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Investigating associations of saproxylic beetles with forest structure through the analysis of species composition and feeding guilds
KOZEL, Petr
The thesis contains studies focusing on various forest biotopes of Central Europe and saproxylic beetles as a model group for forest ecology research. In the review, current knowledge about the threats for forest biota, mainly saproxylic beetles are discussed in the context of species composition and trait-based approach. Various stages of succession in the patches of disturbed forests, their connectivity, the introduction non-native tree species, and the assessment of feeding guilds using stable isotopes are studied in the relation to saproxylic beetles in separate chapters.
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Evaluation of runoff formation in catchment using stable isotopes 2H and 18O and water temperature
Hojovec, Daniel ; Vlček, Lukáš (advisor) ; Jeníček, Michal (referee)
The evaluation of the water regime of the springs, or the total runoff in small mountain catchments, is an important aspect in this work for understanding the functioning of the catchment from the point of view of the precipitation-runoff process, and above all for the verification or refutation of the various methods used to evaluate the runoff of the mountain catchment. For the stated purposes, between 2018 and 2020, repeated sampling was carried out from water courses, soil (shallow wells) and precipitation in the Rokytka catchment area. From the obtained data, the ratio of stable isotopes 2 H and 18 O was subsequently determined in the laboratory. We also worked with the data of stable isotopes 2H and 18O provided by the Department of Physical Geography and Geoecology of the Faculty of Natural Sciences of Charles University for the period 2014-2018. All data, together with hydro-meteorological data, were subjected to various analyzes and methods with the aim of evaluating the runoff. The core method of this work was hydrogram separation using a mixing equation working with stable 2 H isotopes and water temperature for 6 events. On the basis of the performed analyzes and hydrographic separations, it was found that the water in the Rokytka přítok during significant rainfall-runoff events is...
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Ecological consequences of seasonal bird migration
Brlík, Vojtěch
Environmental seasonality, and associated fluctuation in resource abundance, affects organisms throughout their life cycles. Periods of resource scarcity can be avoided by seasonal migration, strategy common in animals, including birds. However, the long journeys of migratory birds separate the stages of their annual cycles in space and time, and present them with a variety of challenges. Environmental conditions that migrants experience may have local effects, or may carry over across seasons, and have delayed impacts on individuals and populations. To better understand the interactions between migratory animals and their environment, we integrated individual tracking, environmental measures, and population data within a full annual cycle perspective. We contributed to the understanding that environmental conditions can affect migratory populations both en route and during stationary non-breeding periods, and that their effects can be observed on a continental scale. We also showed, across species and migratory flyways, that stages of the annual cycle are tightly linked during migration, but that these links weaken during prolonged non-breeding stationarity, with implications for individual success and future prospects under ongoing environmental change. To enhance the ability to trace animal...
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Ecological consequences of seasonal bird migration
Brlík, Vojtěch ; Procházka, Petr (advisor) ; Maggini, Ivan (referee) ; Piersma, Theunis (referee)
Environmental seasonality, and associated fluctuation in resource abundance, affects organisms throughout their life cycles. Periods of resource scarcity can be avoided by seasonal migration, strategy common in animals, including birds. However, the long journeys of migratory birds separate the stages of their annual cycles in space and time, and present them with a variety of challenges. Environmental conditions that migrants experience may have local effects, or may carry over across seasons, and have delayed impacts on individuals and populations. To better understand the interactions between migratory animals and their environment, we integrated individual tracking, environmental measures, and population data within a full annual cycle perspective. We contributed to the understanding that environmental conditions can affect migratory populations both en route and during stationary non-breeding periods, and that their effects can be observed on a continental scale. We also showed, across species and migratory flyways, that stages of the annual cycle are tightly linked during migration, but that these links weaken during prolonged non-breeding stationarity, with implications for individual success and future prospects under ongoing environmental change. To enhance the ability to trace animal...
