Aboveground biomass partitioning and crown architecture of Eucalyptus nitens following green pruning

The effects of green pruning on aboveground biomass partitioning and crown architecture were explored in a 3-year-old Eucalyptus nitens (Deane and Maiden) Maiden plantation. Responses were measured in five height zones and three foliage age classes over a 20-month period following removal of 0, 50, or 70% of the green crown length. Development of foliage in the upper crowns of 50%-pruned trees was faster and total leaf area at the end of the experiment was greater than in unpruned trees. Leaf area development of 70%-pruned trees was similar to that of unpruned trees. Larger apical leaves, with a lower specific leaf area (SLA), developed following 50% pruning. However, 70% pruning resulted in smaller leaves, and SLA increased in some crown positions. Pruning reduced branch diameter and length in the upper crowns. However, branches of 50%-pruned trees had an increased ratio of foliage to wood dry mass. These responses to green pruning may have increased the carbon-fixing capacity and the efficiency of carbon utilisation of the remaining crown. Following 50% pruning, responses were sufficient to maintain stem dry mass increment at a level similar to that of unpruned trees. However, following 70% pruning, stem and branch dry mass increment was reduced.