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The effect of elevated air CO2 concentration on water regime and transpiration of Norway spruce
Valouch, Ludvík ; Pokorný, Radek ; Tomášková, Ivana
Under the elevated CO2 air concentration, changes in physiological processes and morphology were evident in relatively short time. Direct measurement via heat pulse method proved reduction of specific sap flux throw the stem in the first year of cultivation in elevated CO2. SSF in both treatments was comparable in the next tree years. During the sixth year of fumigation, higher transpiration rate in trees growing under elevated CO2 was recorded. It was implication of larger bearing leaf area, larger conducting vessels area on the in crosscut stems section and larger root absorbed area. Continuously sap flow measuring of sun and shaded part of the crown was found that SSF of higher crown part was higher in both treatments. Average hydraulic conductance soil-leaf (GTsa) was 1,4 times higher in sunny part of the crown than estimated for the whole crown in ambient treatment A (ambient [CO2] concentration). Difference in hydraulic conductance between the upper and lower crown part of the E treatment (doubled [CO2] concentration of A treatment) was not so pronounced.
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Krátké periody světelných skvrn jsou při indukci fotosyntézy u smrku ztepilého účinnější
Košvancová, Martina ; Urban, Otmar
Plants growing in the forest understorey are subjected to both prolonged low diffuse background light and transient lightflecks, which provide high light intensities for a few seconds or minutes.The photosynthetic response to fluctuating irradiances is dependent on the following main features of: 1) photosynthetic induction response to a rise in the irradiance, 2) ability to maintain photosynthetic induction under low-light conditions, which allows a plant to better exploit the next lightfleck, 3) stomatal response to light intensity, and 4) ability to extend the photosynthetic activity into the shade period immediately following a pulse of high light, i.e. post-illumination CO2 fixation. In this study we determined the impact of oscillating irradiance with different times of period on the activation and deactivation of CO2 assimilation processes and light use efficiency during the lightflecks.
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Sledování aktivity a množství enzymu Rubisco v jehlicích smrku ztepilého během dne
Hrstka, M. ; Petrů, E. ; Urban, Otmar
Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase; EC 4.1.1.39) enzyme catalyses caboxylation of D-ribulose-1,5-bisphosphate (RuBP), the first step of Calvin cycle, in competition with oxygenation of RuBP that leads to photorespiratory pathway. We estimated diurnal changes of Rubisco initial and total activities as well as Rubisco amount under the different light conditions to find the mechanism of Rubisco activity regulation in Norway spruce needles.
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Remote-sensed monitoring of norway spruce forest ecosystems
Malenovský, Z. ; Cudlín, Pavel ; Moravec, Ivo
This contribution informes about methods and preliminary results of the project following objectives:Investigate possibilities of the recognition of individual types and periods of multiple stress response behaviour and spectral properties of Norway spruce (Picea abies (L.) K a r s t.) at the shoot and crown levels through spectrometric measurements of needles, shoots and branches, supported by the foliar pigments and cellular compound laboratory analyses, and through analysis of canopies from remote-sensed hyperspectral imagery.Propose a method for estimation and interpretation of multiple stress response history and crown-status assessment of Norway spruce forest stands by the remote sensing approach, via analysis of hyperspectral images.
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Central-European mountain spruce forests: regeneration of tree species after a bark beetle outbreak
Jonášová, Magda
Two different approaches were applied to mountain spruce (Picea abies) forests attacked by bark beetle in the Šumava National Park (Czech Republic): (1) a small portion of the stands was left without intervention, relying upon natural regeneration, and (2) traditional technical measures were adopted, in which attacked trees were felled and removed. The results confirmed that the original tree species of the mountain spruce forests regenerate well under dead canopy and the bark beetle outbreak could even be considered as a tool for the restoration of their natural character.
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