National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Evolutionary processes responsible for complexity in aquatic vascular plants
Prančl, Jan ; Kaplan, Zdeněk (advisor) ; Oberprieler, Christoph (referee) ; Štech, Milan (referee)
Aquatic plants are a heterogeneous assemblage of species that, although surviving in similar habitats, have evolved from very different genetic and ecological backgrounds. However, many aquatics share a number of anatomical, morphological, metabolic and reproductive adaptations, which have arisen independently in remarkable similarities (through convergence and parallelisms) in many unrelated groups. Despite their evolutionary uniqueness, aquatic plants are markedly underrepresented in contemporary biosystematic studies. Moreover, the taxonomic evaluation of numerous aquatic plant groups is intricate due to the strong morphological reduction and a high degree of phenotypic plasticity. This thesis focuses on two notoriously challenging aquatic plant groups, Callitriche and Ranunculus sect. Batrachium. The combination of several approaches (genome size estimation, chromosome counting, sequencing of nrDNA ITS and plastid trnT-trnL regions, examination of herbarium collections) was applied in order to improve our knowledge on principal evolutionary processes such as hybridization, polyploidization and cryptic variation and demonstrate their role on the shaping of overall aquatic plant diversity. The distribution of particular species in the Czech Republic was mapped for the first time. For both groups,...
Solar energy support in the Czech Republic in 2006-2016
Štěch, Martin ; Lukášová, Tereza (advisor) ; Maule, Petr (referee)
The aim of this bachelor thesis is to analyze the efficiency of solar energy support in the Czech Republic in 2006-2016. The paper shows the progressive development of photovoltaics, including economic and political impacts. Furthermore, the thesis deals with the position of the Czech Republic in the Europe 2020 program in terms of increasing the representation of renewable resources. The aim of the thesis is to find out whether there are negative externalities in supporting solar energy. In the theoretical part, the work is first devoted to the Czech Republic's energy sector, including renewable resources, energy policy and then to the development of the photovoltaic system. The practical part evaluates the efficiency of solar energy support in the Czech Republic in the chosen period. Support for solar energy seems to be economically inefficient both for the construction of large or small systems. The next part shows that the Czech Republic fulfills the criteria set by Europe 2020. The benefit of the thesis is the evaluation that solar energy support is not effective and causes negative externalities.
Influence of climatic fluctuations in Neogene/on evolution of ecologically diverse plant genus: an example of Hippophae L. (Elaeagnaceae)
Jia, Dongrui ; Bartish, Igor (advisor) ; Štech, Milan (referee) ; Comes, Hans-Peter (referee)
The Neogene geologic processes and climatic changes had tremendous impact on evolution of biota in different regions of Northern Hemisphere (NH). The Qinghai- Tibetan Plateau (QTP) was a central part of these processes. Migrations from the QTP to other temperate regions represent one of the main biogeographic patterns for Northern Hemisphere. However, this 'out-of-QTP' hypothesis has never been tested through a phylogeographic analysis of a widely distributed species and the ages and routs of these migrations are largely not resolved. On the other hand, climate change played an important role in shaping the amount and structure of intraspecific genetic diversity, which provide the main basic substrate for any evolutionary change. Therefore, a detailed understanding of the effects of historic climate alterations on intraspecific genetic diversity can provide valuable insights into the evolutionary consequences of past climate changes and predicting the likely direction of global warming effects on sustainability of extant populations and species. In this thesis, I first studied the phylogeography of Hippophae rhamnoides to test the 'out-of-QTP' hypothesis (Chapter II). Then, I performed phylogenetic, dating and biogeographic analyses of the genus Hippophae (Chapter III). Finally, I studied the...
Polyploid speciation of the genus Anthoxanthum in Europe
Khodlová, Zuzana ; Trávníček, Pavel (advisor) ; Štech, Milan (referee)
Eight of fifteen species in genus Anthoxanthum (Poaceae) can be found in Europe. Five of them are perennials forming A. odoratum complex, the remaining three are annual, more or less mediterranean taxa (A. aristatum, A. ovatum and A. gracile). Within the A. odoratum s. l. complex the following taxa are distinguished: widely spread A. odoratum s. str. (4x; 2n = 20), arcto-alpine A. alpinum (2x a 4x; 2n = 10 and 20), Madeiran endemic species A. maderense (2x; 2n = 10), endemic species of Balkan mountains A. pauciflorum (2x; 2n = 10) and the Iberian peninsula endemic A. amarum (?x; 2n ~ 90). The aim of this thesis is to clearify the unknown evolutionary relationships between the taxa, between the annuals and perennials, diploids and polyploids. The following questions should be answered in this study: 1) What is the origin and distribution of the rediscovered diploid perennial taxon and what is its relationship to the other members of the group; 2) What is the distribution pattern of the perennial taxa of the genus Anthoxanthum in Europe and what is their haplotype differenciation (overall distribution of the taxa and haplotypes and the existence of their sympatric occurence); 3) What evolutionary ties exist among the species and what is the origin of allotetraploid taxon A. odoratum s.str. The...
Phylogeography of temperate plant species with the focus on Central Europe
Daneck, Hana ; Marhold, Karol (advisor) ; Štech, Milan (referee) ; Tremetsberger, Karin (referee)
Phylogeography of temperate plant species with the focus on Central Europe Ph.D. Thesis Hana Daneck Charles University Prague Faculty of Science Department of Botany Supervisor: Prof. RNDr. Karol Marhold, CSc. Consultant: Mgr. Tomáš Fér, Ph.D. Praha 2012 2 Summary This thesis presents contribution to clarification of postglacial history of temperate plant taxa in Europe with the focus on especially interesting region of Central Europe, for which diverse roles in postglacial plant histories were suggested. The first part of the thesis summarises general phylogeographical views and methodological approaches with the respect to species history after the last ice age in Europe. Further, the most important aspects of phylogeography of European temperate plant taxa are discussed. The second part contains a set of papers dealing with selected European temperate plant species, for which phylogeographical patterns throughout their present distribution area were inferred, including assumptions on the origin of their contemporary Central European populations and comparisons with another previously studied species. Paper 1: Phylogeographic pattern of the European forest grass species Hordelymus europaeus: cpDNA evidence. This paper presents phylogeographical pattern based on chloroplast haplotype variation covering the...
Aquatic and wetland plants: taxa, communities and relationships
Štech, M. ; Hroudová, Zdenka ; Kaplan, Zdeněk ; Hrouda, L.
Edited volume on aquatic and wetland plants, with emphasis on taxa, communities and relationships.
Work results of flora of Třeboň basin
Kurka, R. ; Husák, Štěpán ; Štech, M. ; Pípalová, I.
The paper content of conception of Flora of Třeboň basin as well as of authors proposal for individual chapters.

National Repository of Grey Literature : 11 records found   1 - 10next  jump to record:
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1 Štěch, Martin
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