Karelian birch responsiveness to nitrogen treatment

The hypothesis that the formation of the figured pattern in Karelian birch wood is related to excess sucrose in the conducting phloem and cambial zone of the trunk highlights the significance of soil fertility in this process. The present studies were conducted on Karelian birch plants grown under two different regimes of nitrogen treatment (0 and 40 g N tree"1). The fertilization resulted in an increase in leaf area and the above ground to below ground biomass ratio. The development of water stress, probably due to the combined effect of nitrogen treatment and atmospheric drought, is prevented through a decrease in stomatal conductance and transpiration rate. At the same time, there is a decrease in the rate of photosynthesis, which leads to a decrease in the amount of produced sucrose. In this regard, we assume that the nitrogen treatment of the soil will have a negative impact on figured wood formation in Karelian birch.