中文摘要：

通过调查3种不同人为干扰强度（轻度择伐、重度择伐和皆伐）下次生林林分结构及其冠下红松生长状况，应用全天空照片法测定红松（Pinus koraiensis）顶端的透光孔隙度，分析红松当年高生长量与顶端透光环境的关系。结果表明：以蒙古栎（Quercus mongolica）为建群种的皆伐样地林冠下，林分透光较强，以杂木阔叶林为主的轻度择伐样地和重度择伐样地林冠下，林分透光较弱；对29年生红松生长起主要阻碍作用的是下木层（≥10 m）阔叶树；在透光较好的皆伐样地内，红松当年高生长量均比透光较弱的轻度择伐样地和重度择伐样地高，红松当年高生长量与顶端林分透光孔隙度显著正相关（R2=0.516，P〈0.01）；为促进辽东山区次生林向阔叶红松林正向演替，应调控红松顶端林分透光孔隙度达30%以上。

英文摘要：

To understand the effects of light regimes on the height growth of Pinus koraiensis saplings, an investigation was made under the canopies of secondary forests treated by light thinning （stand A）, heavy thinning （stand B）, and clear cut （stand C） as well as the currentyear height growth of P. koraiensis under the canopies. The canopy openness on the top of P. koraiensis saplings was measured by hemispherical photographs, and the relationship between the light regimes and the height growth increment of P. koraiensis saplings was established. The light transmittance in stand C dominated by Quercus mongolica was highers, while that in stands A and B dominated by mixed broadleaved species was lower. The major factor limiting the growth of P. koraiensis saplings was the shading of the understory broadleaved trees with a height of 10 m. The height growth increment of the P. koraiensis saplings in stand C was significantly higher than that in stands A and B. There was a significant positive relationship （R2=0.516, P〈0.01） between the currentyear height growth increment of P. koraiensis saplings and the canopy openness. It was suggested that to accelerate the positive succession of the secondary forests in eastern Liaoning Province, the canopy openness on the top of P. koraiensis saplings should be modified to more than 30%.