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Multiproxy evidence of Late Pleistocene environmental changes in the loess/paleosol sequence of Bůhzdař
Flašarová, Kristýna
Loess-paleosol sequences preserve information that can be used to reconstruct paleoenvironement, specifically the climatic conditions and the vegetation present at the time of their formation. A dense network of reliably analyzed sequences from different geographic locations is crucial for representation of ecological and climatic trends during the Pleistocene (Frechen, 2011). The aim of this thesis is to fill the gap in the geographical distribution of well described loess-paleosol sequences in Central Europe. Therefore, it focuses on a loess- paleosol sequence in Bůhzdař, situated 9 km NW of Prague, Czech Republic. This profile was last studied in 1952 by naturalist Vojen Ložek. This thesis uses a number of analyses in order to get a multi-proxy record of local paleoenvironmental changes archived in a sequence of alternating loess sediments and paleosols in Bůhzdař. Geochemical approaches are combined with grain size distribution to define climatic conditions at the time of formation of the strata. Key words: loess/paleosol sequences, Bůhzdař, Czech Republic, particle size distribution, total organic carbon, XRF, XRD, stable isotopes 13 C and 18 O
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Separation and Elemental Composition of Tardigrades and Rotifers from Cryoconite in Svalbard
Jaroměřská, Tereza ; Žárský, Jakub (advisor) ; Šabacká, Marie (referee)
For years considered pristine, glacial ecosystems are attracting more attention of biologists from various branches in last decades. Moreover, they are currently considered to be ecosystems forming the coldest biome on the Earth. The life on glaciers ranges from viruses and bacteria to highest consumers such as few groups of microinvertebrates. The most common are tardigrades (phylum Tardigrada) and rotifers (phylum Rotifera) which inhabit cryoconite holes on the glacial surface. Several studies highlight the importance of the role of these consumers. However, due to the dominance of prokaryotes on the glacial surface, these microinvertebrates are usually out of the major scope of most studies aiming at biological processes. The present study shows pioneering results on the isotopic composition of tardigrades and rotifers, which are the top consumers in cryoconite ecosystems, and is a foundation for the exploration of trophic pathways and interactions within cryoconite holes using elemental and stable isotopic analyses. It also presents information about the species composition of tardigrades and rotifers on different glaciers and in different parts of the ablation zone. We identified 5 species of tardigrades (Hypsibius sp., Hypsibius cf. dujardini, Pilatobius sp., Isohypsibius sp. and Cryoconicus...
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Fish community trophic structure in antrhopogenically perturbed rivers
Dostál, David ; Horká, Petra (advisor) ; Jandová, Kateřina (referee)
Využití stabilních izotopů pro hodnocení trofické struktury společenstev nabývá v posledních dekádách na popularitě a stává se tak stále více používaným nástrojem užívaným k výzkumu trofických pozic a potravních nik. V této práci jsou shrnuty základní principy, které se při práci se stabilními izotopy využívají, představeny mechanismy výměny tkání, izotopového routingu a diskriminačního faktoru, jejichž zanedbání může vést až ke znehodnocení nabytých poznatků. Dále jsou v práci představeny základní metody využití stabilních izotopů, jejich výhody a nevýhody, matematické modely zpracování dat a jejich uvedení do praxe pomocí praktické části, ve kterém bylo zkoumáno trofické postavení a niky kaprovitých ryb v antropogenně ovlivněných řekách.
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Stable isotopes and the study of insects ecology
Javůrková, Jaroslava ; Šípek, Petr (advisor) ; Harant, Karel (referee)
Animal foraging ecology is an important part in the puzzle ecosystem relationships. This bachelor thesis presents review in the field of food ecology, especially insects. It focuses on the method of analysis of stable isotopes, which is one of the current and in recent decades a modern approach for studying this issue. Stable isotope analysis is compared with other frequently used methods for animal food ecology. The aim of this work is to introduce this method and its possible use in the study of insect food ecology. The first part provides the necessary theoretical background, practical application in laboratory and then it deals with the problems typically adressed by this method. Key words: stable isotopes, stable isotopes analysis, food ecology, food preferences, insects
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Atmospheric deposition of nitrogen - application of stable isotopes
Hanzlová, Barbora ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Human impact on particular parts of ecosystems has become a highly discussed topic. Due to different isotopic values of nitrogen, it is possible to evaluate the extent to which human influences the natural nitrogen cycle, using isotope measurements. Stable isotope measurement has been used in various scientific disciplines around the world. This thesis summarizes the findings about atmospheric deposition and the subsequent use of stable nitrogen isotopes. The objective of this work was to gather the information about the use of stable isotopes in the study of the atmospheric deposition and how to make better use of the information obtained from the measurements. Based on the literature review, it has been found that, unlike other countries, nitrate substances such as NH3 and HNO3 are not measured in the Czech Republic, which distorts the data on the nitrogen produced. The use of stable isotopes is a convenient method of measuring both not yet quantified substances as well as already measured substances contributing to atmospheric deposition. The stable isotope measurement method represents an improvement for the overall estimation of atmospheric deposition to provide more realistic values compared to the current approach. Key words: atmospheric deposition, nitrogen, stable isotopes
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What is the water contribution of fog to atmospheric deposition? Use of stable isotopes.
