It was performed the study of the humus forms, quantity and pedochemical characteristics, further the study of plantation growth, and the dynamics in the period of 1994-1999. Negative impacts of the bulldozing were documented, acidification in the period 1994-1999 and the ameliorative role of the birch stand as well

Yellowing of trees with current year needle-class remaining green shows typical symptoms of magnesium deficiency. The chemical analysis proved severe deficiency of magnesium and mild deficiency of calcium in needles and forest soils indeed. This corresponds to the new forest decline as observed in the 1970s and the 1980s in some regions in Germany and France. Other contributing factor breaking out yellowing at that extent at particularly short time is not known. The problem is even increasing, because yellowing has recently appeared also in other mountain localities in Central Europe even though in smaller scale

Results on germination, growth and mortality of Norway spruce seedlings during period 1994-2000 in various types of soil cover were summarized and evaluated. The years 1992 and 1995 were recorded as high seed production years, while the year 2000 is considered as the low seed production year. In 1999 natural seedlings from various soil covers were examined for lateral root and root tip development. The results of germination and surviving of Norway spruce seedlings are discussed in relationship with the stage of the decline of Norway spruce ecosystems

The average defoliation of the sites located in the western part significantly increased in 2000, probably as a result of massive needle yellowing and shedding, and the G/A bud ratio decreased for all of the sites what reflected in reduction of crown regeneration. We suppose that a further increase of crown defoliation due to exceedance of stress threshold may trigger tree defensive reactions and replacement of the loss of assimilative organs

45 sites were selected and sampled on the transects and according to the first results of the spatial analysis, 15 more sites were added where useful for the optimal interpolation. Topsoils were sampled including both the soil organic horizons and the more superficial mineral horizon, frequently E, if reached. The depth of the organic horizons, the grass cover, ranked by its hydrophilic character, related to the incipient hydromorphy visible where Norway spruce is more declining, and the Norway spruce health status were systematically recorded

The aim of the experiment was to find out the influence of various thinning regimes on health condition of young stands of Norway spruce under the stress of air pollution. The experiment is based on comparative method. The series consists of three comparative plots with different thinning regimes. The comparative plot 1 is a control plot without thinning. The program with heavy thinning from below has been tested on the plot 2 and the program based on one very heavy thinning in the young age and longer periods was applied in the stands of plots 3. Health condition of experimental stands was assessed on defoliation in 1982, 1981 and since 1987 annually on both series