Fine root distribution was estimated in three spruce stands with different stages of forest decline. At all 3 sites in the 0-5 cm layer the density of living fine root mass exceeds the necromass. However, in the deeper soil layer necromass exceeds biomass by a factor of 2-4 at Modry Dul, ca. 3 at Alzbetinka and by more than 8 at Mumlavska Hora. The distribution of root density was reflected in the distribution of root length and the number of root tips in each soil layer for the 3 sites

The analysis of the latest results along with the change analysis reveals that the conditions of Slovenia's forest are considerably stable and that the process of decline has not progressed with the intensity, that had been predicted in the early eighties. Quite favourable conditions are due to prompt actions (selection and sanitary cutting) in the field

Investigations on the bacterial communities associated to ectomycorrhized roots of seedlings from three stands with different degrees of regeneration decline (high, intermediate and low) and from seedlings grown on monoliths obtained from the very same stands have been carried out. The results suggest that forest decline does not influence bacterial biomass associated to seedlings roots but induce a clustering of specific bacterial species adapted to the different degree of forest decline

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

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

Determination of the streses operating on a forest ecosystem demands the use of several bioindication methods. Air quality indicators were assessed from an inventory of forest decline based on the assessment of tree crowns and lichens. Photosynthetic pigments, ascorbic acid and major macro nutrients were studied in mountain pine (Pinus mugo Yurra) needles as indicators of physiological and biochemical stress. Analyses were carried out at selected forest plots and transects in predominantly unpolluted areas within Triglav National Park, Julian Alps, Slovenia. It was assumed that air pollutant input in forest ecosystems is of two kind, e.g. local from the air pollutin sources in the valleys on the North-West part of tha national park and transboundary source at high altitudes