|
|
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...
|
|
|
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.
|
|
|
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....
|
|
|
Holocene history of Arctic lakes
Roman, Matěj ; Nývlt, Daniel (advisor) ; Kavan, Jan (referee)
Holocene history of Arctic lakes Abstract Palaeolimnology in the Arctic has achieved a considerable progress in the last decades. The Arctic has changed markedly since the Last Glacial and glacier retreats caused formation of a great number of diverse lake types. Lakes of glacial origin, thermokarst lakes, fluvial lakes and lakes on raised beaches occur most often here. Palaeolimnological methods applied to the high latitude areas are used for the study of the history of individual lakes. Methods of correlation of sedimentary cores and basic interpretation of proxy records such as magnetic susceptibility, diatom biostratigraphy and content of carbon and sulphur were applied on sediments of Garmaksla Lake, Svalbard Archipelago. Climatic and ecological shifts including the Little Ice Age termination and recent warming were registered in proxy values. Keywords: lakes, palaeolimnology, palaeoclimatology, environmental changes, Holocene, Arctic
|
|
|
Diatoms of Quaternary Sediments from the Lake Komorany
Poštulková, Anna ; Rajdlová, Hana (advisor) ; Houfková, Petra (referee)
Diatoms are unicellular phototrophic organisms, whose siliceous frustules preserved in sediment have broad palaeolimnological application. Sediments of former Komořany Lake count among the richest Czech sediments in quaternary diatoms. This already destroyed locality is examinated in search and practical part of work. The search part contains characterization of diatoms and locality Komořany Lake. Diatoms are described in paleontological point of view, that is why the main attention is payed to morfology of frustule, their ecology and application in geological sciences. However, for complete image of this various group, the new pieces of knowledge about their taxonomy or evolution are not overlooked. The root of the work is summarization of accessible literature about Komořany Lake with special attention to research of diatoms. In practical part diatom valves were isolated from samples of sediment from profile PK-1-W, 18 long-lived sections were prepared and 6 of them were used for taxonomical determination. The 47 taxons of diatoms were found, 7 of them had not been included in work of Řeháková (1986). The synonymy of taxons are created in comparison with results of Řeháková (1986). From taken pictures are created 6 taxonomical plates. Key words: diatoms, Bacillariophyceae, Komořany Lake,...
|
|
|
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 Carpathian Mountaitns. 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 and geographically complicated need informations from new localities.
|
|
|
The Quaternary Paleoecological Analysis of the Soos National Nature Reserve
Rajdlová, Hana ; Holcová, Katarína (advisor) ; Novák, Jan (referee)
The Quaternary Paleoecological Analysis of the Soos National Nature Reserve The aim of this proposed diploma thesis is to describe the structure of diatom communities in the diatomite deposits of the Soos National Nature Reserve and compare the finding of this thesis with those of older publications. Another aim was to reconstruct the history of the basin trough with the outputs of diatom analysis accomplished in the 3,4 m long sediment profile. The similarity of diatom communites in individual diatomite types was also tested. Key words: subfossil diatoms, Soos National Nature Reserve, paleolimnology, Late Glacial, Holocene
|
|
|
Forest evolution in Central Europe during the Holocene periode
Švábová, Barbora ; Šefrna, Luděk (advisor) ; Matějček, Tomáš (referee)
The work deals with the forest as an ecosystem where relationships take place, which are influenced by abiotic and biotic factors. Great attention is paid to the climate, which affects not only the distribution of biomes. Its constant changes have an impact on the species composition of forests and human society. By the effects of the climate, the Holocene period was divided into sub-stages. Man also played a significant role in the conversion of the central Europe forest and changes it even now. That is why this work devotes a considerable part of it to this influence. Great changes of the forest began with the emergence of agriculture, which was the first impulse for the beginning of deforestation. Examined are the ways of prehistoric and modern economy. With the loss of trees came an idea of protecting the forests. As an example of possible further effect on the forest, the influence of some pathogens is presented.
|
|
|
Postglacial vegetation history of local phenomena in western Bohemia
Švarcová, Markéta Gabriela ; Kuneš, Petr (advisor) ; Kozáková, Radka (referee)
In the sense of postglacial vegetation development, western Bohemia represents one of the least studied regions in the Czech Republic. This area, however, represents a supposed migration route of trees towards northern Europe during the Holocene. The most appropriate area for testing of such proposal might be western Sudetes with Slavkovský les protected landscape area in the Karlovy Vary region. Postglacial vegetation history was studied on the basis of two sedimentary profiles - from the fen bog near Číhanské prameny springs and from the vicinity of Mnichovské hadce serpentines from the nature reserve Mokřady pod Vlčkem. Percentual as well as influx diagrams were constructed on the basis of results of standard pollen analysis. Comparison of these results with the data from other suitable profiles enabled reconstruction of migration history of main tree taxa. The Číhaná profile reflects the period from the Older Dryas up to the Atlantic. The oldest Holocene forest was formed by the dominant Pinus, while Corylus was joining already in the Preboreal. Quercetum mixtum folowed in the begining of the Boreal and spruce quickly gained dominance in the Atlantic. The sedimentation process was probably finished due to rapid accumulation of sediments followed by spontaneous drainage ending with spruce and alder...
|
|
|
History of vegetational development in the Cheb basin from sedimentary record of the SOOS National Nature Reserve
Suda, Tomáš ; Kuneš, Petr (advisor) ; Bešta, Tomáš (referee)
Vegetation development in the Cheb basin ( W Czech Republic) recorded in the sediments of the SOOS ational ature Reserve This thesis focuses on palaeoecological research of quaternary sediments in the Soos National Nature Reserve (Cheb basin, NW Czech Republic). Quaternary history of this locality is poorly known, despite it is a valuable and protected area with high natural qualities. The Soos basin is also known for its unique geological record, which is expected to cover information on landscape dynamics at least during the Holocene. A lake existed in the Soos basin enabling accumulation of diatomite and peat sediments of a broad palaeoecological potential. Records were analysed with method of pollen analysis and were dated using 14C. The results of this study bring information about vegetation development in the area of Cheb basin as well as development of lake ecosystem. It also gives a new insight on lake's origin and its age. The accumulation of peat sediments started in the Preboreal period and was continuous at least until the Atlantic following with a hiatus, therefore further detection of vegetation development is impossible. The beginning of diatomite accumulation, as well as the existence of the lake goes back to the Bølling interstadial, according to radiocarbon dating. However, this...
|
guest ::
