Abstract:

Leaf area (LA) as an essential part of crown structure affects both the growth of forests and protective effects of shelterbelt. The variation in leaf area with position in the crown and with 4 ranks branch were investigated from 4-row 9-year-old Populus × euramericana (Dode) Guinier CL. ‘zhonglin 46’ shelterbelts in eastern plain of Henan. Allometric equations describing the leaf area of the entire crown were developed, and used to estimate shelterbelts leaf area. The results showed that leaf area were significantly influenced by the position in the crown. Leaf area in the middle was significantly higher than that in the upper and the lower of the crown, and increased significantly from the interior to the exterior of the crown. There were significant differences among branch classes. Leaf area from 5 ranks branch followed the sequence: secondary shoots>third shoots>primary branch>fourth shoots>fifth shoots. Stem diameter at breast height (DBH), tree height (H), crown length (CL) and their compound indexes were all reliable predictors of leaf area at the tree level. In contrast, it was more convenient to apply DBH to predict leaf area at the tree-level.