Radiation regime is the important part of the energy flow through the stand structure. The goal of the radiation regime studies in the forest stand is to create and develop the technology for radiation measurements and to estimate the impacts of stand density on the radiation regime. The experiment is carried out the Experimental research site Bily Kriz in the Moravian - Silesian Beskydy Mts. with a Norway spruce monocultural stand. Intensities of photosynthetic active radiation, global radiation and intensities of incident and transmitted photosynthetic active radiations through the stand were measured.

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.

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.

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.

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.

This contribution deals with the relationship evaluated on the basis of 32 permanent monitoring plots. Tree volume increment as a total "brutto" and also as a pure "netto" change for 1 ha is defined. The first one includes also the influence of felling, mortality and increment ingrowth, second one includes only changes due to the growth process. Relationship of increment to stand variables is investigated bz stepwise regression. A more higher correlation to defoliation was found, less high to age, site index and altitude.