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Role of microbes in the decomposition in headwater streams.
Kociánová, Petra ; Kopalová, Kateřina (advisor) ; Tátosová, Jolana (referee)
The decomposition of organic matter in headwater streams is a key process in stream ecology and an important component of the global carbon cycle. Decomposition rates depend on both abiotic and biotic factors, the former including temperature, discharge, and nutrient chemistry, and the latter including stream community structure and activity, trophic interactions, biodiversity, and productivity. Of the stream community, microbial decomposers play a particularly important role in decomposition by chemically degrading compounds and transferring nutrients and energy to higher trophic levels. These processes are prone to change due to current and future global warming which will affect both decomposer communities and associated decomposition rates. This thesis provides a short overview of the main factors that control stream decomposition rates, including biological factors like microbial activity, abiotic factors such as water temperature and nutrient availability, and how these factors may be altered in the future under a warmer climate. Specifically, I predict that climate change will increase microbial activity and decomposition in headwater streams due to increased water temperatures, changes in surrounding vegetation, and shifts in the hydrological regime due to global warming. .
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n-Alkanes and GDGTs biomarkers in lake sediments as a tool for quantitative paleoclimate reconstruction
Machová, Tereza ; Tátosová, Jolana (advisor) ; Jandová, Kateřina (referee)
The review is divided into two major sub-sections, the first focusing on n-alkanes and the second on GDGTs. Considering n-alkanes, the carbon chain length and the predominant evenness or oddness are of particular importance to identify the source organism. However, the high species and interspecies variability in chain length associated with environmental conditions or the differences in the amount of n-alkyl lipid production are problematic. Since n-alkanes are composed of carbons and hydrogens, they can also be studied based on their isotopic composition. Plants discriminate against heavier isotopes of carbon and hydrogen during the formation of organic molecules, resulting in the production of more depleted compounds. Using δ13 C, we can determine the water availability over time or the exchange between C3 or C4 vegetation; applicability is limited by the latitude of the site or bacterial production of n alkenes. δ2 H of C17 alkane can reveal the evapotranspiration of a lake and/or the δ2 H values of lake water, nevertheless, we need sufficient concentrations of the n-alkane in question, and be sure the source of the hydrogen in the lake water hasn't been affected in the past. GDGTs use to be analyzed primarily by their structure, which may change with changes in ambient temperature, i.e. GDGTSs...
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Interpretation of carbon stable isotope data from lake sediment archives
Lánová, Zuzana ; Tátosová, Jolana (advisor) ; Jandová, Kateřina (referee)
Lake sediments consist of terrestric plant matter, lacustrine plancton primary production and microbial lake biomass. All of these organism groups discriminate during C-substate fixation and/or its further assimilation heavier and more stable 13 C carbon at a certain ratio, which is reflected by 13 C concentration in their biomass and consequently in sediments. The reason of discrimination at these enzymatically controlled biochemical reactions lies at kinetic fractionation controlled by binding energies of chemical substances. Isotopic signature contained in organic matter of lake sediments can be influenced by photosyntesis intensity, formation of anoxic zone allowing methanogenic a methanotrophic bacteries activity, lake trophic state or hydrologic isolation (long periods of drought). Keywords: Paleolimnology, carbon isotopes, discrimination processes, lake sediments
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Cathegorization of small ponds in the PLA Broumovsko
Mňuková, Veronika ; Tátosová, Jolana (advisor) ; Černý, Martin (referee)
This bachelor thesis is about small artificial ponds and their value in landscape. It characterizes their basic features, colonization rate, role the play in maintaining biodiversity and their significance for nature conservation. In the practical part of my thesis, I am focusing on small ponds in CHKO Broumovsko and analyzing them in context with their possible colonization. The main aspects that I take into consideration, are their spatial distribution, age, biotopes in which they are situated, their relation to streams and terrain in their surroundings. The result of my work is cathegorization of the ponds, which reflects these characteristics and defines groups of potentially similar and different ponds. Hypothesis that emerged from this cathegorization will be further used in biodiversity research within my subsequent master thesis. Key words: small ponds, biodiversity, colonization, mapping, cathegorization
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Chironomid fauna of acidified mountain waters
Malá, Martina ; Tátosová, Jolana (advisor) ; Vondrák, Daniel (referee)
Acidification of freshwater ecosystems peaked in 1980. There were overall changes in the chemistry of surface waters. As a result, some fish and sensitive species of zooplakton and zoobenthos disappeared. After the peak, emissions of major pollutants (SO2, NOX a NH3) declined significantly, which started the process of recovery from acidification. Nevertheless, biological recovery proceeds very slowly and it is not clear whether it is a completely reversible process. Chironomids serve as a very useful tool to assess acidification and recovery processes, mainly due to their toletance and also sensitivity of species to low pH, concentration of dissolved oxygen, nutrient content and adaptability to changes in food supply. Chironomids have in general high adaptability of species to harsh conditions. Food supply and concentration of dissolved oxygen are likely the main factors which influence the assemblages of chironomids in freshwater ecosystems. Chironomids are suitable for use in surface water research and biomonitoring due to their world-wide distribution, high species diversity and density. In comparison to other families of zoobenthos there is far less studies of chironomid assemblages, because of demanding determination. The CPET method, which uses collection of pupal exuviae, has great potential...
