摘要
杉木林密度间伐试验历经 1 8年的定位试验研究 ,其结果表明 :(1 )同一立地指数级 ,不同初植密度的林分 ,当某一密度的林分经间伐后同另外一个密度基本相同未间伐的林分比较 ,两者优势木高、平均木高无明显差异 ;两者胸径差异明显 ,即间伐的林分小于未间伐的林分 ;两者立木蓄积 ,间伐的低于未间伐的 ;间伐林分总蓄积量 (立木蓄积 +间伐蓄积 )高于未间伐的蓄积。初植密度不同的林分 ,间伐后与未间伐林分的总蓄积量百分比 ,其比值 ,初植密度大的大于初植密度小的 ;间伐林分的枝下高一般高于未间伐林分的枝下高 ,1 6年前影响明显 ;间伐林分的冠幅一般小于未间伐林分的冠幅 ,1 1～ 1 6年时差异明显。 (2 )立地指数级不同 ,初植密度基本相同的林分 ,间伐与未间伐林分的总蓄积量百分比 。
According to 18 years located study of density and thinning experiments of Chinese fir stands,we can get some results as followings:1.At the same site index class,comparing the unthinned stand with the thinned stand which keeps the same density with the unthinned stand after thinning,their average tree height and dominant tree height have no evident difference. The diameter at breast height( DBH ) of thinned stand is much lower than that of unthinned stand. The standing stock of thinned stand is lower than that of unthinnned stand.The total volume (standing stock+thinned tree volume) of thinned stand is higher than that of unthinned stand. The ratio of total volume of thinned stand with high primary density to unthinned stand is higher than that of thinned stand with low primary density to unthinnned stand.The tree height under the first branch of thinned stand is higher than that of unthinned stand,and it is especially evident when the stand is less than 16 years old.The crown diameter of thinned stand is lower than that of unthinned stand,and the difference is remarkable when the stand is 11～16 years old.2.With the same primary density,the ratio of total volume of thinned stand to that of unthinned stand at the high site index class is higher than that at the low site index class.
出处
《林业科学》
CAS
CSCD
北大核心
2000年第z01期86-89,共4页
Scientia Silvae Sinicae
基金
国家"九五"攻关专题!杉木建筑材树种遗传改良及培育技术研究的一部分
