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Emerging Trends in Dendrochronology
Horáček, Tomáš ; Neuwirthová, Ludmila (referee) ; Mikulka, Jan (advisor)
Tato práce se zabývá popisem současných a experimentálních metod odběru vzorků pomocí presslerova nebozezu, výřezů z kmene, fotografie, rentgenu, počítačové tomografie a magnetické rezonance na poli dendrochronologického výzkumu. V práci jsou rozebírány destruktivní a nedesktruktivní metody odběru vzorků. Je také kladen důraz na původ vzorků: zdali je možno využít destruktivní metody nebo zdali je to nemožné jako v případě vzácných archeologických objektů. Dále popisuje standardní optometrickou metody a další experimentální metody fungujicí na principu kontranstního zpracování obrazu za účelem rozeznání letokruhů. V práci jsou také popsány různé druhy metod softwarového zpracovnání kde jako vstup slouží buď série dat nebo obraz letokruhů. Další rozdíly tvoří vymezené spektrum uvedených prací, některé práce se zaměřují na zpracování obrazu od píky tedy od pořízené fotografie až po hotové datovaní, některé však zajímá pouze úzký sektor dendrochronologie jako jsou například vady či špatně rozeznatelné letokruhy.
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Sestavení historické části regionální dubové standardní chronologie pro oblast jihozápadní Ukrajiny
Formánek, Šimon
Due to the high number of preserved wooden churches and bell towers in the southwest of Ukraine, it is possible to study their architecture and history. By the use of dendrochronological dating, we can determine with annual accuracy their construction or reconstruction year, which can be compared with the information available in historical literary sources. The aim of this thesis was to use dendrochronological analysis to determine the age of individual sacral buildings and to create a local standard oak chronology. Dendrochronological dating took place on a total of 11 churches and bell towers in the region of southwestern Ukraine. 167 samples were collected for analysis using Pressler borer. 41 oak and 5 fir samples were successfully dated. Oak wood had the highest representation among individual samples – 144. The wood of fir, spruce, poplar, ash and birch was present to a lesser extent. The oldest wooden element that has been reliably dated is from the Church of St. Nicholas in Serednia Vodiane, dating from 1591–1599. On the other hand, the youngest dated structural elements dating back to 1973/1974 are from the Church of St. Michael the Archangel in Uzhgorod. Other wooden churches and bell towers date back to the period between the 16th and the turn of the 17th and 18th centuries. Based on the successfully dated tree-ring series it was possible to create a local oak standard chronology covering the years 1366–1805 and 1890–1972. Dendrochronological dating helped to clarify the structural and historical development of wooden sacral buildings in the southwest of Ukraine and to provide information that is often missing in literary historical sources. The newly developed standard oak chronology will be able to serve as one of the cornerstones of a new oak standard chronology for the region of southwestern Ukraine.
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Tree-ring chronologies of Norway-spruce on west-east longitudinal gradient in the mountain ranges of central Europe
Ponocná, Tereza ; Treml, Václav (advisor) ; Kolář, Tomáš (referee) ; Vejpustková, Monika (referee)
The Earth's climate system has recently experienced substantial warming which likely impacts temperature-limited communities close to their distribution margins. The alpine treeline ecotone represents upper distributional limit of montane/subalpine forests. This biogeographic boundary relies mainly on decreasing temperature with increasing elevation. Surprisingly the response of treeline ecotone to ongoing warming has varied a lot and the reasons of this variability are poorly understood. The aim of this dissertation thesis is the assessment of growth trends and tree ring response of Norway spruce (Picea abies[L.] Karst.) to climatic oscillations at treelines and montane forests of East-Central Europe. This dissertation deals with both inter-regional and intra-regional (aspect, elevation) variability of tree growth. The presented results are based on an extensive data set of growth curves for almost 1400 trees. All study sites revealed close relationship between tree ring widths and growing season temperatures as well as the temperatures of October preceding to ring formation season. The main site-dependent differences in growth trends and temperature responses were attributed to elevation, the effect of aspect was relatively less significant. At treelines between the Krkonoše Mts. and Nízké Tatry...
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Historical records of Hg emissions in the Prague city using dendrochronology
Miller, Zbyněk ; Dočkalová, Kateřina (advisor) ; Mihaljevič, Martin (referee)
The primary aim of this work was to estimate whether tree rings of Norway spruce (Picea abies L.) can be used as a geochemical archive for the purposes of historical and recent pollution of atmosphere by Mercury (Hg). The research was realized during the year of 2013 (January to June) in the the capital city of Prague. Šumava National Park was selected as a reference site. In total, forty eight cores of Norway spruce were sourced from five locations for the Hg analysis. Three cores were obtained from each tree from the following cardinal points: the north, east and south-west. The investigated sites have been significantly different in amount of Hg measured (ANOVA, p < 0,001). There was found also negative correlation among the amount of Hg and phosphorus (P) (r = - 0,66; p < 0,002). The highest concentrations of Hg were measured at "Krematorium Motol" site (up to 14,2 ng.g-1 ). On the contrary, the lowest concentration of Hg was recorded both near the former incineration plant at the site "Pod Spalovnou - Vysočany" (1,1 ng.g-1 ) and at the reference site in the Šumava (1,2 ng.g-1 ). Increased values of Hg in the investigated tree rings in the 50's up to the late 70's of the 20th century is probably caused by the former industrial era connected with coal-fired power plants and ore processing. The...
