小陇山日本落叶松中龄纯林形质最优郁闭度

Optimal Crown Density of Middle Age Pure Larix kaempferi Forest in Xiaolongshan

为有效提升小陇山林区日本落叶松中龄纯林质量,确定最优间伐强度,在小陇山林区日本落叶松纯林内共设置12块固定试验样地,分别进行重度、中度、轻度间伐,测定15项指标,通过专家评分,运用层次分析法建立林木形质评价体系进行综合评价。结果表明中度间伐林木形质综合评价得分最高,轻度间伐次之,对照得分最低。试验证明,小陇山林区日本落叶松30-40 a中龄纯林中度间伐效果最好,伐后密度1 000-1 200株/hm^(2)、郁闭度0.7时,林木形质最优;重度间伐会降低干形质量。

In order to effectively improve the quality of middle-aged pure forest in Xiaolongshan forest region,the optimal crown density was determined.A total of 12 fixed test plots were set up in the pure forest of Larix kaempferi in Xiaolongshan forest area,severe thinning,moderate thinning and mild thinning were carried out,15 indexes were measured,and the comprehensive evaluation system of tree shape quality was established by using analytic hierarchy process(AHP)and expert score,which showed that the score of comprehensive evaluation of tree shape quality was the highest in moderate thinning,followed by light thinning,and the lowest in control.The results showed that the best thinning effect was 30 to 40 years old pure forest of Larix kaempferi in Xiaolongshan forest area.The forest shape was the best when the density was 1000 to 1200 trees/hm^(2) and the crown density was 0.7,besides,heavy thinning can reduce dry shape quality.