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Holocene climate changes in the High Arctic
Prochová, Dominika ; Vondrák, Daniel (advisor) ; Roman, Matěj (referee)
Climatic changes are nowadays frequently discussed subject in the scientific, political and public sphere. For better understanding of their causes, development and possible impacts is one of the basic prerequisites for investigating such anomalies, that have taken place in the past. In natural archives, it is possible to find records not only about their parameters but also about the mentioned impacts - ecosystem changes, earth surface's geomorfological transformartions or the impact on human society. The most studied period of geological time is Holocene. It is about the most recent period and we currently live in its third stage. Thankfully, due to relatively sufficient knowledge of its climatic anomalies we are able to study the climate's contribution with enough complexity to valorize the currently much observed global warming, witch is often connected to human activity. The Arctic is probably the most sensitive place to climate changes on the planet. The warming, that is currently observed around the globe, is there noticeably higher - by the end of the 20th century, the average annual temperature increased twice as fast. The aim of this thesis is, in the form of literary research, to describe and examinatie the climate development in high Arctic areas, potencially the most sensitive...
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Quaternary molluscs of Blanský les
Menšík, Jakub ; Juřičková, Lucie (advisor) ; Pokorný, Petr (referee)
Rich mollusc assemblages preserved in two profiles of fossiliferous sediment in the Blanský les area, provided the evidence about the Late Glacial and Holocene in this region, which is one of the most faunistically known areas of Central Europe. Findings of Quaternary faunas are very rare in Southern Bohemia, so these two soil profiles near Český Krumlov are so important for understanding the postglacial succession of Central Europe. The fossil mollusc assemblages showed an early appearance of forest species, which dominated both sites from the Boreal till Subboreal. Forest development in the Holocene Climatic Optimum reached a maximum, due to the absence of Neolithic man. Steppe species almost completely disappeared during this period. The development of the Young Holocene was linked to a decrease of the forest on the first site and the deforestation of the second site, due to a combination of a humidity decrease and human impact. In addition, some southern elements involved in the postglacial colonization of Central Europe, were found there. A few of them were found in a much older deposit than expected.
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Correlation of abiotic proxies in Holocene lacustrine sediments of Peri-Atlantic Arctic
Roman, Matěj ; Nývlt, Daniel (advisor) ; Sedláček, Jan (referee)
The peri-Atlantic Arctic, one of the most sensitive components of the Earth climate system, experienced pronounced climatic fluctuations during the Holocene. Several external forcings were considered responsible for these variations, including decline of insolation on the Northern Hemisphere, changes in distribution of land ice mass, explosive volcanism, or changes in atmospheric and oceanic circulation. In order to explore the driving mechanisms of the peri-Atlantic Arctic environmental variability, three sites located in different parts of the region were selected for palaeoenvironmental reconstructions with focus on extracting the climatic information. With this intention, sedimentary cores from i) Lake Garmaksla, Central Svalbard, ii) Jarfjorden, northeastern Norway, and iii) Kobbefjord area, southwestern Greenland, were retrieved and subjected to multi-proxy investigation. The absolute chronostratigraphic framework was established by comprehensive radiocarbon (14 C) and short-lived radioisotopes (210 Pb, 137 Cs) dating. Further analyses include measurements of magnetic susceptibility, grain size distribution, element composition by means of X-ray fluorescence (XRF), and elements bound to organic matter, i.e. organic carbon, nitrogen, sulphur and biogenic silica. The relationships between the...
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Changes in vegetation of Karpaty since glacial maximum - identificaition of main trends accesibility of data and gap in knowledge
Beranová, Jana ; Kuneš, Petr (advisor) ; Jamrichová, Eva (referee)
The Carpathian Mountains are great range in Europe. This rewiew is target to identify main evolution trends of vegetation i Carptahian Mountatins. I studied materials whitch was concetrate to pollen analysis and malacological finds. Based on this materials I found that in the stadial dryas periods there were climatic conditions for small forrest islands mainly formed from genus Pinus and Larix. In the interstadial periods the different climatic conditions permit forrest propagation and became denser. Transitions from pleistocen to holocen was nearly similar to the situation in interstadial period. But later in the holocene the density of the forest is growing more and dominant of late glacial forest was replaced mainly by the spurce. Population of plants that survive the glacial in the Carpathian mountain growing as same as and new species that survived glacial in warmer localities. In the subatlantic and especially in the few last decade the human efect is important and can be found in the pollen analysis. On the research of plant evolution in Carpathian mountain is necessary to continue, mainly on identification and analysis new localities. This large area is unequaly covered by localities.
