Results of the statistical tests showed the spectral disparity of the production part and highly damaged juvenile part of the spruce crown. A spectral difference of the juvenile and production crown part at early stress could not be shown. A low multiple stress impact was assessed for 75 randomly selected Norway spruce trees of the first AISA image. In case of the second AISA image occurrence of Cu-Zn sulphide mine partly influenced the crown status of the neighbouring spruce ecosystems

Ectomycorrhizal types were quantified in soil cores taken from 0-5 cm horizon. Nine ectomycorrhizal types were distinguished on roots of pines grown close to the copper smelter, 17 on trees grown in vicinity of aluminium smelter versus 25 found on trees grown near phosphate fertilizer plant and from control trees. Molecular studies were performed to give a greater resolution of how emission from different sources influenced mycorrhizal fungal community of Scots pine

Five permanent plots in pine and spruce stands were established at beginning of the 90s. The sites were situated in a gradient of air pollution level, from the south to the north of Poland. There are presented changes in SO2 and NO2 concentration in the air as well as loads of acidic compounds and the exceedance of critical loads in the period of 1993-2001. Response of the forest ecosystems was evaluated by changes in health status of trees and changes in biodiversity at forest permanent plots. The comparative study revealed an improvement in the health condition of trees and a tendency of ecosystems to regenerate due to greater than 30% decrease in emission in the last decade

The need to assess the role of terrestrial ecosystems in the global C cycle and the potential change of this role as the atmospheric concentration of CO2 increases attracted considerable scientific attention over the recent decade. In order to assess ecosystem responses as a whole and to evaluate the potential role of forests and tree communities as a carbon sinks, the below-ground response to increasing levels of CO2 must be addressed

Increased ozone sensitivity of larger soil-growing trees with growth in the multi-year exposure was a result of several interactive senescence-related physiological factors: lower net photosynthesis to stomatal conductance ratio at the end of the growing season promoted high ozone uptake and low photosynthetic carbon gain, leading to onset of visible injuries and impaired bud formation. This was expected to affect negatively the early growth of the next year foliage, This clone showed a major change in allocation pattern during the early ontogeny at the expense of foliage growth towards the stem height increase

The attention was focused on the diameter increment of beech timber forest growing on the partial plots with various stand density. The individual parts of the originally homogenous stand, were subjected to regeneration cutting of various intensity resulting in several partial plots. On the different partial plots we found different proportions of trees belonging to the individual diameter classes. We also found that the differences between the individual plots were statistically very significant. Beech is a tree species which is capable to continue creating considerable light increments even long after the stand opening

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

Soil microorganisms are important for plant growth and beneficial for the nutrition and the development of a variety of soil animals. Together with soil invertebrates they also improve nutrients availability in soils. Although not frequent in Europe , magnesite emissions can affect the nutritional status of the vegetation and the survival of soil microorganisms as well as other biota locally, and thus may be crucially responsible for the quality of the entire biotic system. The observed gradients of soil microbial characteristics reflect the physico-chemical properties of soils around the magnesite plant and may be used to predict transitory changes during amelioration

There is still limited amount of information about the long-term and interactive effects of increased CO2 and O3 levels on larger forest trees growing under natural or semi-natural conditions. Elevated CO2 and O3 might affect the quality and quantity of leaf litter produced and thus change litter decomposition rates and nutrient cycling in the forest ecosystems severely. In this long-term field experiment we studied the effects of realistically increased CO2 and O3 levels on fine root and mycorrhiza growth in ozone-tolerant and ozone-sensitive silver birch clones by root ingrowth core method. We measured rhizosphere soil CO2 efflux plus assessed the total fungal biomass of fine roots and soil by ergosterol analysis

The results indicate that it is possible to reach a good level of reproducibility in a relatively short time. However, quality assurance procedures allow to know the real status of reliability of the field data. More attention must be given to the Level II indices, to select the really useful and informative ones, and to concentrate on these the didactic efforts