National Repository of Grey Literature 23 records found  previous4 - 13next  jump to record: Search took 0.00 seconds. 
Analýza tvorby dřeva buku lesního (Fagus sylvatica L.) na buněčné úrovni na výzkumné ploše Rájec - Holíkov
Porvalík, Radim
The content of this diploma thesis is the analysis of the formation of beech wood (Fagus sylvatica L.) at the cellular level, ie xylogenesis in the research area Rájec - Holíkov, which is located in the Drahanská Highlands. Specifically, this study focused on the activity of cells in the cambial zone and the differentiation of the new annual ring on individual days (DOY) during the 2016 growing season compared to 2015, when samples were taken (Trephor tool) regularly once a week using so-called micro-bore. Permanent microscopic slides were created from these, which were subsequently examined. The activity of cells in the cambial zone was started in 2015 and 2016 in the last week of April at a temperature of 8.3 ° C. The zone of secondary cell wall (SW) formation and gradual cell lignification was evident two weeks after the onset of postcambial growth until the end of August. After the application of the Gompertz function, the creation of a new annual ring took an average of 91 days in 2015 and its size was 1252.7 μm. The year 2016 was similar, the size was 1229.2 μm. The average time of creation of a new annual ring was higher, namely 117 days.
A study of the behavior of selected metals in affected environments using an isotopic approach
Santos Baieta, Rafael ; Mihaljevič, Martin (advisor) ; Navrátil, Tomáš (referee) ; Tejnecký, Václav (referee)
Metals of anthropogenic origin have consistently polluted the environment. This thesis focuses mainly on highly contaminated soils or tree rings near mines and smelters in Sub-Saharan Africa. However, Portuguese soils were also assessed to study Pb isotopes in post-fire soils. The tracing capabilities of Pb isotopic ratios were employed to determine contamination sources and to evaluate the potential of pine trees as an environmental archive. Several analytical methods were applied, such as catalytic oxidation, Q-ICP-MS, ICP-OES, FEG-SEM/EDS, EPMA, XRD, etc. Soils near smelters located in three different cities [Kabwe (Pb-Zn), Luanshya (Cu, Co), and Selebi Phikwe (Ni, Pb)] exhibited concentrations of metals greatly exceeding those deemed acceptable by the competent authorities. In Kabwe, for example, concentrations of Pb exceeded 16 000 mg kg-1 . In all sites, contamination was shown to be significant only in the upper ±15 cm of soil. Samples of soils taken in remote locations were always clear of contamination. In Luanshya, metal(oid) bearing particles found in the soils were typically spherical and composed of rapidly cooled sulfides and oxides in the flue gas chambers of the local smelter. These were present only in the topsoil. The tree ring record of pine trees in Kabwe was shown to mimic the...
Trends in tree-ring width of treeline trees along latitudinal gradient from subtropics to the Arctic.
Zborníková, Kateřina ; Treml, Václav (advisor) ; Mašek, Jiří (referee)
This bachelor thesis is interested in a tree ring of trees at the treeline from subtropics to the arctic and the main aim of this work is to find if there is a trend in the tree ring width at the treeline along the latidunial gradient. The work/thesis focuses on conifers. The data were obtained from International Tree-Ring Data Bank database, article searches and from the internal workplace database. A total of 9859 annual ring samples were obtained from 153 localities in Europe. Trees of the genus Pine (Pinus), Spruce (Picea) and Fir (Abies) were selected, which dominate the europeans ecotones of treeline. After removing the age trend, the regression of tree ring width and the latitude, were calculated. The results showed that in most cases the tree ring width decreases with higher latitude. However, a small number of tree ring samples from latitudes around 55ř north latitude adds to the uncertainty of this claim.
