Quantifying branch, crown and bole development in Populus tremuloides Michx. from north-eastern British Columbia

摘要

Trembling aspen (Populus tremuloides Michx.) from 14 aspen stands ranging in age from 5 to 142 years were destructively sampled to provide branch, crown and bole growth information. Analysis of crown development processes such as branch angle, branch extensional growth, branch crookedness and annual height growth suggested a significant increase in relative branch growth with height and age which was linked to the temporal decline of height growth. Crown class dependent crown length (%) and crown area relationships were observed indicating crown size followed the sequence: open grown trees>dominants>suppressed trees. A significant shift in crown development from vertical to lateral crown expansion was observed as aspen mature.