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Climate and settlement dynamics based on comparison of dendroclimatic and archaeological data of South Bohemian holocene.
VOBEJDA, Libor
The environment is influenced by the ever changing system of interacting forces. Changes in the climate are amongst many crucial factors that determine life conditions on Earth. All organisms have to cope with the environmental changes and humans are no exception. This thesis is focused on description of climate changes during the Holocene geological epoch. The climate is delineated based on proxy datasets. South Bohemian proxy data, mainly tree ring chronology, are used as primary sources for the reconstruction of past climate. These proxy datasets are complemented by various climatic reconstructions covering the area of central Europe. In order to assess the connection of past human societies to climate, a comparison between climate and settlement proxies is conducted. As an example of the settlement proxies we can list relative population density and location of dwellings. Target populations are agricultural prehistoric and historic societies.
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Citlivost letokruhových řad borovice kleče a smrku ztepilého ke klimatickým parametrům horní hranice lesa
Mikušková, Jana
Trees growing on the treeline can serve as a sensitive indicator of changes in climatic parameters associated with ongoing climate change. Understanding differences between trees and shrubs growing in this ecotone is a key for understanding the functioning of the treeline. Therefore, the submitted thesis deals with the study climate diameter-growth responseof Norway spruce and Dwarf pine. Samples from Norway spruce and Dwarf pine were collected at the localities at treeline in the National Nature Reserve Praděd in the Jeseníky PLA. Indexed chronologies were developed for Norway spruce and Dwarf pine using various detrending methods of raw tree ring series (Spline, Negative Exponential, Ar, Mean, Friedman). For subsequent dendroclimatological analysis, I used the chronology with their tree ring series were detrended using Spline. Subsequently, correlations of the indexed tree-rings width with monthly climatic variables (average temperature, precipitation total, PDSI – Palmer drough severity index) were calculated. These correlations were investigated both for the entire chronology period and separately for the sliding time sequences within the chronology. It was found that the radial growth of Norway spruce is influenced mainly by temperature in the growing season (May to July) and in November in the year preceding the creation of the tree-ring. In the case of monthly precipitation, their positive correlation with radial growth was recorded only in March and no significant correlations were noted for PDSI. The growth of Dwarf pine is influenced by the temperature at the beginning of the growing season (June) and in October in the year preceding the growth of the tree-ring. Monthly precipitation negatively affects radial growth in October in the year preceding the growth of the tree-ring and no significant correlations were noted for PDSI. The results correspond to the view that the most important factor for the growth of trees at the treeline is temperature, that is not so important for shrubs. The monthly precipitation sums and drought index are not limiting for woody plants of this ecotone.
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Development and interpretation of site tree-ring chronology of Pinus sylvestris
Mašek, Jiří ; Treml, Václav (advisor) ; Šefrna, Luděk (referee)
The presented bachelor thesis deals with the study of climatic factors that influence the growth of the pine (Pinus sylvestris) in the locality near Rabštejn nad Střelou. The primary objective was to determine the limiting factors of tree growth and to perform dendroclimatic reconstruction. For this purpose, samples were taken at the site and local chronologies were created using various standardization methods. Using the correlation coefficients, limiting growth factors were determined, and reconstruction by regression and scaling was performed based on the highest correlation. The results showed a strong relationship of rings width to rainfall and humidity conditions, especially in the summer months and in various seasons from April to August. Most of the chronologies also showed the positive influence of February temperatures. Observed signature rings in many cases are well responsive to various climatic anomalies. For the most correlated variable, dendroclimatic reconstruction was calculated for the period 1850 - 2016 when the chronology was reliable. The reconstructed average rainfall corresponds well with the Klementinum climate line and other rainfall reconstructions.
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Selected approaches of climate-growth relationship determination of trees
Pekař, Ondřej ; Treml, Václav (advisor) ; Ponocná, Tereza (referee)
Presented bachelor thesis describes the use of tree-ring widths in dendroclimatology and main approaches of climate variables reconstruction. It reviews the basics about climate influence on tree- ring fromation and extraction of climate signal from tree-rings. Main standartization methods were used to develop 26 standard and residual chronologies from adjusted and not adjusted tree-ring series coming from high-elevation Norway sporuce stands. Chronologies were compared in terms of correlation with summer temperatures. The best correlated temperature variable were the June-July temperatures both for standard and residual chronologies. Tree-ring width chronologies were scaled to observed June-July temperatures. Based on comparison of scaled and real June-July temperatures, negative exponential function and RCS method appear to be the most suitable to preserve both high and low frequency climate signal. Key words: Dendroclimatology, tree-rings chronology, standardization, climate reconstruction
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Sensitivity of Scotch pine ring-width chronologies to climatic variables
Lehečková, Eliška ; Treml, Václav (advisor) ; Vejpustková, Monika (referee)
Presented master's thesis deals with the climate sensitivity of radial growth of Scots Pine (Pinus sylvestris) growing in the Protected Landscape Area Kokořínsko. The principal aim was to find out whether there are differences in the climate-growth response of pines growing on dry and mesic sites. To cope with that question tree ring cores were collected from stands on dry sandstones plateau and from stands near valley bottom with better water supply. Residual chronologies were developed and climatic factors limiting growth were identified using partial correlation analysis. The results show that pines on rocky sites respond positively to high precipitation during the vegetation season whereas trees on wetter sites react positively to high temperatures. In most study stands high February temperatures positively affect radial growth. Moving partial correlations analysis showed that the strongest responses to month climatic variables were stable over the studied period 1902 - 2009. Pointer years were determined and compared with precipitation and temperature anomalies in the corresponding pointer year, furthermore the effect of climate on number of trees with growth anomaly was studied using partial correlations analysis. Results of these analyses were in compliance with the previous findings. In...
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