Photosynthesis, Mineral Nutrition and Productivity of Decidious and Coniferous Dendroflora Species in the Central Part of the Russian Plain

An ecological and physiological retrospective transformation of the data from the dry mass tables obtained by V.A. Usoltsev has been carried out for 7 coniferous and deciduous species (Larix sukaczewii, Picea abies, Pinus sylvestris, Betula alba, Quercus robur, Tilia cordata and Fraxinus excelsior) in the central part of the Russian Plain. In the age range from 5–20 to 80–200 years, the indicators of net photosynthetic productivity, net mineral productivity, net primary production, carbon sequestration, free oxygen emission and biological productivity have been determined at the organism level. When establishing these parameters, plants have been considered from the standpoint of ecology and the structure of a modular organism. The calculation of net mineral productivity has been carried out according to I.A. Muromtsev and V.M. Lebedev, and the net productivity of photosynthesis has been calculated according to A.A. Nichiporovich. A decrease in all physiological parameters with age has been recorded at a simultaneous increase in the ratio of root to photosynthetic potential (as an adaptive response to a decrease in the availability of nutrients). In all species, upon reaching the age of 20–30 years, a sharp decrease in the absorption activity of the roots has been revealed, which has stabilized at an extremely low level by the age of 50–60 years. The relationship between the listed plant indicators and their age for the studied species has been negative, and the relationship between mineral and biological productivity has been characterized as highly positive. In comparable age periods (30, 60 and 90 years), the studied species differed in nitrogen absorption by the root system by 21.7–28.0 times, in net photosynthetic productivity – by 4.4–7.0 times, in the value of net primary production – by 1.8–6.2 times, in nitrogen absorption – by 3.2– 6.1 times, in carbon sequestration and free oxygen emission – by 1.8–6.2 times, and in the mass of the whole plant – by 2.4–3.9 times. According to the accumulated dry mass, tree species at 90 years of age have been arranged in the following descending order: oak, spruce, larch, pine, linden, ash and birch.