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Identification and synchronization of YD period from Eruopaen lake sediments
Skurčáková, Anežka ; Tátosová, Jolana (advisor) ; Sacherová, Veronika (referee)
The bachelor thesis is the rewiew based on paleolimnological determining of Younger Dryas (YD), the final cold episode of the Last Glacial, and its diferent progress in European regions. It contains a describsion and an evaluation of methods of the YD identification (oxygen izotopes 18 O, varve chronology, radiocarbon dating, analysis of diatoms, pollen, chironomids, insect and geochemical and sedimentological analysis). The summary of results of studies from different parts of Europe showed that the first half of the YD in Western Europe was cooler and wetter than the second one. The climate during the YD period had similar temperature profile in Eastern Europe, but humidity had a different trend (the first half was colder and drier while the second one was warmer and wetter. According to the study of lake Švarcenberk in the Czech Republic, the YD had similar phases like in Western Europe. The YD period was synchronous in the most of Europe, its duration was approximately 1,200 years (12 726 - 11 564 years BP). Keywords: Younger Dryas, paleolimnology, oxygen izotopes, radiocarbon dating, varve chronology, climate in Europe
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Diversity, distribution and ecology of epigeous amphipods in the Czech Republic
Hrdinová, Monika ; Sacherová, Veronika (advisor) ; Tátosová, Jolana (referee)
Amphipods (Crustacea, Amphipoda) can be found in fresh and brackish waters and in oceans and seas, several species live in terrestrial habitats. In comparison with other Central European countries there are fewer species of amphipods in the Czech Republic, their number, however, increased over the last decade from 8 to 12 species. Despite that, there is no recent review on ecology and distribution of those species. Presented study is an overview of epigeous species presently occurring in the Czech Republic, their ecology and habitat preferences, deals with changes in distribution areas and factors governing these changes. Based on specific features of species, it can be concluded that for expansion of distribution range a tolerance to extreme temperature peaks is needed, important is also availability of suitable habitats.
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Palaeoecological reconstruction of Komořany Lake in Late Glacial based on diatom analysis
Poštulková, Anna ; Nedbalová, Linda (advisor) ; Tátosová, Jolana (referee)
Diatom analysis of basal part of profile PK-1-L contributes to multi-proxy research of former Lake Komořany. At this part of profile radiocarbon dating (dates sediments into Late Glacial and Early Holocene) and LOI (loss on ignition) had been conducted before, of which results have been utilized to more accurate interpretation of diatom analysis conclusions. Apart from diatom valves, presence of stomatocysts of Chrysophyceae has been observed. Having separated diatom valves from 32 sediment samples in intervals 0,4-0,6 cm, permanent preparates have been created. Concentration of valves in a gramme of dry sediment and relative abundance of diatom taxons in each sample have been investigated using light microscopy. In a half of samples subdominants and rare taxons have been observed separately to eliminate the interference from dominant taxons. Cluster analysis based on relative abundances of diatom taxons have been calculated and on its results have been subsequently determined three diatom accumulation zones (DAZ). Moreover trophic and saprobic indices have been calculated and levels of pH, conductivity and concentration of total phosphorus (TP) have been estimated by transfer functions. Even before beginning of Holocene the major shift in composition of diatom communities have happened, to the...
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Arctic lakes: present zooplankton, subfossil record and past development reconstruction, focused on Svalbard
Sejbalová, Zuzana ; Sacherová, Veronika (advisor) ; Tátosová, Jolana (referee)
Arctic areas have low energy income and therefore harbour very simple food webs. Every environmental change has large and immediate impact. There are many types of lakes in the Arctic, and their sediments accumulate pieces of organisms that inhabited them. Most frequently those are Chironomidae, Diatomeae and Cladocera. My thesis is focused on Cladocera, which have very good subfossil record, most offen carapaces, head shields, postabdomens and ephippia can be found. In palaeolimnological studies these records are used to reconstruct development of environmental factors such as temperature, water level and trophic status. These models can then be used to predict future changes of the environment. My future work will be focused on lake Garmaksla in the central Svalbard and therefore all aspect in presented thesis is focused on Svalbard. Powered by TCPDF (www.tcpdf.org)
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What is the key factor driving the expansion of invasive bentic invertebrates in the czech rivers?
