Seasonal dynamics of the mineral nitrogen forms in mountain-meadow alpine soils

The good agreement between the changes in the concentrations of ammonium and nitrate nitrogen, on the one hand, and the mineralization and nitrification activities, on the other hand, was shown in the annual dynamic cycle of the mobile mineral nitrogen concentrations, the net mineralization of its organic compounds, and the net nitrification in mountain-meadow soils of different ecosystems of the Teberda Reserve. The low nitrification activity in the mountain-meadow soils results in the predominance of ammonium nitrogen in its mineral forms during the entire vegetation period. The importance of the fall-winter-spring period, when the mineralization of organic nitrogen compounds proceeds actively and results in the accumulation of ammonium nitrate in the soil up to the beginning of the vegetation period, was emphasized. Due to the long duration of this period, its average contribution to the total annual mineralization is comparable to that of the vegetation period.