USE OF PHYTO-INDICATION METHODS IN ASSESSMENT OF RELATIONSHIP OF NITROGEN CONTENT IN PLANTS WITH THEIR GROWING CONDITIONS (ON THE EXAMPLE OF FORESTS IN THE SOUTHERN MOSCOW REGION)

The relationship of the chemical composition of plants with conditions of their growth and their contribution to soil nitrogen during dying is revealed. The study was based on the materials of geobotanical relevés of 15 forest plots in the subzone of coniferous-deciduous forests in the south of the Moscow Region. Two methods of phytoindication were used. The type of habitat conditions was determined according to the Vorobyov-Pogrebnyak’s indicator species. The point values of soil nitrogen richness were calculated according to the Tsyganov’s scale. The nitrogen content in plant organs, samples of forest litter and soil was determined using gas chromatography. The analysis of the data showed a correlation between the types of forest vegetation conditions and the points on the Tsyganov’s nitrogen richness scale for the conditions of the southern Moscow Region. The nitrogen content in the forest litter has a high reliable relationship with the types of habitat conditions. It is shown that plants from the habitats which are richer in nitrogen according to the Tsyganov’s nitrogen richness scale have a higher nitrogen content in leaves, stems and rhizomes than plants growing in poorer soil conditions. The conducted study has shown the validity of using phytoindication scales for the assessment of soil conditions.