Structural Changes in the Vascular Cambium and Secondary Xylem Elements in the Stem of $Alnus hirsuta(S_{PACH}) Rupr.$. in Relation to the Girth of Tree.

물오리나무$[Alnus hirsuta(S_{PACH}) Rupr.]$ 줄기의 둘레에 따른 유관속형성층과 이기목부의 구조적 변화

The structural changes in the vascular cambium and secondary xylem Alnus hirsuta (SPACH) Rupr. have been investigated in relation to the girth of the tree. The fusiform initials gain a gradual size increase and later remain more or less constant in their length and width. The width of the ray initials remain constant but their heights gradually increase before becoming almost constant. Xylem elements undergo considerable changes in their dimension with the growing girth of the tree and their trends of structural changes are the same as those of cambium.