关帝山不同海拔天然次生杨桦林地表昆虫群落结构及多样性特征分析

Above-Ground Insect Community Structure and Diversity in Natural Secondary Poplar Birch Forest at Different Altitudes in Guandi Mountain

地表昆虫作为森林群落生态系统的重要组成部分,能够加快凋落物分解及土壤生态学过程。为了解关帝山林区地表昆虫群落组成及多样性特征,探讨影响其空间格局分布的环境因子,在关帝山林区典型的天然次生阔叶林生态系统——杨-桦混交林中,从海拔1 600~2 200 m梯度范围设置4个生境,于2022年的7-8月采用巴氏罐诱法对林下地表昆虫进行2次系统的调查,对不同海拔地表昆虫多样性指数进行单因素方差分析,并利用冗余分析来确定环境因子对地表昆虫多样性的影响。结果表明,1)采集2 449头地表昆虫,隶属于7目30科64种,其中,步甲科和蚁科为优势物种。2)不同海拔地表昆虫群落组成差异明显,其个体数和物种数均随海拔高度的升高呈下降的趋势,不同海拔梯度间地表昆虫群落的相似性系数显示相邻2个海拔之间物种的相似性较高。3)低海拔段的Shannon多样性指数、Pielou均匀度指数和Margalef丰富度指较高,各海拔Pielou均匀度指数无显著差异。4)Pearson相关系数分析表明,土壤的温度、水分及孔隙度是影响地表昆虫物种多样性的主要环境因子;冗余分析也进一步确定温度是影响地表昆虫群落分布最主要的因素。研究结果为关帝山生态系统研究进行重要补充,也为关帝山林区地表昆虫多样性保护提供一定的理论基础。

As an important component of forest community ecosystem,above-ground insects can accelerate litter decomposition and soil ecological processes.In order to understand the composition and diversity of insect communities on the ground and to explore the environmental factors affecting the spatial distribution pattern of insect communities in the Guandi Mountain forest region,the study was conducted in the poplarbirch forest,a typical broad-leaved forest ecosystem in the region,four habitats ranging from 1600 to 2200 m above altitude level were set up.Two systematic surveys of above-ground insects were carried out in July-August 2022 by means of Babbitt pot traps,single factor analysis of variance(ANOVA)and redundancy analysis were used to determine the impact of environmental factors on insect diversity at different altitudes.The results showed that 1)a total of 2449 insects were collected,belonging to 30 families and 64 species of 7 orders.Among them,Carabidae and Formicidae were the dominant species.2) The compositionof above-ground insects of different altitudes was obviously different,and the number of individuals andspecies decreased with the elevation,the similarity coefficient of above-ground insects communities at differentaltitudes showed that the species similarity between adjacent two altitudes was high.3) The Shannondiversity index,Pielou evenness index and Margalef richness index were higher in the low altitude,butthere was no significant difference in Pielou evenness index among different altitudes.4) Pearson correlationcoefficient analysis showed that soil temperature,water and porosity were the main environmental factorsaffecting insect species diversity.Further redundancy analysis showed that temperature was the mostimportant factor affecting the distribution of insect communities on the ground.This study is an importantsupplement to the study on the ecosystem of the Guandi Mountain and provides a theoretical basis for theprotection of above-ground insects.