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Результаты 311-320 из 347
Pollution prevention in Colorado commercial greenhouses
1998
Panter, Karen L. | Newman, Steven Earl | Waskom, R. M (Reagan McTier)
FTIR- and UV-spectroscopic study of bromine oxides and their photoisomerization at low temperatures
1998
Kölm, J. | Engdahl, A. | Schrems, Otto | Nelander, B.
Low temperature spectroscopic studies and ab-initio calculations of BrOBr and BrBrO
1998
Kölm, J. | Schrems, Otto | Beichert, P.
Allometric relationships between stem volume and the biomass of Norway spruce
1998
Pokorny, R. (Akademie Ved, Brno (Czech Republic). Ustav Ekologie Krajiny)
The objectives of this study were (I) to establish allometric relationships between the stem volume and biomass of the stem, branches, leaves and the leaf area, and crown dimensions of individual trees, (II) to determine the relative aboveground biomass distribution, (III) to determine the vertical gradient of the specific leaf area and (IV) to estimate the aboveground stand biomass and the leaf area. Diameter at 0.3m height above ground and height of each tree were measured as the basic biometrical characteristics. The coefficient of the shape of the trunk was found by Huber's method.
Показать больше [+] Меньше [-]Comparison of soil thermal regimes in a deforested area with various grass cover in the Beskids Mts. [Czech Republic]
1998
Tuma, I. (Akademie Ved, Brno (Czech Republic). Ustav Ekologie Krajiny)
The studies of grass communities, which spread in deforested areas, also involved observations of soil thermal regimes. Three sites were chosen in order to determine differences in diurnal and seasonal variations of soil temperatures: (1) open site (barren) without plant cover, (2) site covered by a young, lower and thinner stand of Avenella flexuosa, and (3) old, dense stand of Calamagrostis villosa with a layer of plant litter on the soil surface. Soil temperatures were measured at the soil surface and in the soil depth of 5 and 10 cm. In summer months, the greatest differences in maximal temperatures recorded at the soil surface and at the 5, 10 cm depth between the bare site and the old stand of C. villosa represented 21.6, 15.9, 12.4 deg C, respectively. Soil temperatures measured in the bare plot in autumn months were lower than those in grass stands.
Показать больше [+] Меньше [-]Determination of soil hydrolimits in spruce stand soil profile in the Beskids Mts. [Czech Republic]
1998
Novak, F. | Kalcik, J. (Akademie Ved, Ceske Budejovice (Czech Republic). Ustav Pudni Biologie) | Rauch, O.
The soil water retention potentials and other hydrolimits of individual soil horizons of podzolized soil were determined in the stand of Picea abies (Mecuvka, the Beskids, Czech Republic) on godulic sandstone. Different hydropedologic characteristics for the individual soil horizons were found. Extreme values were detected for the albic E horizon, which importance for water and nutrient status of forest stand on podzolic soil is discussed.
Показать больше [+] Меньше [-]Long-term influence of enhanced UV-B irradiation on photosynthetic characteristic of Norway spruce (Picea abies) in the conditions of the Beskids Mts. [Czech Republic]
1998
Sprtova, M. | Marek, M.V. (Akademie Ved, Brno (Czech Republic). Ustav Ekologie Krajiny)
The cloned saplings of Norway spruce (7 years old) were exposed to ambient UV-B irradiation or enhanced BV-B irradiation (+25 %) continuously over three growing seasons. Comprehensive analysis of CO2 assimilation and chlorophyll a fluorescence was performed at the end of the third growing season to evaluate the influence of enhanced UV-B irradiation. The analysis resulted in observations of decreased photosynthetic activity, mainly of RUBISCO activity, as a result of long-term influence of enhanced UV-B irradiation. Morever, the deep impact of enhanced UV-B irradiance on the level of electron transport and thus enhanced sensitivity to photo-inhibition was demonstrated.
Показать больше [+] Меньше [-]A study of growth and morphology of Athyrium distentifolium growing in different environmental conditions in the Beskydy Mts. [Czech Republic]
1998
Pande, K. (Ithaca College, New York (USA). Dept. of Biology)
Athmospheric deposition and soil solution chemistry on plots of third monitoring level in the Sance watershed, Beskids Mts. [Czech Republic]
1998
Moravcik, P. (Ustav pro Vyzkum Lesnich Ekosystemu, Jilove u Prahy (Czech Republic))
Possibilities of using ground basic rock flours in forestry
1998
Vavricek, D. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic))
Surface liming even in higher doses did not affected soil Ph and improving the content of Mg and Ca was only temporary. Spot fertilization by fine-ground amphibolite is significant particularly from the aspect of long-term affects. Short-term affects manifested themselves slightly but in the whole system of particular parameters. Application of higher amounts (3 kg.ha-1) of amphibolite has its substantiation in the future.
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