The aim of this study was to obtain data for elaboration of methods that would be suitable for detection of assimilative apparatus damage, if the damage is still in its latent phase. The needles are covered with epicuticular waxes, which have a protective function, but are also damaged by air pollution first.

The studies of grass communities, which spread in deforested areas, also involved observations of soil thermal regimes. Three sites were chosen in order to determine differences in diurnal and seasonal variations of soil temperatures: (1) open site (barren) without plant cover, (2) site covered by a young, lower and thinner stand of Avenella flexuosa, and (3) old, dense stand of Calamagrostis villosa with a layer of plant litter on the soil surface. Soil temperatures were measured at the soil surface and in the soil depth of 5 and 10 cm. In summer months, the greatest differences in maximal temperatures recorded at the soil surface and at the 5, 10 cm depth between the bare site and the old stand of C. villosa represented 21.6, 15.9, 12.4 deg C, respectively. Soil temperatures measured in the bare plot in autumn months were lower than those in grass stands.

Ammonium and nitrate concentrations in soil were determined in the initial stage of grass stand formation and in old closed grass stands (Avenella flexuosa, Calamagrostis villosa). Higher concentrations of both ammonium and nitrate ions were found in the 0-10 cm soil layer in comparison with the deeper soil layer of 10-20 cm. The amounts of NO3-N and water-soluble NH4+N generally represented only a small part of total mineral nitrogen in samples just removed. Presented data indicate seasonal fluctuations in ammonium and nitrate concentrations in soil.

The planned supraregional biocentre (SRBC) is a support to the system of landscape ecological stability. The sense of this long-term complex project consists in learning features of the ecotope and dynamics of the forest in its present natural and cultural forms and in all existing stages. A draft management plan will be worked out on this basis for the planned SRBC forest area of 1000 hectares, focused on the dynamic ecological stability.