辽东栎植冠的构型分析

对辽东栎 ( Quercus liaotungensis)个体发育中不同阶段的植冠构型进行统计分析 ,结果发现 :构型转变主要表现在分枝格局上 ,除枝、叶方位角和叶倾角外 ,分枝率、枝长和枝倾角都发生过显著改变。不同阶段构型分析的比较表明 :1 )幼苗阶段 ,高生长显著 ,枝条伸长较快 ,但分枝率低 ;2 )幼树阶段 ,分枝率显著小于成株阶段 ,但上层枝条的平均枝倾角大于其它两阶段 ,上层枝条的长度也大于成株阶段 ;3)成株阶段 ,冠幅迅速扩展 ,分枝率较前两时期显著增加 ,同时顶端优势减弱 ,引起休眠芽萌动和萌生苗的发生。而枝的转向是植物个体发育过程中构型调整的直接证明。这些都说明了辽东栎在生活史的不同阶段 ,因为所处的微生境和所面临的威胁都各不相同 ,在构型表达上也有不同对策。

ARCHITECTURAL ANALYSIS OF CROWN GEOMETRY IN QUERCUS LIAOTUNGENSIS

Architectural analyses were made in different developmental stages of Quercus liaotungensis. The result is that architectural transition,mainly characterized by the changes of branch pattern,and bifurcation ratio,branch angle to horizon and branch length in upper layer,varied significantly in different developmental stage.The architectural comparison shows that:1)Seedlings grew quickly for abundant nutrient supply,and their branches extended rapidly with low bifurcation ratio;2)in sapling stage,both branch angle to horizon and branch length were larger than those in mature tree stage,and vice verse for bifurcation ratio;3)in mature tree stage,crown enlarged rapidly.Bifurcation ratio was much larger than those in the previous two stages,Dormant buds released and seedlings sprouted with apical dominance declined.Moreover,branch reorientation was a direct demonstration for architecture modulation.All above suggest that Quercus liaotungensis has different strategies in architecture to deal with varied micro environment and oppression.