Polyvariance of the habitus of virginal and young reproductive individuals of Quercus robur L. (Fagaceae) in phytocenoses of the Upper and Middle Oka river

From the perspective of the modular concept the variability of crown architecture of virginal and young reproductive individuals of Quercus robur L. has been researched. The individuals grow in phytocenoses of the Upper and Middle Oka river. The plant communities are subdivided into three groups accordingly to their light level (% of the full light): mesophytic meadows (100%), grass birch stands and pineries with small gaps (35-55%), closed canopy pineries (15-30%). The total amount of individuals is 210. In each individual, the configuration, growth and branching of the axes of the main structural units of the crown are considered. Meanings of quantitative parameters of shoot systems were selectively measured. Four architectural types have been distinguished: "Мeadow", "Мargin", "Forest 1", "Forest 2". The individuals of the meadow and margin types grow within the 1st and 2nd light level group communities respectively. The individuals of the forest types grow within the 3rd light level group community. In a series from the meadow type to the forest types ramification of biennial shoot systems simplifies while shape and structure of the branches from the trunk and trunk itself get more complex. Thus we figured out that Q. robur has a significant polyvariance of shoot systems, which leads to formation of qualitatively different types of habitus.