خيارات البحث
النتائج 311 - 320 من 333
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.
اظهر المزيد [+] اقل [-]Regeneration processes of a Norway spruce virgin forest of the Stata nature reserve Pilsko in the Oravian Beskids Mts. [Slovak Republic]
1998
Saniga, M. (Technicka Univ., Zvolen (Slovak Republic). Lesnicka Fakulta)
Physiological aspects of the health state of Norway spruce using different silvicultural concepts
1998
Kmet, J. | Jaloviar, P. (Technicka Univ., Zvolen (Slovak Republic). Lesnicka Fakulta)
The sample trees from two stands managed by different management systems - shelterwood and selection systems, and two generations within each stand, were compared. The evaluation of the potential acidity and conductivity of dry-mass extracts (KSE) proved an adverse effect of environment on the maternal stand in the shelterwood forest. The KSE-values are systematically higher in samples taken from the young as well as mature sample trees in the selection forest. Despite the limited duration and extent of the investigations, a better ecological stability of the selection forest as compared with the shelterwood one was observed.
اظهر المزيد [+] اقل [-]Air pollutants of SO2 and total potential deposition of sulphur of the forest territory Moravian-Silesian Beskids Mts. [Czech Republic] in 1996
1998
Hadas, P. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic))
According to the geostatistical methods annual sums of precipitation, mean annual concentrations of SO2, total potential deposition of sulphur as inputs to the mountain forest ecosystem of Moravian-Silesian Beskids on the spatial level in 1996 were derived. For this purpose, all possible meteorological and monitoring stations in the surroundings of the cesearch teiritory were used.
اظهر المزيد [+] اقل [-]Use of epicuticular waxes changes for detection of latent forest decline
1998
Bednarova, E. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Ustav Ekologie Lesa)
The aim of this study was to obtain data for elaboration of methods that would be suitable for detection of assimilative apparatus damage, if the damage is still in its latent phase. The needles are covered with epicuticular waxes, which have a protective function, but are also damaged by air pollution first.
اظهر المزيد [+] اقل [-]Synusiae of cambioxylophages of subdominant Norway spruce trees stressed by root-fungal pathogens
1998
Kula, E. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Fakulta Lesnicka a Drevarska) | Zabecki, W.
Some 30 species of cambioxylophages with the dominant position of Pityophthorus pityographus, Polygraphus poligraphus, Pityogenes chalcographus, Molorchus minor and Obrium brunneum were recorded on subdominant trees attacked by Armillaria sp. and Heterobasidion annosum. The stress induced by fungal pathogens on subdominant trees causes unfavourable conditions for the development of Ips typographus and increases attractiveness for P. poligraphus and M. minor. Species of P. chalcographus and P. pityographus response indifferently.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Mineral soil nitrogen concentration in grass stands after deforestation
1998
Zahora, J. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic))
Ammonium and nitrate concentrations in soil were determined in the initial stage of grass stand formation and in old closed grass stands (Avenella flexuosa, Calamagrostis villosa). Higher concentrations of both ammonium and nitrate ions were found in the 0-10 cm soil layer in comparison with the deeper soil layer of 10-20 cm. The amounts of NO3-N and water-soluble NH4+N generally represented only a small part of total mineral nitrogen in samples just removed. Presented data indicate seasonal fluctuations in ammonium and nitrate concentrations in soil.
اظهر المزيد [+] اقل [-]Research of basic issues of supraregional biocentre in Knehyne - Certuv Mlyn, the Moravian-Silesian Beskids Mts. [Czech Republic]
1998
Tesar, V. (Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Fakulta Lesnicka a Drevarska)
The planned supraregional biocentre (SRBC) is a support to the system of landscape ecological stability. The sense of this long-term complex project consists in learning features of the ecotope and dynamics of the forest in its present natural and cultural forms and in all existing stages. A draft management plan will be worked out on this basis for the planned SRBC forest area of 1000 hectares, focused on the dynamic ecological stability.
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