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86 Карпінець Л.І., Лобачевська О.В.

Karpinets L.I., Lobachevska O.V.
Seasonal dynamics of the nitrogen mineral forms content in the shoots of the moss Atrichum un
dulatum (Hedw.) P. Beauv. on conditions of the Ukrainian forest ecosystems
The features of seasonal dynamics of the nitrogen ammonium and nitrate forms content in the
assimilating green and brown senescent parts of shoots of the epigeic moss Atrichum undulatum
(Hedw.) P. Beauv. depending on the microclimatic conditions of the reserve and anthropogenically
RoztochіaUkrainian Roztochia forest ecosystems were
disturbed areas (felling and recreational load) of the
studied. It was determined that in April the amount of ammonium cations was the highest in open areas
of felling under conditions of higher air temperature and light intensity, which significantly induced
biochemical reactions in nitrogen metabolism in the photosynthesizing shoots and destruction
processes in the brown part of gametophyte. It was established that with sufficient insolation the
nitrates content in the green vegetative part of the shoots increased, which may indicate the inhibition
of the nitrate- and nitrite reductases activity in Atrichum undulatum cells by ammonium cations. It was
investigated that in July the stability of microclimatic conditions of water-temperature regime of air
and surface soil layer in the reserved area positively influenced the processes of nitrogen plastic and
energy exchange in physiologically active and senescent parts of the shoots, as evidenced by higher
indicators of ammonium content than in recreation and felling areas. Under the influence of
insignificant insolation in the reserved area and in the recreational load zone, increasing the amount
of nitrates in green shoots is due to a decrease in the activity of nitrate-reducing enzymes. At the same
time, in the felling zone, the inactivation of nitrate- and nitrite reductases in moss cells was caused
primarily by moisture deficiency in the surface soil layer under excessive exposure to sunlight. It was
found that in the studied areas of reserve and anthropogenically modified forest ecosystems, the content
of ammonium cations and nitrate anions in the green and brown parts of shoots was mainly higher in
October, which may indicate higher physiological activity of moss in favorable conditions, primarily
of the water regime, which increased the absorption capacity of inorganic forms of biogenic element,
the processes of assimilation/dissimilation and accumulation in cells of the oxidized form of nitrogen -
-
NO3 .
Keywords: moss Atrichum undulatum, forest ecosystems, seasonal changes, microclimatic
conditions, ammonium cations, nitrate anions.