择伐作业对常绿阔叶林乔木层树种结构及物种多样性的影响

Effects of selective cutting of different intensities on the tree layer structure and species diversity of evergreen broadleaved forest

研究4种不同强度择伐作业(弱度13.0%、中度29.1%、强度45.8%和极强度67.1%)对常绿阔叶林林分结构及乔木层物种多样性的影响结果表明,轻度与中度择伐对林分结构的影响较小,原林分乔木层优势树种的地位仍保持甚至略有提高;而强度择伐和极强度择伐则引起林分结构一定的变化,一些优势树种的地位削弱,而另一些树种的优势地位上升。但采伐作业不利于常绿阔叶林物种多样性的发展,尤其是林冠强度破坏对物种多样性的影响最大,而轻度与中度择伐作业有利于原有物种保持与恢复,这可能与不同强度择伐作业引起林地光照条件、温度和湿度等环境因子的不同变化有关。

The effects of selective cutting of different intensity on the tree layer structure and species diversity of evergreen broadleaved forest(low intensity,13.0%;middle intensity,29.1%;high intensity,45.8%;over-high intensity,(67.1%)) were surveyed and analyzed.The results show that the selective cutting of low and middle intensities caused a light variation to the tree layer structure,but the selective cutting of high and over-high intensities caused changes of the tree layer structure to some extent.The cutting operation results in adverse influences on the development of tree layer species diversity of evergreen broadleaved forest,particularly the serious damage to the forest canopy caused by selective cutting of high intensity.But the rational selective cutting benefits the restoration and maintenance of species during a long time,which may result from the different variations of such environmental factors as sunlight,temperature and humidity,etc caused by cutting operation.