MINERAL NUTRITION AND BIOLOGICAL PRODUCTIVITY OF WHITE BIRCH IN ONTOGENY IN NORTHERN EURASIA
Integrated physiological analysis of forest taxation tables of white birch stands of Northern Eurasia was conducted to obtain quantitative data of net photosynthetic productivity (NPP), carbon deposition (CD), mineral (MP) and biological productivity (BP) of plants at organism level in ontogeny. Forest inventory data on the weight of roots, leaves, and trunk and branch wood was recalculated per plant by the age and used to determine the physiological indices. Leaf area was defined by weight method, NPP according to A.A. Nichiporovich, and CD by a leaf area unit according to K.S. Bobkova and V.V. Tuzhilkina. A detailed analysis of the active part of root system and roots’ MP determination were performed according to I.A. Muromtsev and V.M. Lebedev considering Ye.V. Lebedev’s methodology developments. BP and MP quantitative data were obtained at organism level in the ontogeny at the age from 5-10 to 80-100 years. On average in ontogeny the highest rates of NPP were revealed in Ukrainian Polesye, that of BP and MP for P, K, Ca and Mg in Lithuania, and of MP for N in the centre of European Russia. In all regions, NPP, MP and BP decreased with age. The revealed regularities were observed in all studied stands of North Eurasia from the Baltic Sea to East Siberia. The proposed method of converting forest taxation data into physiological data simplifies significantly the obtaining of quantitative characteristics of leaves and roots activity at organism level, and may be used as theoretical basis to program white birch stands’ productivity.