不同林型对林下光照和辐射消减的影响

在中山市长江库区水源林市级保护区内选择4种不同的林分类型,进行每木检尺和冠层影像拍摄,处理得到林下光照因子和辐射消减因子,分析不同林型对林下光照和辐射消减的影响。结果表明:不同林型对林冠结构和林下光照影响显著,针叶林与针阔混交林的林下光照接近,林冠较差,沟谷季雨林与常绿阔叶林接近,林冠较好;辐射消减在不同林型间差异显著,针叶林和针阔混交林辐射消减较差,常绿阔叶林和沟谷季雨林辐射消减较好;林下光照与辐射消减相关性强,特别是两个林冠结构因子与辐射消减关系密切。在进行林分改造时,建议选择叶片较大较厚,冠幅大而优美的常绿阔叶树种进行更新,天然起源的林分与常绿阔叶林的林冠结构较好,有效维持了森林生态系统稳定。

Effects of different forest types on understory light and radiation reduction

Four different forest types were chosen in Changjiangkuqu water conservation forest reserve,Zhongshan, Guangdong and we got the data from the field individual measurement and canopy image for understory light factor and ra-diation reduction factor,then analyzed the effect of different forest fypes on understory light and radiation reduction which provided the data support for stand conversion and forest ecosystem stability and health maintenance. The results showed that,different canopy structure and understory light between the four forest types had significant difference,and the un-derstory light between coniferous forest and coniferous and broadleaf mixed forest were closed,which canopy structure were poorer. The understory light between evergreen broadleaf forest and ravine monsoon rain forest were closed,which canopy structure were better. There are significant difference between different forest types for radiation reduction,which had higher radiation reduction in evergreen broadleaf forest and ravine monsoon rain forest and lower in coniferous forest and coniferous and broadleaf mixed forest. There were strong correlation between understory light and radiation reduction, especially between crown canopy factors and radiation reduction factors. It is suggested that chose the evergreen broadleaf species which have big and thick leaf and large and beautiful crown to make stand improvement. Natural forest and ever-green broadleaf forest have better canopy structure,and effectively maintain the forest ecosystem stability.