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.

Data necessary for the determination of the proportion of various types of branching in stands under study, their variability within a tree, accuracy of classification of the type of branching, damage to particular types of branching due to breakage and initial age for their reliable recognition were obtained according to method from 1,336 trees situated in 11 trial plots in the region of the Beskids. Statistically significant differences were determined in the diameter and height increments for particular types of branching.

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.

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.

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.