摘要
通过对天山云杉林中 30个林冠空隙的调查 ,研究了新疆天山云杉林林冠空隙的基本特征和影响林冠空隙内幼苗更新的因子 .结果表明 ,本研究范围内 ,天山云杉林扩展林冠空隙 (EG)的面积在 5 0 .81～ 2 98.0 5m2 之间 ,其中以 4 0～ 1 6 0m2 所占比例较大 ;实际林冠空隙 (CG)的面积大多在 1 1 .37～ 1 83.39m2 之间 ,其中以小于 80m2 所占比例较大 ;CG EG值大多在 0 .4～ 0 .6之间 ,大多数林隙的形状近似于圆形 ,都接近于 1 ;林冠空隙有 1 0种形成方式 ,其中以伐倒和伐倒 +掘根风倒的方式最多 ;林冠空隙开敞度大多分布在 0 .4～ 1 .5之间 ,当开敞度为 0 .6 8时 ,幼苗更新株数最多能达到 2 76 75株 hm2 ;
Through field investigation of 30 gaps in Picea shrenkiana var. tianschanica forests in Practice Forestry Center of Xinjiang Agricultural University in 1999, this paper analyzes gap characteristics and the factors influencing the regeneration of seedlings in gaps. The results indicated that, in Picea shrenkiana var. tianschanica forests, the size of extended gaps (EG) ranged from 50.81 to 298.05 m 2, and a large proportion of extended gaps were in the size of 40～160 m 2; the size of canopy gap (CG) varied from 11.37 to 183.39 m 2, and a large proportion of canopy gaps were in the size of less than 80 m 2; the ratio of CG to EG differed from 0.4 to 0.6; shape index of most EG and CG were close to 1; there were ten kinds of forming manners for the gaps, among which the hew down and hew down +windfall with root stumping were common; the opening degree ranged from 0.4 to 1.5, and when the value of opening degree was 0.68, the number of regeneration seedlings reached maximum with 27 675 per hectare; slope aspect and gradient had positive effects on the regeneration of seedlings.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2004年第2期37-42,共6页
Journal of Beijing Forestry University
基金
国家自然科学基金资助项目 ( 3 9660 0 66
3 9960 0 63 )
教育部优秀青年教师资助计划项目共同资助
关键词
天山云杉林
林冠干扰
林冠空隙
Picea shrenkiana var. tianschanica forest, canopy disturbance, canopy gap
