【摘要】 为促进辽西半干旱地区油松人工林的可持续经营,以辽西地区辽宁省生态实验林场油松人工林为研究对象,分析带状采伐对天然更新油松幼树树冠结构的影响。2014年春季选取油松成熟林进行带状采伐,2017年冬季在采伐带及保留带内各选取不同地径大小的50株幼树进行枝条解析。测量幼树的地径、树高、冠长等林木因子,同时测量所有枝条的枝长、弦长、分枝角度、着枝深度。每株幼树每轮选取1个标准枝条,测量标准枝枝长的连年生长量。结果表明:伐带内天然更新幼树单株的平均轮数11.5,保留带内幼树活枝的平均轮数为12.1,对照区内幼树活枝的平均轮数为12.8。方差分析结果表明采伐带、保留带与对照区内油松幼树单株活枝轮数差异不显著(p>0.05)。在实施带状采伐后,采伐带内幼树单株每轮平均枝条数量为2.4,保留带内单株每轮平均枝条数量2,采伐带内单株每轮枝条数量显著大于保留带(p<0.05)。采伐带内枝条的分枝角度从树冠上部至下部变化较大,保留带内则变化相对较小,且保留带各轮枝条分枝角度总体上大于采伐带。采伐带内枝条的平均生长量为16.1cm,保留带的平均生长量为11.7cm,差异显著(p<0.05)。采伐带内天然更新油松幼树树冠形状的平均拐点为0.66,保留带平均拐点为0.73,对照区的幼树树冠的平均拐点为0.74,保留带内幼树的拐点显著大于采伐带,保留带与对照区之间的拐点差异不显著(p>0.05)。研究结果可为制定科学合理的森林经营方案以促进油松人工林天然更新奠定基础。更多还原

【Abstract】 The present study toke the Pinus tabulaeformis plantation from Liaoning Ecological Experimental Forest Farm in west part of Liaoning Province as the subject, the effect of strip clear-cut on the crown structure of natural regeneration Pinus tabulaeformis sapling was studied. The strip clear-cut experiment for the mature Pinus tabulaeformis plantation was conducted in 2014, and a total of50, 50, and 30 saplings from clear-cut strip, uncut strip and comparison area were selected and the branch analysis was conducted.The ground diameter, total tree height, crown length for the saplings and branch length, branch chord, branch angle and depth into the crown of interest for the branches were measured. One sample branch from each whorl of the sapling was selected to measure the annual branch length growth. The results showed that there was no significant difference for the whorl numbers per saplings among the clear-cut strip, uncut strip and comparison area(p>0.05). The mean number of branch of each whorl for the saplings from clear-cut strip, uncut strip were 2.4 and 2, respectively, and the clear-cut strip was significantly larger than uncut strip(p<0.05). The number of branch newly grown from clear-cut strip was larger than uncut strip after the conduction of strip clear-cut experiment. The branch angle for the saplings from clear-cut strip showed large variation from the top of crown to the bottom in contrast to the uncut strip.The branch angles of the branch from each whorl for the uncut strip were larger than the clear-cut strip. The mean increment for the branch was 16.1 cm for clear-cut strip, and 11.7 cm for the uncut strip with significant difference(p<0.05). The mean inflection point of crown shape of natural regeneration Pinus tabulaeformis sapling in the clear-cut strip is 0.66, and that in the uncut strip is 0.73. The inflection point of saplings in the uncut strip is significantly larger than that in the clear-cuts strip. The present study provided reference for the reasonable forest management decision making to improve the natural regeneration for the Pinus tabulaeformis plantation.更多还原