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The trophic ecology of Sargasso Sea fishes
Horák, Mikuláš ; Horká, Petra (advisor) ; Frouzová, Jaroslava (referee)
This work aims to create a comprehensive overview of current knowledge about trophic relationships within and among fish communities in the ecosystems of the Sargasso Sea and tries to deepen our understanding of the intricate trophic dynamics in these waters and contribute to the broader field of marine ecology. The Sargasso Sea is a unique marine environment characterized by its lack of continental boundaries, with its relative limits defined by major ocean currents. The main objective of this thesis is to consolidate the current research on feeding ecology of fish in the oligotrophic sea waters, with a focus on describing the food webs and species composition of pelagic organisms, along with their interrelationships. To comprehend and illuminate these interactions, various pre-existing data obtained through stable isotope analysis (15 N and 13 C) are employed to determine food web structure and trophic positions. Fluctuations in these values within food webs may provide insights into both natural and anthropogenic influences. Key words: The Sargasso sea, feeding ecology, trophic interactions, food web, stable isotopes
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Metallogeny of selected gold deposits of the Bohemian Massif
Němec, Matěj
The overall text was processed on the bases of two separate articles published recently by the author and collective, and one more article, which is currently submitted for editorial. All the articles in full are attached at the end of this work. First article is trying to decipher the evolution of formation of the Sb-Au deposits Krásná Hora-Milešov, and Příčovy. The second article is in very detail dedicated to transition of gold to aurostibite and formation of Au-Ag-Sb(S) phases at Krásná Hora-Milešov Sb-Au deposit. The third article is looking into genesis of the Voltýřov Au deposit. The Krásná Hora-Milešov and Příčovy deposits are examples of in the Bohemian Massif unique Sb-Au deposits. The deposits consist of vein type mineralization and ore is represented by massive to disseminated stibnite and disseminated gold postdating stibnite. The quartz gangue vein system is developed in Těchnice granodiorite, within robust E-W trending fault zone, and in close association with same oriented repeatedly tectonically rejuvenated lamprophyre dikes. The fluid inclusions (FI) study suggested formation of stibnite at ~250 to ~130 řC and gold at about ~200 to ~130 řC from low salinity aqueous fluids. The bulk of quartz precipitated from the same type of fluid. Disseminated arsenopyrite along with early quartz...
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The influence of evapotranspiration on the groundwater of floodplain forests: Libický luh
Vašková, Hana ; Weiss, Tomáš (advisor) ; Slavík, Martin (referee)
The recherche part of this bachelor thesis deals with evapotranspiration from floodplain forests and its influence on the depth of the groundwater level and mineralization of groundwater. As floodplain forests in the Czech Republic are represented only in smaller fragments, there is a mention of the effect of mineralization on plants. The thesis describes the principle and use of stable isotopes in hydrogeology and the comprehensive characteristics of the area of interest of the experimental part, the Libický luh National Nature Reserve. The experimental part includes the observation of the level, conductivity, temperature, pH, and determination of the isotopic composition of the underground and surface water in Libický luh, where high mineralization of the groundwater was previously detected. The thesis discusses the effect of evapotranspiration on the content of dissolved substances in the water in Libický luh as a possible cause of this phenomenon. It was found that as the temperature rises, the groundwater level drops, and that mineralization remains relatively constant throughout the year. The drop in the groundwater level is evidently caused by intensive evapotranspiration from the floodplain forest during the growing season. However, longer time series of conductivity or hydrochemical...
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Metallogeny of selected gold deposits of the Bohemian Massif
Němec, Matěj ; Zachariáš, Jiří (advisor) ; Slobodník, Marek (referee) ; Sejkora, Jiří (referee)
The overall text was processed on the bases of two separate articles published recently by the author and collective, and one more article, which is currently submitted for editorial. All the articles in full are attached at the end of this work. First article is trying to decipher the evolution of formation of the Sb-Au deposits Krásná Hora-Milešov, and Příčovy. The second article is in very detail dedicated to transition of gold to aurostibite and formation of Au-Ag-Sb(S) phases at Krásná Hora-Milešov Sb-Au deposit. The third article is looking into genesis of the Voltýřov Au deposit. The Krásná Hora-Milešov and Příčovy deposits are examples of in the Bohemian Massif unique Sb-Au deposits. The deposits consist of vein type mineralization and ore is represented by massive to disseminated stibnite and disseminated gold postdating stibnite. The quartz gangue vein system is developed in Těchnice granodiorite, within robust E-W trending fault zone, and in close association with same oriented repeatedly tectonically rejuvenated lamprophyre dikes. The fluid inclusions (FI) study suggested formation of stibnite at ~250 to ~130 řC and gold at about ~200 to ~130 řC from low salinity aqueous fluids. The bulk of quartz precipitated from the same type of fluid. Disseminated arsenopyrite along with early quartz...
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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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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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