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The present study is the first attempt to carry out an inventory of greenhouse gas (GHG) fluxes in the forests of Estonia. The emission and uptake of CO as a result of forest management, forest conversion and abandonment of cultivated lands in Estonia was estimated. The removal of GHG by Estonian forests in 1990 exceeded the release about 3.3 times. Changes in the species composition and productivity of forest sites under various simulated climate change scenarios have been predicted by using the Forest Gap Model for the central and coastal areas of Estonia. The computational examples showed that the changes in forest community would be essential.2

Investigations in a 75-85-year-old Scots pine stand were performed on a territory influenced over 40 years by alkaline dust pollution (pH 12.3-12.7) emitted from a cement plant. Sample plots were located at distances of 2, 3, and 5 km E of the emission source and a control sample plot was selected on an unpolluted territory 38 km W of it. We studied soil properties and the anatomical structure, mineral nutrition, and pigments in Scots pine needles. The alkaline dust pollution has affected the biogeochemical cycling in the forest ecosystem, increasing the pH and total Ca, K, Fe, Mn, and Mg and decreasing N, C, organic matter, and C/N compared to the unpolluted soils. Alkalization and changes in the nutrient composition of soil had caused serious disbalances in nutrient availability and in the mineral composition of trees. Deficiency in foliar N and Mn and excess of K, Ca, and Fe contents had caused a decrease in the average chlorophyll concentrations. Carotenoids seemed to be more tolerant both to changes in soil and needle nutrient composition. The Ch1 a/Ch1 b ratio in needles was found to have declined. With the alkalization of the environment the total area of the needle cross-section, needle thickness, and mesophyll area had also decreased compared with control. Differences in the anatomical characteristics of needles between the polluted and unpolluted areas were significant in the oldest needles. The decrease of mesophyll was associated with the content of chlorophylls and correlated with N concentrations in needles. [ABSTRACT FROM AUTHOR]

The content of nutrients in soil and needles of second-growth pines was studied on dunes of different relative height (23 m, 10 m, 5 m) in the coastal area of the Baltic Sea in South-West Estonia. Results give an insight into the nutrition status of pines on the plain and on the slopes and tops of dunes. The data obtained indicate that the logarithmic relationship is statistically significant between N, K, and Mg contents in the needles and soil and the height of the sample point on the dune. Deficiency of nutrients for the growth of pines, especially that of N and K, had developed on dunes. The study showed that on dunes the nutrition conditions and concentration of nutrients in needles depend significantly on the relative height of the growth site on the dune. [ABSTRACT FROM AUTHOR]