摘要
在6种不同的林分类型中设置20 m×30 m的标准地,对林木竞争指数与钝鞘中脉叶蜂虫口密度的相关性进行研究的结果表明:钝鞘中脉叶蜂虫口密度与相对胸径、相对树高、相对冠幅和相对断面积均呈正相关关系,其相关性强弱依次为:相对冠幅、相对胸径、相对断面积、相对树高;与Hegyi指数、基于交角的林木竞争指数(胸径大小比数)呈负相关关系,与基于交角的林木竞争指数(树高大小比数)、大小比数不存在相关关系;与生长空间指数呈正相关关系,与树冠伸展度、树冠冠长率、树冠圆满度和树冠投影比无相关性。钝鞘中脉叶蜂虫口密度与反映林木个体与群体水平的林木竞争指数的相关性强于反映林木个体与相邻木水平指数的相关性,与反映林木个体特征指数的相关性最差;寄主在林分中的优势地位越高,虫口密度越大;在森林经营中,可针对不同的林种类型,选择一种相关性强且符合经营目的的竞争指数,作为利用营林措施防控钝鞘中脉叶蜂的依据。
A standard plot of 20m×30m was set up in six different stand types,and the correlation between tree competition index and population density of Mesoneura truncatatheca was investigated.The results showed that population density of Mesoneura truncatatheca was positively correlated with relative diameter at breast height,relative tree height,relative crown with comprehensive weight and relative cross-sectional area,and the correlations were in order of strength:relative crown with comprehensive weight,relative diameter at breast,relative cross-sectional area and relative tree height;negatively correlated with Hegyi index and cross-angle-based stand competition index(neighborhood comparison index of diameter at breast height),and not correlated with cross-angle-based stand competition index(tree height to size ratio) and size ratio.There was a positive correlation with growth space index and no correlation with crown extension,crown length ratio,crown completeness and crown projection ratio.The correlation between the population density of Mesoneura truncatatheca and the tree competition index reflecting the individual and group level of the stand was stronger than the correlation reflecting the individual and adjacent wood level index,and the correlation with the index reflecting the individual characteristics of the stand was the worst.The higher the dominance of the host in the stand,the higher the density of the insect population;in forest management,a competition index with strong correlation and consistent with the management purpose can be selected for different forest species types as a basis for using forestry measures to prevent and control Mesoneura truncatatheca.
作者
牟顺泰
张永晖
魏小虎
莫晶
李琼
王林浩
MU Shuntai;ZHANG Yonghui;WEI Xiaohu;MO Jing;LI Qiong;WANG Linhao(Forestry pest Control and Quarantine Station,Xiaolongshan,Gansu Tianshui 741020)
出处
《林业科技》
2023年第6期35-40,共6页
Forestry Science & Technology
关键词
钝鞘中脉叶蜂
虫口密度
林木竞争指数
Mesoneura truncatatheca
population density
tree competition index