Tree rings dendrochemistry near Cu smelter
Jarošíková, Alice ; Mihaljevič, Martin (advisor) ; Hojdová, Marie (referee)
Nkana smelter belonged to the main sources of contamination by trace elements (especially Cu and Co) in the area of African city Kitwe (Copperbelt, Zambia). The main objective of this study was to compare elemental and isotopic composition of Zambian soils and tree rings, and to investigate biogeochemical processes between plants and soils in contaminated and uncontaminated environment. Elemental composition (Cu, Co, Cr, Mn, Fe, Zn, Pb, Cd, Hg and Tl) and isotopic composition of Cu (63 Cu/65 Cu) were determined in soils and tree rings of pine trees (Pinus latteri, Pinus kesiya) using ICP-MS , AMA and MC ICP-MS. Our results demonstrated that soils and tree rings were both affected by mining and metallurgical activity. Increasing content of elements with depth is the result of the mobility of the elements in uncontaminated soil profile. Soil from contaminated site had the highest metal contents especially in the upper part of the soil profile as a result of continuous contribution of metallurgical components during long-term smelter operation. Fractionations of Cu isotopes in soils were caused primarily by interactions with plants. Concentration changes that some elements showed in the individual tree rings could be the effect of variable intensity of pollution in the area. In the case of Cu, however,...
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...
Arsenic in tree rings at As contaminated sites
Svoboda, Ondřej ; Mihaljevič, Martin (advisor) ; Vaněk, Aleš (referee)
Kutná Hora and its surrounding environment was affected by mining Ag, later Pb - Zn ore, lasting several centuries. As a result of mining, extreme concentrations of heavy metals and metalloids, especially As, in waters, soils and plants are. The aim of this work was to study the elemental composition of soils and tree rings, including processes between soil and plants on contaminated and uncontaminated area to describe biogeochemical processes between soil and plants. Elemental composition (V, Cr, Mn, Fe, Co, Cu, Zn, As, Cd, Sb, Tl, Pb) were determined in soils and tree rings of Scots pine (Pinus sylvestris) using ICP - MS. The measured concentrations of elements indicate contamination of soils and tree rings due to mining and metallurgical activities. The highest concentrations of As in soil (14 977 mg/kg) were found at contaminated site (Kaňk) at depth of 40 - 50 cm. This locality is situated on the heap, where waste from the mining and processing of ores are deposited, together with minerals and weathering products containing As. The uncontaminated area (Sukov) exhibited the maximum concentration of As in soils 124,38 mg/kg at a depth of 5 - 10 cm, due to the contamination by dust from the contamined sites. The highest concentrations of As in tree rings were determined in the contaminated area...
Impact of being evergreen or deciduous on the wood anatomy of the trees in polar regions during the warm geological period : case study from Upper Cretaceous of the James Ross Island (Antarctic Peninsula)
Chernomorets, Oleksandra ; Sakala, Jakub (advisor) ; Gryc, Vladimír (referee)
Global warming and its influence on the environment has become a popular and widespread issue. Nowadays, an analogy of a high latitude ecosystem during the greenhouse type of climate does not exist. The Cretaceous polar ecosystem gave us a unique possibility of understanding these extreme ecosystems and the specific adaptations of organisms to these conditions. Such types of ecosystem are crucial for a better understanding of possible future climate changes. This thesis focusses on the adaptation strategies of land plants during the Late Cretaceous in the Arctic peninsula. The land plants responded to these specific solar conditionals in two different ways: evergreen or deciduous. The fossil material for this study comes from Brandy Bay and Crame Col, James Ross Island, Antarctic. The material was collected in a continuous sequence from Kotic point to Santa Marta Formation (Cenomanian - Companian). A detailed and systematic analysis was performed on five out of fifty-five samples that well represented the studied region and age: Agathoxylon kellerense, Agathoxylon antarcticus, Araucarioxylon chapmanae, Podocarpoxylon multiparenchymatosum and Phoroxylon sp. Based on the detailed study of Agathoxylon kellerense (sample number AN34) wood anatomy and growth rings structure, adaptation strategies were...
