毛竹竹秆碳密度的垂直分布格局

Vertical Distribution Pattern of Carbon Density in the Culms of Phyllostachys edulis

采用＂逐节取样＂法,对1、3和7年生毛竹秆竹节和节间的碳密度进行了测定。结果发现：1）竹秆竹节和节间的碳密度（g/g）分别介于0.4506-0.4757、0.4522-0.4769,竹节和节间碳密度都随竹秆高度升高而增加。1年生竹秆基部碳密度增加较慢,梢部碳密度上升较快。3年生和7年生竹秆碳密度基部和中部上升较快,梢部上升慢。1年生竹秆梢部节间的碳密度高于节的碳密度,基部节碳密度低于节间碳密度。3年生竹秆节间的碳密度均略高于节碳密度,7年生毛竹竹秆中部和梢部节间碳密度明显高于节碳密度。2）竹秆基部和中部碳密度都随竹龄的增加而升高,竹秆碳密度从1年生到3年生阶段的变化较大,而从3年生到7年生阶段的变化较小。3）按相对节数的分段方法将竹秆分成5段能得到较精确的碳密度变化趋势。

By method＂node sampling＂,the carbon density of both node and internode of Phyllostachys edulis culm among 1-year old,3 years old and 7 years old were detected and studied.The result showed that：（1） The carbon density（g/g） of node and internode lied respectively between 0.4506～0.4757,0.4522～0.4769,and it increased as the height went high.The carbon density of 1-year old clum increased more slowly at lower part,and increased rapidly at upper part.On the contrary,the carbon density of lower part and middle part increased rapidly for both 3 years old and 7 years old,and slowly at upper part.For 1-year old clum,the carbon density of node was higher than that of internode at lower part,but lower in upper part.The carbon density of internode higher slightly than that of node for 3 years old,and significantly for 7 years old in middle part and in upper part especially.（2） The carbon density of clum at lower part and middle part increased as ages went high.The carbon density changed greatly during the period of 1-year old to 3 years old,and changed weekly during the period of 3 years old to 7 years old.（3） The accurate trend obtained from dividing clum into 5 segmentations by relative node number.