西藏东南部典型林草交错地带不同植被地表节肢动物多样性研究

Diversity of arthropods on different vegetation types in typical forest grass ecotone of Southeast Tibet

【目的】了解西藏东南部不同植被类型对地表节肢动物群落结构及多样性的影响。【方法】采用陷阱诱捕法于2018年5~9月对高山栎灌丛、高山栎灌丛林牧交错地带(林牧交错地带)、天然草地、人工种植草地4种典型植被类型进行地表节肢动物调查,分析其相对多度、类群丰富度、Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson优势度及相似性指数Sorensen和Cody。【结果】1)西藏东南部不同植被群落之间地表节肢动物群落组成和数量有较大差异。天然草地具有最多的节肢动物科类群数,地表节肢动物有77科,动物数占全部采集样数的32.36%;其次是林牧交错地带,地表节肢动物有75科,动物数占全部采集样数的32.77%;类群相对较少的是高山栎灌丛和人工草地,分别为59和55科,动物数分别占全部采集样数的9.27%和25.60%;高山栎灌丛采集到的动物数量最少,且不同类群间差异较大。2)类群丰富度天然草地最高,人工草地最低;Shannon-Wiener多样性指数天然草地最高,高山栎灌丛最低;Pielou均匀度指数高山栎灌丛最低,天然草地最高;Simpson优势度指数高山栎灌丛最高,林牧交错地带最低。3)Sorensen相似性指数最高值出现在高山栎灌丛与林牧交错地带之间,高山栎灌丛与人工草地的Sorensen相似性指数和人工草地与林牧交错地带的接近,高山栎灌丛与林牧交错地带的Sorensen相似性指数和人工草地与天然草地的接近。高山栎灌丛与天然草地的Cody相似性指数最高,其次是林牧交错地带与天然草地;高山栎灌丛与林牧交错地带、人工草地与天然草地的Cody指数最小。【结论】西藏东南部植被类型、环境、干扰程度均对地表节肢动物有较大影响。林牧交错地带是高山栎灌丛与天然草地之间的过渡地带,天然草地是林牧交错地带与人工草地之间的过渡地带,但在演替过程中具有连续性。

【Objective】This study aimed to understand the influence of different vegetation types on community structure and diversity of surface arthropods in southeast Tibet.【Method】From May to September in 2018,four typical vegetation types of Quercus aquifolioide shrubs,forest and animal husbandry,natural grassland and artificially grassland were investigated by the method of trapping.The relative abundance,group richness,Shannon-Wiener diversity index,Pielou evenness index,Simpson dominance index and similarity indexes(Cody and Sorensen)were analyzed.【Result】1)The composition and quantity of arthropod community in different vegetation communities were quite different.The natural grassland had the largest number of arthropod families,including 77 families of surface arthropods and accounting for 32.36%of all samples collected.The second was the crisscross area of forest and animal husbandry,including 75 families and accounting for 32.77%of all samples collected.The relatively small groups were Q.aquifolioide shrubs and artificial grassland,with 59 and 55 families and accounting for 9.27%and 25.60%of the total,respectively.The number of Q.aquifolioide shrubs collected was the least with great differences among different groups.2)The group richness was the highest in natural grassland and the lowest in artificial grassland.Shannon-Wiener diversity index was the highest in natural grassland and the lowest in Q.aquifolioide shrubs.Pielou uniformity index was the lowest in Q.aquifolioide shrubs and the highest in natural grassland,and Simpson dominance index was the highest in Q.aquifolioide shrubs and the lowest in forest-pastoral zone.3)The highest value of Sorensen similarity index was between Q.aquifolioide shrubs and forest-pastoral transition zone.The Sorensen similarity index of Q.aquifolioide shrubs and artificial grassland was close to that of artificial grassland and forest-pastoral zone.The Sorensen similarity index of Q.aquifolioide shrubs and forest-pastoral zone was close to that of artificial grassland and natural grassland.The Cody index between Q.aquifolioide shrubs and natural grassland was the highest,followed by forest-pastoral transition zone and natural grassland.Q.aquifolioide shrubs and forest-pastoral transition zone,artificial grassland and natural grassland had the smallest Cody index.【Conclusion】The surface arthropods were greatly influenced by vegetation types,environmental changes and disturbance degrees in southeastern Tibet.Forest-pastoral zone was the transition zone between Q.aquifolioide shrubs and natural grassland,and natural grassland was the transitional zone between forest-pastoral zone and artificial grassland,but there was continuity in the process of succession.