Sestavení letokruhových standardních chronologií z recentních dubů pro Českou a Slovenskou republiku a jejich porovnání se středoevropskými chronologiemi
Prokop, Ondřej
The main objectives of the thesis submitted were to create the missing oak tree-ring chronology for the area of Slovakia, update the existing Czech oak tree-ring chronology, assess their paleoclimatic potential, and find the best way to remove the age trend from tree-ring series. At the same time, the number of sapwood tree rings over time was analysed. As the historical and archaeological material can be represented in tree-ring chronologies by curves from different oak species with different age and from different areas, two comparative studies have been carried out to assess their usefulness for the climate reconstruction. Tree-ring chronologies of four selected oak species (Quercus robur L., Quercus petraea (Matt.) Liebl., Quercus polycarpa Schur., Quercus dalechampii Ten.) from the same region showed a very similar response to climatic parameters; the differences were caused by local site conditions rather than oak species. Further, the recent part of the Czech oak chronology was divided into five couples of sub-chronologies using various categories (altitude, age of trees, tree species, soil moisture, and geographic location). A great similarity of all the sub-chronologies was confirmed by the most significant growth response of oak to the precipitation sum in the period May to July. The thousands-year-long Czech oak chronology, which has been gradually improved in recent years, still showed insufficient coverage of the entire territory of the oak natural distribution range and insufficient replication in the 19th century. A total of 342 newly collected samples from western Bohemia and samples from selected historical structures, mostly belfries, were used to cover the entire natural distribution range in the Czech Republic and to improve the connection of the recent and the historical parts of the chronology. The study was supplemented by the analysis of the number of sapwood tree rings, which confirmed the declining number of sapwood rings in the direction from the west to the east, and showed that the number of sapwood rings does not change over time (5-24). A completely new tree-ring oak chronology for the territory of the Slovak Republic was made up of 276 historical and 1028 recent samples. The chronology ranges from 967 to 2013 and shows strong resemblance with the tree-ring chronologies from the Czech Republic, Austria and Ukraine. As the Czech chronology, it manifests the most significant response to precipitation in the May to July period with a huge drop in correlations around 1980. The analysis of negative pointer years in the chronology revealed 26 periods; the most extreme year was 1947, which stood out in all of the investigated sites. Comparing the resulting chronologies, no significant differences were found among the various ways of age trend removal from tree-ring series in the periods with sufficient replication. This work extends the knowledge about the behaviour of the oak in Central Europe at the level of tree rings. The newly formed tree-ring oak chronology for the area of Slovakia fills the gap in the dense network of European chronologies and together with the update of the Czech oak chronology increases the potential for hydroclimatic reconstructions and the reliability of the dating of historical oak structures and archaeological finds.
Impact of being evergreen or deciduous on the wood anatomy of the trees in polar regions during the warm geological period : case study from Upper Cretaceous of the James Ross Island (Antarctic Peninsula)
Chernomorets, Oleksandra ; Sakala, Jakub (advisor) ; Gryc, Vladimír (referee)
Global warming and its influence on the environment has become a popular and widespread issue. Nowadays, an analogy of a high latitude ecosystem during the greenhouse type of climate does not exist. The Cretaceous polar ecosystem gave us a unique possibility of understanding these extreme ecosystems and the specific adaptations of organisms to these conditions. Such types of ecosystem are crucial for a better understanding of possible future climate changes. This thesis focusses on the adaptation strategies of land plants during the Late Cretaceous in the Arctic peninsula. The land plants responded to these specific solar conditionals in two different ways: evergreen or deciduous. The fossil material for this study comes from Brandy Bay and Crame Col, James Ross Island, Antarctic. The material was collected in a continuous sequence from Kotic point to Santa Marta Formation (Cenomanian - Companian). A detailed and systematic analysis was performed on five out of fifty-five samples that well represented the studied region and age: Agathoxylon kellerense, Agathoxylon antarcticus, Araucarioxylon chapmanae, Podocarpoxylon multiparenchymatosum and Phoroxylon sp. Based on the detailed study of Agathoxylon kellerense (sample number AN34) wood anatomy and growth rings structure, adaptation strategies were...
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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