Structural and functional diversity and quantitative parameters of two-year shoot systems of pregenerative individuals of <em>Quercus robur</em> L. (Fagaceae) in different light conditions in the central part of European Russia

Based on topological characteristics and functional role in crown, diversity of the two-year shoot systems in pregenerative individuals of Q. robur L. growing in communities with different light level in southern part of Moscow region and reserve “Kaluzhskiye Zaseki” in Kaluga region have been typified. In full light conditions uniform branching, mesotonic and acrotonic two-year shoot systems with a great number of lateral twigs mainly contribute to the crown structure. In shadow conditions crown is formed basically from non-branching systems and two-year shoot systems with a small number of casually located lateral twigs. The number of nodes of the elementary shoots of different two-year system types is more constant than their internodes’ length. Branching types of two-year shoot systems have longer internodes than nonbranching ones do. In branching types of two-year shoot systems internodes become longer with the improvement of light conditions. Refs 26. Figs 3. Tables 3.