Hanusková, Darina ; Hůnová, Iva (advisor) ; Šantrůček, Jiří (referee)
The objective of the Master thesis is to estimate the fog contribution on atmospheric deposition with the usage of stable isotopes. The crucial part of the thesis was to perform (first of its kind in the Czech Republic) the relative isotope composition 18 O a 2 H of fog. In the same time, the composition of rain and throughfall was performed. The collection of each type of precipitation took place in five sampling points of Academy of Science within three mountain regions including Krkonoše, Šumava and Jizerské Hory during October and November 2017. The sampling took 14 days in total and it was performed by using TC/EA ThermoBremen and mass spectrometer Delta ThermoBremen at South Bohemian University in České Budějovice. The results confirmed that fog is isotopically heavier in comparison to regular rain. As for the relative isotope composition 18 O and 2 H of each areas, no significant difference was observed. Results of the fog participation on atmospheric deposition in Krkonoše and Šumava can be seen after drafting a simple linear mixing model. The fog contribution on atmospheric deposition in Šumava for 18 O is 4,7 % and for 2 H is 6,4 18 O. For one area in Krkonoše, the average participation for 18 O is 3,6 %. Key words: stable isotopes, oxygen, hydrogen, fog
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Pedogenic carbonates of loess-paleosol sequences
Máslo, Jaroslav ; Flašarová, Kristýna (advisor) ; Šefrna, Luděk (referee)
Loess is sediment composed predominantly os silt-size particles. Silt-size particles are transoported mainly by wind. Loess covers 10 % of earth surface. If the loess can be layed for a longer time when the glacials and interglacials alternate, the loess-paleosol sequences are created. Common part of loess and loess-paleosol sequences are pedogenic carbonates, which are particles of CaCO3. There are many types of carbonates, e.g. Calcified root cells. hypocoatings, needle-fiber calcite… Loess-paleosol sequences and carbonates in them are realy useful source of information about paleoenvirnonment. In practicle part of this work the isotopic composition of C and O in pedogenic carbonates from loess-paleosol sequence in Dejvice (Prague) was measured.
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Atmospheric deposition of nitrogen - application of stable isotopes
Hanzlová, Barbora ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Based on the literature review, the thesis summarizes the use of stable isotopes in the atmospheric deposition. According to the studies and empirical research, the origin and the extent of the pollution in the environment can be tracked down. Due to the different isotopic values, it is possible to evaluate the extent of human impact on the natural cycle of the ecosystem. Nitrogen can be found in all nature constituents where it gains different isotopic values. The objective of this work was to gather the information about the stable isotopes and to prove whether they are reliable indicators in determining the source of the nitrogen in the given area. By using the evaluated study, the difference in pollution within the coastal and continental areas in Central Europe was described. Keywords: atmospheric deposition, nitrogen cycle, stable nitrogen isotopes, fractionation
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Childhood diet in relation to the determination of social roles and health status in Great Moravian population
Jílková, Michaela ; Brůžek, Jaroslav (advisor) ; Kovačiková, Lenka (referee)
This study is focused on dietary reconstruction according to stable isotope analysis of carbon and nitrogen in bone and tooth collagen. The material used for this study is represented by set of 46 skeletons of adult individuals from 6th church's burial site in Mikulčice, which belong to the Great Moravian era (9th -10th century). Isotopic values are discussed in relation to the formation of social roles and health status. The presence and eventually degree of severity of some non-specific stress indicators and pathologies (Cribra orbitalia, presence of tooth caries, caries intensity, linear enamel hypoplasias, dental wear and length od femur) was observed. The results of isotopic analysis suggest, that diet in this population sample was based on terrestrial sources, both animal and plant protein. Plants in Great Moravian diet belonged to C3 and C4 group. C4 group of plants in Mikulčice was represented by millet (Panicum miliaceum), which supports the hypothesis of "Millet - typical crop of old Slavs" (Reitsema and Kozlowski, 2013). Millet was consumed mainly in childhood. Significant differences between diets of high social class and rest of population was found with people of higher social rank consuming more animal protein. These differences were created in childhood and persisted to adulthood....
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The use of stable isotopes in the trophic ecology of birds
Rusnáková, Michaela ; Hořák, David (advisor) ; Procházka, Petr (referee)
Recently, the use of stable isotope analysis has been becoming increasingly common in ecological studies of animals. This interesting method is based on the premise that the isotope composition of consumer's tissues is related to the isotope composition of the sustenance consumed. This allows us to explore the contribution of individual food sources to the diet of species, populations or individuals, and at the same time to study their position in the trophic chains. The method enables us to research even omnivores, consuming variable food with different nutrients and isotope composition. Nevertheless, isotope values can differ depending on diet preferences, species physiology and the tissue type used for the analysis. This review summarizes current knowledge and results in the topic of stable isotope analysis, particularly in ornithological studies where the approach in question has been used to study the diet and trophic position. Powered by TCPDF (www.tcpdf.org)
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