干旱绿洲区不同生长年限枸杞林地面节肢动物群落分布特征

The Distribution of Ground-active Arthropod Communities in Aged Lycium barbarum Plantations in Arid Oasis Region

选择干旱绿洲区宁夏中宁县1、3、5、8和10年生枸杞(Lycium barbarum)林为研究对象,以农田为对照,利用陷阱诱捕法调查不同样地地面节肢动物群落分布特征及其与环境因子间的关系。结果表明:(1)随着枸杞林生长年限增加,枸杞林地面节肢动物优势类群和稀有类群变化较小,而常见类群变化较大,其优势度和类群数分别在3、10年生枸杞林出现最大值;捕食性、植食性、杂食性和腐食性地面节肢动物个体数均呈现先增后减的趋势,最大值分别出现在8、3、3和8年生枸杞林。(2)随着枸杞林生长年限增加,地面节肢动物个体数和类群数均呈现先增后减的趋势,最大值分别出现在8和3年生枸杞林;Shannon-Wiener和Simpson指数在5和10年生枸杞林地显著降低。(3)RDA和偏RDA分析结果显示,植物高度、植物冠幅和土壤pH是影响枸杞林地面节肢动物群落分布的主要环境因素。研究表明,宁夏干旱绿洲区玉米田转化为枸杞林及在其生长过程中,地面节肢动物群落组成尤其是常见类群发生较大变化,以常见类群组成变化较大为主要特征。玉米田在转为枸杞林的过程中地面节肢动物个体数和类群数均降低,但3~8年生枸杞林具有较高的节肢动物多样性。

An investigation on the community distribution of ground-active arthropods was carried on in Lycium barbarum plantations by the method of pitfall traps.The aged L.barbarum plantations of 1,3,5,8,10 years were selected as sampling sites at Zhongning County in arid oasis region of Ningxia,and the adjacent farmland served as the control.The results show that:(1)There were effect of aged plantations on the dominant index and group numbers of dominant groups and taxa groups,while there was considerable effect on the dominant index and group numbers of common groups.There were peaks of dominance index and group numbers of common group in 3-and 10-year-old plantations.In addition,there was an increasing-decreasing individual trend of predatory,phytophagous,omnivorous and saprophytic arthropods,and there was a peak in 8-,3-,3-and 8-year-old plantations,respectively.(2)There was a increasing-decreasing trend of individual and richness of ground-active arthropods along with aged plantations,with a peak in 8-and 3-year-old plantations,respectively.There was significantly lower Shannon-Wiener index and Simpson index of ground-active arthropods in 5-and 10-year-old plantations,respectively.(3)The results from RDA and pRDA analysis show that plant height,plant crown width and soil pH were the main environmental factors affecting the distribution of ground-active arthropod communities in aged L.barbarum plantations.It is concluded that there was a remarkable change of composition of ground-active arthropod communities during the growth process of L.barbarum plantations converted from the cropland in arid oasis region of Ningxia;especially the composition of common groups showed strong changes.In addition,the individual and richness of ground-active arthropods decreased from the croplands toward aged L.barbarum plantations,whereas there was a high diversity of ground-active arthropods during the period between 3-and 8-year-old L.barbarum plantations.