关帝山云杉次生林冠层结构对天然更新的影响

Effects of canopy structure on natural regeneration of Picea asperata secondary forest in Guandi Mountain

冠层结构和林下光环境对天然更新苗的分布和生长具有重要的作用。本研究以关帝山云杉次生林天然更新苗为对象,利用单因素方差分析和泊松相关性检验,分析冠层结构对天然更新苗的影响。结果表明:在林冠开度(CO)为19.5%~24.5%、林下散射光指数为4~5时天然更新株数最多;最适的CO、林下直射光和林下总光照表现为幼苗大于幼树,而最适叶面积指数则幼苗小于幼树;冠层结构及林下光照对于幼苗的生长相关性不显著。幼苗和幼树对于林下光环境有着不同的适应区间,不同密度的更新苗样地间叶面积指数和林下光照存在显著差异,研究结果为理解该地区林分天然更新提供科学依据。

Canopy structure and understory light environment play an important role in the distribution and growth of naturally regenerated seedlings.Here,we analyzed the effects of canopy structure on naturally regenerated seedlings of Picea asperata secondary forest in Guandi Mountain by one-way ANOVA and Poisson correlation test.The number of naturally regenerated trees was the largest when the canopy openness(CO)was 19.5%-24.5%and the transmitted diffuse solar radiation index was 4-5.The optimum CO,transmitted direct solar radiation,and transmitted total solar radiation of seedlings were higher than those of saplings,while the optimal leaf area index(LAI)was lower than that of the saplings.Canopy structure and understory light were not significantly related to the growth of seedlings.Seedlings and saplings had different adaptation ranges to the understory light environment.There were significant differences in LAI and light intensity among the plots with different densities of regenerated seedlings.Our results provide a theoretical basis for understanding the natural regeneration of forests in this area.