DYNAMICS OF NITROGENOUS COMPOUNDS ACCUMULATION IN <i>BETULA PENDULA </i>AND B. <i>PENDULA </i>VAR. <i>CARELICA (BETULACEAE) </i>SEEDLINGS OVER A GROWING SEASON
The study of nitrogenous compounds dynamics in 1-year-old seedlings of Betula pendula var. carelica (Mercklin) Hämet-Ahti and B. pendula Roth seedlings of the same age revealed in Betula pendula var. carelica, compared to B. pendula, higher nitrogen availability to organs, higher concentrations of the non-protein amino acid citrulline in the trunk part; glutamic acid (a central link in nitrogen metabolism) was maintained at a certain level in leaves during growth period.