|
|
Taxonomy, ecology and biogeography of aquatic and limno-terrestrial diatoms (Bacillariophyta) in the Maritime Antartic Region
Kopalová, Kateřina ; Nedbalová, Linda (advisor) ; Sabbe, Koen (referee) ; Jüttner, Ingrid (referee)
Diatoms (Bacillariophyta) are one of the most diverse algal groups in the Antarctic Region and play a dominant role in almost all freshwater and terrestrial ecosystems. Despite this overall occurrence, little is known about the diversity, ecology and biogeography of this group in the Maritime Antarctic Region. The main objective of this thesis is therefore to define the taxonomical, ecological and biogeographical characterisation of aquatic, semi- aquatic and moss-inhabiting diatom communities from two islands in the Maritime Antarctic Region: James Ross Island and Livingston Island, located on opposite sides of the Antarctic Peninsula. In this study, a total of 250 samples from three different habitat types (lakes, streams & seepage areas and mosses) from Byers Peninsula (Livingston Island) and Ulu Peninsula (James Ross Island) have been analysed. Using light and scanning electron microscopy, a rather diverse diatom flora composed of 178 taxa, belonging to 43 genera has been identified. Although even until recently, it was generally accepted that the Antarctic diatom flora was mostly composed of cosmopolitan taxa, several new species could be described as a new for science during this PhD study (a reflection of this work is presented in chapters 2 & 3 and in Appendices). Habitat type and...
|
|
|
Unveiling hidden species diversity in desmids (Desmidiales, Viridiplantae)
Šťastný, Jan ; Neustupa, Jiří (advisor) ; F.M. Coesel, Peter (referee) ; Kaštovský, Jan (referee)
The delineation of desmid species was traditionally based on purely morphological features. However, a frequent misinterpretation of morphological variability in desmids has led in the past to extensive taxonomical confusion within this important group of green algae which complicates the interpretation of their biodiversity in freshwater ecology, biogeography and biomonitoring. Consequently, I focused in this thesis predominantly on a previously neglected issue, the application of polyphasic approaches in the species-level taxonomy of desmids. In the most studies, a combination of both traditional morphological and modern molecular phylogenetic and geometric morphometric methods has been used to evaluate the taxonomy of selected desmid species, particularly representatives of the morphologically complex genera Micrasterias and Xanthidium. In two papers, I used the combination of traditional morphological and autecological data to clear up the taxonomy of several morphologically less prominent desmid taxa. Generally, the results of the thesis demonstrated that the way we recently see the diversity and distribution of desmids should be thoroughly changed. The real species diversity is mostly distinctly finer than that estimated by classical morphological taxonomy, often corresponds to varieties of...
|
|
|
Phylogenetic, morphological and ecological context of microevolution in pennate diatoms
Veselá, Jana ; Neustupa, Jiří (advisor) ; Řeháková, Klára (referee) ; Vanormelingen, Pieter (referee)
Visual assessment of discontinuities in the morphological features of diatom cells has been widely used in the discovery and delimitation of diatom species. However, a multidisciplinary approach to species-level taxonomy has revealed hidden diversity within the traditional diatom morphospecies. Consequently, this work examined both the natural and clonal populations of diatoms by diverse traditional and modern approaches, in order to assess the diversity, ecology, and distribution of diatom species. Although a detailed investigation of natural diatom samples was confounded by uncertain morphological boundaries between the traditional diatom species, it recognized that the diversity was relatively high; even one new diatom species was described using the morphological species concept. The multivariate statistical analyses showed that the variation of natural communities of traditional diatom morphospecies reflected differences in the local environmental conditions, as well as microhabitat heterogenity within a region. Since each diatom morphospecies is most likely a complex of sibling species, the two model traditional morphospecies were investigated, in order to assess morphological variation, genetic diversity, and/or the reproductive compatibility of monoclonal cultures. Even though isolated...
|
|
|
Biogeography, diversity and substrate specificity of aeroterrestrial green algal genus Klebsormidium (Streptophyta)
Ryšánek, David ; Škaloud, Pavel (advisor) ; Mareš, Jan (referee)
Filamentous aeroterestrial green algae genus Klebsormidium occurs in a very wide range of freshwater and terrestrial habitats. Recent results of molecular investigations led to the finding that the diversity within this genus is far greater than expected on the basis of the morphological features, and that the traditional phenotypic species concept is insufficient. I tried to differentiate phylogenetic lineages within the genus Klebsormidium by thein different biogeographical distribution and environmental preferences. Since no study dealing with the biogeographic pattern of aeroterrestrial algae was so far undertaken, another aim of this work was to test validity of the protist ubiquity model in aeroterrestrial habitats. I studied this issues based on the chloroplast rbcL molecular marker. Based on the obtained data I found that the geographic definition of particular Klebsormidium lineages turns out to be unusable because of the cosmopolitan occurrence of almost all genotypes. However, the data obtained from the substrate specificity study shows that clear ecological preferences exist within the genus Klebsormidium and could be simply used to define different lineages within the genus.
