【摘要】 为了揭示林分冠层结构和林内光环境特征的关系,利用冠层分析仪(WinScanopy)对比分析了山西省太岳山马泉林场油松人工林(幼龄林和中龄林)冠层结构及林分光环境特征。结果表明:在林分密度逐步增大情况下,林分开度呈现下降趋势,总体分布范围为9.68%~16.20%;叶面积指数随林分密度的增大相应增加,总体分布范围为2.000~3.784。林分冠上总辐射分布范围为25.37~29.10 MJ/(m2·d),林下总辐射为4.22~11.07MJ/(m2·d)。林下总辐射随林分密度的增大而降低,表明林分对光辐射的截获能力随之增强。幼龄林消光系数为0.27,中龄林消光系数为0.59,中龄林林分消光能力大于幼龄林林分。林下直射是林下总辐射的主要组成部分。更多还原

【Abstract】 In this paper,the understory light characters were measured and analyzed in Pinus tabulaeformis plantation(juvenile and mid-aged stands) with WinScanopy instrument in Mt. Taiyue,Shanxi province,China. The relationship between canopy structure and light characters were also analyzed. The results indicated that stand openness(9. 68%-16. 20%) decreased,whereas the LAI in the stand(2. 000- 3. 784) increased with stand density increasing. The total PPFD above canopy ranged from 25. 37 to 29. 10 MJ /( m2·d) in P. tabulaeformis plantation. And the total PPFD under canopy deceased with the stand density ranged from 4. 22 to 11. 07 MJ /( m2·d). The light extinction ratio enlarged with the stand density increasing. And the light extinction coefficient of mid-aged stand(0. 59) was stronger than that in the juvenile stand(0. 27). The direct PPFD was the main component of total PPFD under canopy.更多还原