The influence of sexual dimorphism on the phenotypical properties of poplar

Abstract The influence of sexual dimorphism on commercial-biological traits of the most widespread poplar of the world Populus tremula L. in the Central forest-steppe of the European territory of Russia was studied. The analysis was made of the distribution of male and female clones in general, the effects of humidity, the richness of the soil, and surrounding vegetation on their productive capacity as well as core rot damage. The study presents survey results of 620 aspen plots spread out over an area of 823 hectares as well as more detailed data obtained from 3 pairs of test plots in which the indicators of male and female aspen stands were compared under identical or similar conditions. The study showed that the area of male aspen in the studied region is 4.5 times larger than that of females. The former prevail in drier and less fertile conditions while females gravitate towards more favorable growing conditions. The comparison of the productive capacity of male and female clones of the same age class, growing in identical or similar growing conditions showed that the height, diameter, and volume of the trunks were higher in male trees. Female aspen trees were less affected by core rot in the best conditions of growth, and male ones were more resistant at the worse ones.