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1	Stabilní izotopy uhlíku v letokruzích smrku jako marker napadení stromu patogenní houbou. / Carbon Stable Isotopes in Spruce Tree Rings as a Marker of Pathogenic Fungal Attack of Trees. NECUDOVÁ, Lucie January 2013 (has links) Trees are long living plants, which use carbon from the air and hydrogen and oxygen predominantly from soil water for their growth. They deposit these elements largely into a wood where they may persist for thousands of years. Tree growth is influenced by environment, especially by air temperature and precipitation. These factors have an effect on stomatal conductance and photosynthesis rate which influence carbon stable isotope ratio (13C/12C) in the tree tissue. This thesis is focus on stable carbon isotopes in tree-rings of Norway spruce attacked by honey mushroom, and Norway spruce which doesn?t show any signs of disease. The hypothesis of the thesis is based on an expected difference in carbon isotope fractionation during photosynthesis between the spruce attacked by honey mushroom and a ?healthy? spruce. The difference in isotope fractionation could be caused by water deficit induced by honey mushroom disease in the tree. We expect that the attacked spruce defends against water loss by closing stomata, and it could lead to lower CO2 concentration in the needles and higher ?13C value in tree-rings biomass The stable carbon isotope analysis (IRMS) was done on tree-rings of four spruce pairs, each one including an attacked spruce and spruce which didn?t show any signs of disease. Carbon isotope ratio of early wood, late wood and in biomass of the whole annual increment was measured. In contrary to our hypothesis we did not fined any systematic difference in isotopic composition between the attacked spruce and the spruce which did not show any signs of disease.
2	Demography and dendrochronology of a disjunct population of eastern hemlock in Southwestern Ohio Johnson, Marie 28 August 2018 (has links) No description available. Biology Botany Climate Change Conservation Demography Ecology Forestry eastern hemlock hemlock disjunct demography dendrochronology tree rings climate isolated population HWA hemlock woolly adelgid Clifton Gorge John Bryan Cantwell Cliffs management plan conservation edge population Yellow Springs tree core

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Stabilní izotopy uhlíku v letokruzích smrku jako marker napadení stromu patogenní houbou. / Carbon Stable Isotopes in Spruce Tree Rings as a Marker of Pathogenic Fungal Attack of Trees.

Demography and dendrochronology of a disjunct population of eastern hemlock in Southwestern Ohio