Produktywność biomasy nadziemnej i podziemnej w doświadczeniu proweniencyjno-rodowym z dębem szypułkowym

The biomass productivity of individual trees at age 14 years was investigated in the experiment with 8 provenances and 186 half−sib families of pedunculate oak (Quercus robur L.). The aim of the study was to develop allometric equations and estimate heritability of tree biomass. We sampled 28 model trees and measured dry mass of their components, including roots (on 14 trees). A decreasing share of aboveground biomass was allocated to stems, and an increasing share to branches and foliage with increasing tree size. Also a decreasing share of total tree biomass was found in roots with increasing tree dimensions. Allometric equations involving diameter at breast height in combination with tree height were developed to model biomass of all components and whole tree. We used those equations to estimate tree biomass on the subset of research area, involving all provenances and 180 half−sib families. Heritability coefficients for tree biomass were the greatest for provenances (0.84), average for families (0.58) and the lowest for individual trees (0.18). However, estimates of family heritability varied by provenance (from 0.18 to 0.74). These findings suggest that the most efficient strategy for improvement of productivity in pedunculate oak would be selection of provenances and families within provenances.