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Invasive water invertebrates in Czech Republic
Kolářová, Lucie ; Tátosová, Jolana (advisor) ; Dočkalová, Kateřina (referee)
An introduction of invasive species is considered to be one of the most actual problems of these days and is also related with water environment and water invertebrates. Occurences of many non-native species has been recorded in waters of the Czech Republic and these species can be divided into two groups. Species of the first group are invasive alien species - their ecological patterns (e.g. high growing rates, high reproductive capacity or ability to transfer exotic diseases) make their spreading more successful. North-American crayfish species (Orconectes limosus and Pacifastacus leniusculus), Dreissena polymorpha or Dikerogammarus villosus are the typical representatives of this group. The spreading of these species is very remarkable, since their introduction causes many harmful effects and has negative impacts on native fauna. However, the appearance of other group of water invertebrates has been found in our waters. These are also non-indigenous species, but their spreading is very inconspicuous - they do not reach high population densities and their invasion does not cause negative impacts on native fauna and ecosystems. The evidence of these harmless invasive species has been recorded thanks to the monitoring programs and we possibly wouldn't know about them without this monitoring. The...
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Possibilities to restore seminatiral meadows in post industrial sites.
Kolářová, Petra ; Frouz, Jan (advisor) ; Tátosová, Jolana (referee)
The post-industrial sites (brownfields) are sites which were devastated and abandoned by industrial production (generation areas, dumping grounds, mining areas…), but buildings and paved areas abandoned by agricultural production, too. On the other hand on these very disturbed places, primary succession, may leads to recovery of valuable ecosystems. It shows the potential of these areas for the restoration of valuable near natural ecosystems. One of the possibilities how to use these areas could became establishing species rich meadows rich, which could return to the meadow ecosystem his original function. They could benefit from oligotrophic status, at least some of these sites, too. The aim of this work is to summarize the information about factors which influence structure and diversity of meadows, their restoration and assess chance post-industrial sites utilization for the recovery of species rich meadows. Finally results of experiment about restoration of species-rich meadow ecosystems on mine spoil dumps in the surrounding of Sokolov are represented.
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Sediments of Bohemian Forest lakes and their use in paleoenvironmental research
Vondrák, Daniel ; Tátosová, Jolana (advisor) ; Hruška, Jakub (referee) ; Kyška Pipík, Radovan (referee)
Sediments of Bohemian Forest lakes are important natural archives. Their sedimentary record covers postglacial history of the lakes as well as history of natural processes in a wider region. It also documents local settlements and changes in landscape management. The lake sediments have attracted the interest of the scientific community since the end of the 19th century. Despite of the fact that modern paleolimnological and paleoecological investigations were already performed in the second half of the 20th century in the Bohemian Forest Mts., the great potential of the lake sediments was not fully utilized in scientific research so far. The ultimate objective of this thesis is to deepen knowledge of these natural archives and support their utilization in future studies. Several specific objectives have been set to achieve the ultimate objective: i) to compare age of the Bohemian Forest lake sediments with the recent knowledge of local deglaciation at the end of the last ice age, ii) to integrate chronostratigraphic marker horizons as one of the tools of Late Glacial sediment dating, iii) to assess the role of bioerosion in chitinous subfossil freshwater invertebrate remains on the record representativeness, and iv) to prove the presumed dystrophic nature of the lakes during the Holocene using...
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