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Holocene succession of European mollusc fauna
Menšík, Jakub ; Juřičková, Lucie (advisor) ; Moutelíková, Jitka (referee)
Abstact Study of Quaternary mollusc succession has a long-term tradition in Europe. It is because mollusc shells used to be commonly and numerously preserved in calcareous quaternary sediments of various origins. Since the second half of the last century, these successions are used as proxy data in paleoecological studies. Based on knowledge of recent ecology and composition of Quaternary assemblages, mollusc species can be divided into ten ecologicalgroups used for a reconstruction of paleoenvironment. The ecological group of strictly forest species is crucial for central European fauna. . This group indicates the canopy forest with its characteristic microclimatic conditions, which represents zonal ecosystem of Central Europe. Indication value of molluscs for canopy forest habitats used to be in question in other parts of Europe except of Central Europe. That is why this theses reviewed available information on mollusc successions of strictly forest species across Europe based on a maps of known strictly forest species occurrences during the Late Glacial and Holocene. This visualization indicates the general movement patterns of strictly forest mollusc fauna from the Late Glacial to present. The main methodical problems in the study of Holocene mollusc succession are also commented.
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Remnant of forest at the transition from Late Glacial period to Holocene: dendroecological and palaeobotanical reconstruction
Moravcová, Alice ; Šamonil, Pavel (advisor) ; Rybníček, Michal (referee)
The remains from a sub-fossil pine forest burried in layers of peat deposits at the northern edge of the CHKO Křivoklátsko in the Central Bohemia is completely unique findings for the area of the Czech Republic. It offers new opportunities for palaeoenvironmental reconstruction and related climate changes during the Late Glacial and early Holocene epoch. The methods of dendrochronology and radiocarbon dating were used to date subfossil trees. The results of radiocarbon dating determined the existence of the forest in the period approximately 12,000 to 10,300 cal yr BP. The dendrochronological analyses revealed two continuous floating chronologies. The chronology RD4, which is long 200 years, originates from the Younger Dryas. The chronology RD6, 300 years long, originates from the Preboreal. The growth dynamics of the forest were reconstructed on the basis of the tree- ring analysis. Hydrological regime has been identified as a major disturbancy factor that influenced the growth of trees. This has been evident from synchronous phase depressions in the growth of synchronized tree-ring series. The high water table was the main cause of their extinction. This was in concordance with the results of macrofossils analyses. The effect of hydrological regime was largely influenced by microsite differences...
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Long-term dynamics of Ledum palustre - testing the distribution model with paleoecological data
Radoměřský, Tomáš ; Kuneš, Petr (advisor) ; Petřík, Petr (referee)
On the territory of the Czech Switzerland National Park took place during the Holocene significant changes in vegetation cover to the form is most enrolled medium Holocene climatic optimum when broadleaf deciduous forests expanded into Central Europe. These transformations are caused by climatic changes. However, it started the process of soil acidification to this day that caused the other variations of the vegetation composition, even the extinction a variety of species especially in sandstone areas. In addition, in the last few centuries the human impact is graduating, which more or less of the original forests changes due to agricultural and economic reasons to breed-specific and the same-aged plantations which supports the already declining species diversity and relative abundance of the undergrowth species. This work focuses on a single species, evergreen undergrowth shrub Ledum palustre which is characterized by strong demands on its habitat and indicates the specific habitat type. It grows on the upper north-facing edges of rocks with plenty of light and humidity. At these locations stores organic material thanks the favourable hydrology. This makes possible to study the use of pollen and macroremains the paleoecology of the species. On the basis of recent occurrences and the relationships...
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Quaternary insects and their significance for zoogeography, paleoclimatology and paleoecology
Moudrý, Jakub ; Prokop, Jakub (advisor) ; Říhová, Dagmar (referee)
The present thesis is a review of available published data on Quaternary insects. Research focused on Quaternary insects has been so far overlooked by the Czech scientists, even though there is potential to provide additional data for complex reconstruction of Quaternary deposits. Insect faunas allow to trace the dynamic development of areas across continents and serve for example as proof of migration routes. It is especially true for the Pleistocene, well known for prominent climatic oscillations. Thus, the insect species served as climatic indicators allowing estimations of average temperatures by application of the MCR method. Finally, these faunal changes reflect dynamic development of palaeoenvironments. The fact that the subfossil taxa correspond to the recent species allows broader reconstruction of the Quaternary deposits.
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Dental phenotype variation in voles during the present glacial cycle
Putalová, Tereza ; Horáček, Ivan (advisor) ; Kuneš, Petr (referee)
The phenotype dynamics of arvicolid rodents during the terminal stages of the Vistualian glacial and the earliest Holocene was investigated with aid of a detailed morphometric analyses of extensive dental material from three sedimentary series of that age. The particular attention was paid to the record from a section in Býčí skála cave, Moravian karst, which demonstrated details of the Pleistocene/Holocene transition (12.4-8.4 ky BP) with extraordinary resolution. It revealed that dramatic rearrangements in community structure were accompanied by significant rearrangements of the phenotype dynamics in all arvicolid species. Despite some trends specific for particular species, some common features were identified as well. One of them was a rapid turnover in phenotype structure by the end of Younger Dryas, at time of the Preboreal event. (11.7-11 ky BP), the other was associated with the extensive shifts in community structure and habitat diversity at terminal stage of the Preboreal (9.7-9.3 ky). The core arvicolid species of Preboreal communities, Clethrionomys glareolus, Microtus arvalis, M.agrestis and Arvicola terrestris, exhibited repeated fluctuations during that stage (ll-9,3 ky BP) both in abundance and phenotype characteristics, supposedly related to serial invasion events during that time....
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