Stability of development of birch forests of grass-type in industrial pollution zone

The birch stands of grass type, II-III growth class, V age class, growing in Krasnoyarsk forest-steppe under the influence of emissions of alumi-nium works and heating and power plant, were stu-died. The similar stand in Magansk forestry was chosen as control. The aim of this study was to characterize accumulating capacity of birch stands and evaluate their developmental stability by leaf plate fluctuating asymmetry. The experiment was carried out in late season in 2013. In solid sedi-ments at the open areas, under the canopies and in birch leaves the contents of heavy metals and alu-minum was determined by certificated procedures М 04-64-2010 and М 03-07-2009. Fluctuating asymmetry indices for Betula pendula leaves were calculated according to the method of V.M. Zakha-rov et al. Cleaning efficiency of birch stands were found by a formula K=(O-C)/O·100% from the study of L.S. Dochinger. It has been found that in one-and-a-half-kilometer zone from Krasnoyarsk alumi-num works on the ground surface 26-122 t/hectare of technogenic dust may be deposited during the season. Under the canopy of studied stands 1- 5 t/hectare of the dust were accumulated. In the birch leaves considerable amounts of aluminum and heavy metals were stored, exceeding their normal contents. Coefficients of cleaning efficiency of birch stands varied from 93 to 98 % that con-firmed the great sanitation importance of these stands. The maximal values of fluctuating asym-metry indices were 0.07 that pointed out ecological disturbances in these grass-type birch stands and appearance of unstable development of physiologi-cally active parts of the stands.