临海市松材线虫病松林不同除治方式的群落自然演替特征

Natural Succession and Characteristics of Pine Plantation with Two Treatments for Bursaphelenchus xylophilus in Linhai of Zhejiang Province

以浙江省临海市感染松材线虫病后松树皆伐和择伐两种除治方式的试验林为研究对象,采用样地调查的方法记录试验样地植被种类、乔木树高与胸径以及乔木幼树、灌木与草本植物的覆盖度,分析除治迹地自然演替林分的结构、优势种和演替特征。结果显示:(1)皆伐样地乔木层、下木层与灌草层共有植物24种,择伐样地共有42种,两类样地的乔木层树高均呈近正态分布,胸径呈“J型分布”。(2)皆伐样地马尔可夫模型(Margalef)指数4.037,择伐样地6.761。林分结构呈类似自然林的聚集分布,生物多样性显著高于原马尾松林。(3)皆伐样地已演替为枫香和朴树为主的落叶阔叶林,马尾松消失,下木层优势种为朴树,预测该林分将长期为落叶阔叶林;择伐样地马尾松仍为乔木层的优势种,伴生枫香和樟树等阔叶树种,下木层优势种为白栎,预测现存的针阔混交林将向常绿落叶阔叶混交林过渡。基于松材线虫病除治迹地林分自然恢复慢、林相残破、生态经济价值低等问题,提出需依据林分演替方向选择彩色珍贵树种进行补植更新措施。

This study investigated the plant species in pine plantation with clear cutting and selective cutting for Bursaphelenchus xylophilus treatment in Linhai manucipality.We used the sample plot inventory method to measure the tree height and DBH of arbor,simultaneously recorded the coverage of arbor sapling,shrubs and herbs in two study plots.Based on the stand structure models,we analyzed the forest structure,dominant species and natural succession and characteristics of the two plots.The results showed that,include the tree layer,undergrowth layer,herbaceous layer and lianas,there were 24 plant species in the clear-cutting site and 42 plant species in the selective-cutting site.The tree height of the arbor layer in the two plots all showed nearly normal distribution,and the DBH showed“J-shaped distribution”.The Margalef index of the clear-cutting plot was 4.037,and the Margalef index of the selective-cutting plot was 6.761.The stand structure of the two plots were all belonged to the natural forest and the two plots’biodiversity were all higher than that of pure Pinus massoniana forest.The dominant species in the clear-cut plot is Liquidambar formosana and Celtis sinensis,there is no P.massoniana in it.The clear-cutting plot had succeeded as a deciduous broad-leaved forest.Based on the dominant species of clear-cutting renewal layer,we speculate that this plot will maintain the state of deciduous broad-leaved forest for a long time in the future.Different from clear-cutting plot,the dominant species in the selective-cutting plot was P.massoniana,the associated species were Cinnamomum camphora and L.formosana.The dominant species in the selective-cutting renewal layer was Quercus fabri,therefore,we speculate that in the future this plot will gradually change from coniferous and broad-leaved mixed forest to evergreen and deciduous broad-leaved mixed forest.Combined with the results,the natural succession results of stands with different treatment methods were different.However,there are some defects in the two kinds of plots,such as slow natural recovery,broken forest appearance,serious soil waste and so on.Consequently,it is necessary to apply the human intervention and programming based on different succession states in pine wood nematode treatment slash.