Growth and biomass partitioning response of northern red oak genotypes to shading and grass root competition

First-year biomass, biomass relative growth rate, and biomass partitioning among organs were compared among 8 open-pollinated families of Quercus rubra under crossed levels of light intensity (100% and 37% full sun) and grass root competition (presence and absence of Poa pratensis). Results suggest that families with superior juvenile growth rate under competition-free conditions will also have superior growth rate under at least some conditions of shading and root competition. Biomass partitioning to leaf area, and to shoot weight relative to root weight declined during seedling. development. Both shoot-root ratio and leaf area ratio were greater in shaded compared to full sun environments, while the presence of grass root competition had an opposite effect on both ratios. -from Authors