|
|
|
Biogeografie zázvorovitých z podčeledi Alpinioideae
Hlavatá, Kristýna ; Fér, Tomáš (advisor) ; Záveská, Eliška (referee)
This work aims to summarise the recent knowledge of the distribution of the subfamily Alpinioideae and suggest the possible patterns of distribution and dispersal for individual genera, particularly for South-East Asia, where the majority of genera is found. Alpinioideae is a quite recently established and unresolved group and some of its genera are polyphyletic. The main part of the subfamily is distributed throughout South-East Asia to Australia and Oceania, two genera (Aframomum and Renealmia) are found in Africa and the genus Renealmia has undergone long-distance dispersal to South America. Three genera (Leptosolena, Paramomum and Siamanthus) are monotypic endemics. Alpinioideae is further divided into the tribes Alpinieae and Riedelieae.
|
|
|
Biogeography and specificity of Asterochloris photobionts
Řídká, Tereza ; Škaloud, Pavel (advisor) ; Vondrák, Jan (referee)
This diploma thesis has focused on the diversity and biogeography of Asterochloris photobionts. Since no study so far has been published on the biogeography of symbiotic microorganisms, the presented thesis is the first attemp to trace the biogeographic distribution and endemism of symbionts. By gathering 121 Asterochloris sequences obtained from lichen thalli sampled outside Europe and America, the diversity within the genus increased dramatically. The phylogenetic analysis based on the concatenated alignment of ITS rDNA and actin sequences obtained from Cladonia and Stereocaulon photobionts revealed 28 differently supported clades. Of them, eight lineages were newly discovered. Three environmental factors explaining the best the distribution pattern of Asterochloris photobionts were selected according to the statistical tests of the phylogenetic signal: two different types of biogeographical ecoregions and the substrate type. In general, the genus Asterochloris is distributed cosmopolitally, with a very low rate of endemism. Newly obtained data indicate that the restricted distribution of any photobiont clade is not caused by either historic or biological factors, but more likely by specific climatic or habitat preferences.
|
|
|
Gondwanian element of Latin American Flora
Potůčková, Anna ; Stančík, Daniel (advisor) ; Kvaček, Jiří (referee)
The concept of plate tectonics accepted during 20th century fundamentally changed general opinion on the origin of Latin American flora. It was found, that South America formed a part of the ancient continent Gondwana. This continent was covered by a unique flora until 100 million years ago. Actual disjunction of widely distributed tropical taxa present in South America originated after disruption of that original flora distribution. It was deduced that the separation of South America from Gondwana finished about 100 million years ago and led to the isolation of their flora until the formation of the Isthmus of Panama about 3 million years ago. However, recent studies based on molecular clock approaches shows that the exchange of biota between South America and rest of the World was possible several times in different ways before the closure of the Isthmus of Panama. The reevaluation of our opinion about the gondwanan origin of Latin American flora based on advanced molecular analysis is the aim of this work.
|
|
|
Diversity and distribution of scorpions (Arahnida: Scorpiones)
Plíšková, Jana ; Šťáhlavský, František (advisor) ; Kůrka, Antonín (referee)
This thesis is devoted to species diversity and biogeography of Scorpiones order. Bachelor work is presenting basic problems of this area and major split in higher classification of scorpions, which is still not firmly defined. In the work is also provided an overview of the current 15 families, to whom is the scorpions order divided by classification proposed by Soleglad & Fet (2003), including their distribution, the number of families and species they cover. Factors which had or still have an impact on the expansion of scorpions are also discussed. Described factors, which affects the distribution and diversity of scorpions, are: continental drift and Quaternary climate change (historical aspects) and temperature, parthenogenesis and human factor (environmental aspects). These factors influenced the biogeography of scorpions at different taxonomic levels, in different evolution time scale and on differently sized territories.
|
|
|
Small mammals in diet of barn owl in the Eastern Meditarranean
Šindelář, Jiří ; Horáček, Ivan (advisor) ; Anděra, Miloš (referee)
The extensive material of skeletal remains of mammals from a diet of barn owl in the eastern Mediterranean has been processed and evaluated with different techniques of chorological and morphometric analysis. At least 8400 individuals of 45 species of insectivores, rodents and bats were found in our total collection of samples, which represents a significant portion of fauna of the region. We have evaluated a chorological composition of the taphocoenoses and the interregional differences, manifested primarily by differences in the representation of satellite and accessory elements. We found a highly significant impoverishment of the isolated island taphocenoses (Cyprus, Karpathos, partly on Crete), where Cricetidae, Arvicolidae, C. leucodon etc. are missing. On the other hand the essential part of the dominance structure takes up the Rattus rattus, which acts here as an invasive species, significantly more successful than in the ragged continental contexts. The species diversity of the examined samples is positively correlated with the geographic latitude (taphocenoses of the northern regions are significantly richer) and negatively with the island effect and the degree of aridization. The morphometric analysis of the three most abundant species of Soricidae within the studied region showed...
|
|
| |
guest ::