Kolářová, Lucie ; Tátosová, Jolana (advisor) ; Sacherová, Veronika (referee)
The main part of the thesis discusses the occurrence and spreading of non - indigenous species of bentic freshwater invertebrates in the Labe River and it is based on long - term physical, chemical and biological data provided by Povodí Labe, state enterprise. Our results show a decrease in the concentration of nutrients at monitored stretch of the Labe River during the time period between years 2000 and 2011. The relative richness of non - indigenous species in benthic communities was analysed by TCI (Taxonomical Contamination Index), while their relative abundance was analysed by ACI (Abundance Contamination Index). Values of those two indexes increased during the time period between years 1998 and 2012. A detailed analysis is focused on four species - Dikerogammarus villosus, Corbicula fluminea, Jaera istri and Corophium curvispinum. The highest ACI value, as well as the total abundance of D. villosus, C, fluminea and J. istri, has been found at the Velké Březno site. Different values of TCI and ACI indexes and different abundances of specific invasive species can be caused by diverse environmental conditions characterising the studied sites. Significant differences between physical - chemical parameters measured at specific sites has been shown by the Kruskal - Wallis test (α = 0, 05). Only the...
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Seasonal development, long-term changes and effect of extreme events on macrozoobenthos of acidified brooks in headwater catchments of Litavka, the Brdy Mountains
Beneš, Filip ; Tátosová, Jolana (advisor) ; Peltanová, Jana (referee)
This Master thesis was focused on seasonal development of macrozoobenthos for season 2009-2010, its long-term changes and effects of extreme events on acidified brooks in headwater catchments of the Litavka river in the Brdy Mountains (the Czech Republic). The extreme events are considered: drought, floods and deforestation. Changes in composition of macrozoobenthos were compared with the previous research, which was provided there for season 1999-2000. Headwater catchment of the Litavka river consist of two streams: strongly acidified Litavka-krmelec (LK) and slightly acidified Litavka-hlavní (LH), which is taken as a reference stream. Measured pH levels of LK were in range of 4,00-4,22 (with median 4,10) and concentration of reactive aluminium (R-Al) were in range of 1381-2187 µg.L-1 (with median 1692 µg.L-1 ). Measured pH levels of LH were in range of 4,74-6,22 (with median 5,62) and concentration of reactive aluminium (R-Al) were in range of 8-400 µg.L-1 (with median 33 µg.L-1 ). Concentrations of R-Al are observed due to toxic forms of Al3+ ions on aquatic organisms. The significant differences in composition of macrozoobenthos were also observed. On strongly acidified study site LK were not present acidosensitive groups, such as mayflies, molluscs and some species of caddisflies. All of these...
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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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Influence of reservoirs on communities of river flow
Lavičková, Šárka ; Černý, Martin (advisor) ; Tátosová, Jolana (referee)
Construction of dams significantly affects the chemical, biological and physical properties of the flow below the dam. These changes include a decrease in the numbers of individuals one or more species, the complete disappearance of species, or the introduction of non-native species. Disruption of natural water flow also applies to animals, who have only one stage of their life (usually reproduction) connected with the aquatic environment, although they are not permanent residents. Also necessitate significant changes in the life cycles of native plants and animals near the regulated river. Basic principles of behavior impounded flow describes the concept of serial discontinuity, which assumes that the construction of the dam will break river continuum, which then causes changes in river communities. Undergoing significant change such as flow regime in the river below the dam, the most striking changes are caused by the flow hydroelectric power stations. In addition, a temperature change in the flow decreases turbidity and often the availability of nutrients, because the location of the dam with the usual outlets (high or medium) acts as a trap sedimentary particles of organic and inorganic origin. It is important but also the contact area of the river, for example, reducing the zaplavovaného...
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An acidification of fresh waters is not over
Beneš, Filip ; Tátosová, Jolana (advisor) ; Hardekopf, David (referee)
Acidification of freshwaters is a problem of many areas over the northern hemisphere from the half of the 20th century. It has been caused by industrial factories discharging emissions of sulfur and nitrogen oxides, from which originate acids by the photochemical reactions in the atmosphere. Acidic atmospheric deposition has caused disappearance of fish and the most aquatic organisms in streams and lakes. Acidic atmospheric deposition has also washed up not only the buffering basic cations (Ca2+ , Mg2+ , Na+ , K+ ), but also toxic aluminium (Al3+ ) ions from soils into the freshwaters. The maximum levels of emissions of sulfur and nitrogen oxides were observed in 1980s and since that time the emissions of sulfur and nitrogen oxides significantly dropped down. However, the recovery from acidification is not as fast as it could be expected. It is impeding by several processes. One of them is hysteresis or saturation of soils by sulfur and nitrogen, which are slowly washing up into the freshwaters in forms of sulfates and nitrates now. Another process is the oligotrophication of lakes, when the important nutrient - phosphorus - is precipitating by aluminium. There is the lack of food for organisms after that. Another processes slowing down the recovery from acidification could be bad forest management...
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