【摘要】 选择13年生华北落叶松人工林,设置3种修枝强度:P1(冠高比为3/4)、P2(冠高比为1/2)、P3(冠高比为2/3)。5 a后对标准木进行树干解析及节子剖析,研究修枝对华北落叶松胸径、树高、材积及节子分布的影响。结果表明:修枝对华北落叶松的生长具有促进作用,处理P2对华北落叶松胸径生长的促进作用显著大于其他处理(P<0.05),各处理间树高和材积生长量均无显著差异(P>0.05),各处理间材积的增长量从大到小次序均为P2、P1、P3;修枝处理会使节子在树干中的长度变短,减少单位面积内节子数量,从而提高木材质量。更多还原

【Abstract】 We chose 13-year Larix principis-rupprechtii plantation to set three kinds of pruning intensity of P1(the crown height percentage is 3/4),P2(the crown height percentage is 1/2),and P3(the crown height percentage is 2/3). We studied two types of effects of different pruning intensities on DBH,tree height,volume,stem form and knots through stem analysis and knot characteristics analysis on sample trees for Larch plantations after five years. Pruning on Larch plantations at growth rate have certain improvements. Processing P2 on Larch plantations DBH growth promoting effect was significantly greater than other treatment(P< 0.05). The increment of tree height and volume between the groups had no significant difference(P> 0. 05). Increase of the volume between the groups are in descending order of P2,P1,and P3. Pruning makes the length of knots shorter and reduce negative effects on the wood. With the decrease of knots,the wood quality will be improved as well.更多还原