MaláChuchle. Recent plantswereusedforcomparisonwithfossilxeropyhteandmesophyteplants.Fossilandrecent materialwasmacromorphologicallydocumentedandanalyzedusingcuticularanalysis. Inthesystematic part, elevenfossiltaxafromdivisions Lyginopteridophyta, Cycadophyta,Ginkgophyta,Pinophytaand Magnoliophytaweredescribed.Fromthese,three newtaxawereestablished:bennetiteleafofZamitesmirovanaesp.nov.,angiospermleavesof Dicotylophyllumlabutae sp. nov.andD. pecinovense sp. nov. Based onthestudy of macro-and micro-morphology,it wasdistinguished whichpartofthestudied material belongstotheextremophytes.Observationsofmicromorphologyshowedthatplantsthatwere exposedto waterstress weretryingto overcome thisconstraint byadjustingtheir micromorphology. Analysingpreviouslypublishedandnewlyacquireddatahelpedtoseparatehalophytes fromotherstudiedfossiltaxa.Theseplantsfromtheenvironmentofsaltymarshesandtide- influencedswampsarecharacterisedbythickcuticle,stomataembeddedinstomatalchamber and/orsurroundedbyraisedrimsorpapillae.Theyshowvariousformsofwrinklesorpapillae ontheir externalsurface ofepidermisandarecomparativelyabundantin sediments ofthePeruc-KorycanyFormation.Theboundarybetween...
|
|
| |
|
|
Sphenopterid type of true ferns from Carboniferous basins of Czech massive
Frojdová, Jana ; Pšenička, Josef (advisor) ; Kvaček, Jiří (referee) ; Rößler, Ronny (referee)
This thesis deals with the sphenopterid types of ferns from the Czech Carboniferous basins. Thesis is presented as a combination of two published papers in peer-reviewed journals, one manuscript in review and one manuscript ready for submission. The actual text of the thesis is a general introduction with introduction to the study subject of sphenopterid ferns, methodology, studied type collections, terminology and the result of my study. The introduction of the thesis provides a general overview of the ferns and history of their studies. All four papers presented here are focussed on modern redescription, redefinition, emendation and revision of genera Boweria Kidston, Dendraena Němejc, Sturia Němejc. Based on the revision of these genera, following two new genera were established: Kidstoniopteris gen.nov. and Paraszea gen.nov. A new species Boweria nowarudensis has been described during the course of this study. The "whole plant concept" was applied to all studied specimens, which allows to obtain as much information on the ferns morphology, anatomy, and reproductive organs as possible. This was combined with data on in situ spores as well as sedimentological and petrological analyses. The sporangial cells as annulus, stomium and apical cells and in situ spores were described for all genera and...
|
|
|
Early vascular plants in the Czech Republic
Uhlířová, Monika ; Kvaček, Jiří (advisor) ; Opluštil, Stanislav (referee)
Vascular plants are characterized as a group of plants, which are already fully adapted to live on the land. Their evolution is a result of a set of adaptations that have required the necessary changes at anatomical and morphological level. Some evidences about the rise of vascular plants appear in the fossil record from the Middle Ordovician in the form of spores and later also from the Early Silurian in the form of megafossils. The aim of the thesis is to briefly describe and discuss the most important published findings of fossils, especially megafossils, of the early vascular plants from the Silurian. Interest is especially focused on published material from the Czech Republic. The thesis also includes more detailed description of the genus Cooksonia, representing the first vascular plants, which are discovered in the megafossil record. Key words: vascular plants, spores, megafossils, Silurian
|
guest ::
RSS feed.