长白山原始林空间结构与落叶松毛虫虫口密度关系研究

Relationship Between Spatial Structure of Primary Forest and Population Density of Dendrolimus superans in Changbai Mountains

采用样地调查法,分析长白山国家级自然保护区原始森林空间结构与落叶松毛虫虫口密度的关系。研究表明:不同类型森林的落叶松毛虫发生程度有明显区别,云冷杉针叶林发生程度最重,其次为长白落叶松林,红松针阔叶混交林发生程度最轻;树种混交度与虫口密度呈负相关关系,混交程度越低,树种组成结构越简单,越易发生虫害;大小比数与虫口密度呈正相关关系,生长优势度低,林木抗性差的幼龄林更易受到虫害干扰;各森林类型竞争指数与虫口密度均有显著相关性,林木密度大,对空间、光照竞争激烈,自身抵抗力受到影响,易引发虫害。

The relationship between spatial structure of forest and population density of Dendrolimus superans in Changbai Mountain National Nature Reserve was analyzed through sample investigation.The results showed that the occurrence degree of Dendrolimus superans was significantly different among different types of forests,the most serious was Picea-Abies coniferous forest,followed by Larix olgensis forest,and Pinus koraiensis coniferous and broad-leaved mixed forest was the least;there was a negative correlation between the mingling degree and the population density,and the lower the mingling degree was,the forest composition and structure was simple,the more likely the pests would occur;there was a positive correlation between the neighbourhood comparison and the population density,and the sapling forest with low growth dominance and forest resistance was more susceptible to pests;the competition index of all forest types was significantly correlated with the population density,and the high density of forest which had a strong competition for space and light was easy to cause pests.