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Historical acid deposition as a predictor of current growth trends in montane forests in the Krkonoše Mts.
Procházková, Kateřina ; Tumajer, Jan (advisor) ; Vejpustková, Monika (referee)
This diploma thesis is focused on mountain Norway spruce (Picea abies) forests and their sensitivity to acid deposition, which culminated in Czechia during the 1980s. Acid deposition negativelly affects tree growth resulting in high mortality and poor health status of the entire forest stands. Mountain forests provide numerous important ecological services, which increses the need for understanding of the processes affecting their growth. The thesis examines the interaction between acid damage in the past and current growth trends and the resistance of mountain forests to current climate extremes (mainly to the effects of drought). The empirical part of the research is based on data on trends in tree-rings widths over the last two decades together with historical data of defoliation monitoring. Tree-ring width data were sampled using dendrochronological methods in the field. For this research, I selected plots along two altitudinal transects in the Krkonoše Mts. - Pec pod Sněžkou and Špindlerův Mlýn. Defoliation data were extracted from the long-term MONBASE database from the Institute of Forest Ecosystem Research (IFER). The statistical method of correlation analysis was used in order to determine the relationship between acid deposition and current tree growth. The most important correlated...
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Long-term disturbances in temperate mountain forests and their representation in various proxy data
Pavlišová, Adéla ; Kuneš, Petr (advisor) ; Moravcová, Alice (referee)
In this work, I present the main disturbance agents affecting temperate mountain forests in Central Europe - wind, bark beetles and fires, and I draw attention to their interdependence. I primarily deal with the description of disturbances, their consequences, ecological contribution, and climate influence on their action. With climatic warming, the extent, intensity, and frequency of disturbances increase. Hence, it is important to understand their role in the past to prepare for the future development of our forests. Proxy data (indirect data) provide past evidence for disturbances, but their interpretation value differs. They inform us about a different time and spatial scale with varying degrees of accuracy. All the methods that I mention in my work provide us, to some extent, with climate proxy data that is closely related to the disturbance regime. Only some directly prove the disturbance, for example, through sedimentary charcoals findings. My work aimed at indicating possible complications but also the advantages that arise when combining individual methods.
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The morphology and activity of selected avalanche paths in the Hrubý Jeseník Mts. and the Králický Sněžník Mts.
Krause, David
The occurrence of avalanche paths is usually frequent in alpine environment, but it is also present in mid-mountains such as the High Sudetes. The submitted master thesis is focused on avalanche paths in the Eastern High Sudetes. The morphometric analysis of 8 paths was accomplished to determine their characteristics and comparison with statistical verification. The dendrogeomorphological analysis and further geomorphological mapping was performed in 2 selected paths (Sněžná kotlina and Králický Sněžník) to cover their avalanche activity frequency and to find relationship between their activity and morphology. The results of this study show that there is a strong difference between two groups of avalanche paths in the Eastern High Sudetes. The Sněžná kotlina and The Králický Sněžník avalanche paths are longer and narrower than the other paths. They also have higher elevation difference. The comparison of these two paths performed by dendrogeomorphology indicates higher avalanche activity frequency in the Sněžná kotlina path, which was strengthened after strong avalanche event in 2004. It is assumed that the Sněžná kotlina path contains advanced avalanche landform, which is a long gully, probably also affected by debris- flows in the past. On the other hand the Králický Sněžník path is rather less...
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Quantitative vessel parameters of broadleaves as a tool for reconstruction of physical geographical processes
Tumajer, Jan
Trees adjust wood anatomical structure to environmental conditions, predisposing time series of quantitative wood anatomical parameters to be valuable source of palaeoenvironmental information. In this doctoral project we analysed the response of vessel parameters of i) floodplain Quercus robur to groundwater level fluctuation, hydroclimate variability and extreme events (droughts and floods), and of ii) Betula pendula to mechanical damage caused by various disturbances. Although climatic signal as well as pointer years stored in tree-ring width chronologies of Quercus robur largely differ between sites, quantitative vessel parameters contain spatially- homogenous positive signal of previous year summer temperature and current year winter/early spring temperature. The only between-site difference in wood anatomical chronologies is negative effect of moisture on vessel size in floodplain, which does not occur in not-flooded lowland sites. We suggest that while tree productivity benefits from high water availability, the wood anatomical structure of Quercus robur is constrained by high soil water saturation in floodplain zone. In addition, the response of tree-ring widths to moisture availability is not uniform inside single stand, but subgroups of trees with completely opposite response coexist...
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Assessment of the rate of vegetation succession at abandoned stone quarries using dendrochronology
Derková, Nikola ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
Dendrochronology is a reliable method of determining the age of a stand. In this thesis, dendrochronology is used to assess rate of vegetation succession in abandoned granodiorite quarries. There were selected eight localities in the study area, each with several sites. At each site there were four - five optically oldest trees selected, from which cores were taken using increment borer. A total of 79 increment cores were analyzed. The obtained age of trees was compared with known age of abandonment and a sequence of aerial photographs, showing history of sites since abandonment. As the results show, tree vegetation is attached in the area after approx. 3 - 7 years from the end of disturbance. We observe continuous stand in the area after approx. 12 years from the end of disturbance.
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