INTENSITY OF POLLEN DISPERSION DEPENDS ON THE STRUCTURE OF SHOOTS BEARING MALE CATKINS IN DROOPING BIRCH ( <i>BETULA PENDULA </i>ROTH.)
Drooping birch usually bears male catkins at the end of annual shoots. However, it may possess a variety of untypical catkin-bearing shoots originating from sylleptic and proleptic branching. We have found a positive correlation between outbreaks of untypical shoot formation in a drooping birch crown and its pollen production. We have demonstrated that intensive pollen dispersion of drooping birch in 2012 was its late response to anomalously hot and dry summer 2010.