西藏年楚河流域沙棘林大型土壤动物群落特征及其影响因素

Characteristics and Influencing Factors of Soil Macrofauna Community of Seabuckthorn Forests in the Nianchu River Basin,Tibet

【目的】为了解西藏年楚河流域沙棘林大型土壤动物群落特征及其与环境因子的关系。【方法】于2020年5月、8月和10月,根据沙棘林的地理分布特征共设置5个样地25个采样点,采用手捡法对75个土壤样品的表面和样品内大型土壤动物进行了调查,同时测得相应的环境因子。【结果】经3次采样,共捕获大型土壤动物798头,隶属于3门5纲17目28科39类群。其中优势类群为蚁科(Formicidae)、狼蛛科(Lycosidae)和石蜈蚣科(Lithobiidae),占总捕获量的62.90%;常见类群10类,占28.32%;稀有类群共26类,占8.77%。单因素方差分析显示,大型土壤动物个体数、类群数、Shannon-wiener多样性指数(H)、Simpson优势度指数(C)和Pielou均匀度指数(E)3个季节间均无显著差异(P>0.05)。Jaccard相似性结果显示,5个样地的土壤动物分布具有一定差异,主坐标分析(PCOA)结果显示,土壤动物在季节间相似程度具有差异性。Pearson相关性分析结果显示,海拔、土壤含水量、土壤温度、pH、总氮和有效磷与土壤动物的群落特征具有显著相关性(P>0.05)。冗余分析(RDA)结果显示,排序轴1和2最能反映大型土壤动物群落类群组成变化的影响因子梯度,有效磷(AP)是显著解释变量。【结论】大型土壤动物各项生物指标3个季节间无显著差异(P>0.05),其群落特征时空分布具有一定差异性,海拔、土壤含水量、土壤温度、pH、总氮和有效磷是影响沙棘林大型土壤动物的重要因子。

【Objective】The current study aims to understand the characteristics of soil macrofauna community and its relationship with environmental factors in seabuckthorn forests of the Nianchu River Basin.【Method】25 sampling and 5 plots sites were set up according to the geographical distribution of seabuckthorn forest in May,August and October of 2020.The soil macrofauna were investigated on the surface of 75 soil samples and in the soil samples by hand picking method,and the corresponding environmental factors were measured at the same time.【Result】After three sampling,a total of 798 soil macrofauna were captured,which belonging to 39 groups,28 families,17 orders,5 classes,3 phyla.The dominant groups were Formicidae,Lycosidae and Lithobiidae,accounting for 62.67%of the total catch.There were 10 common groups,accounting for 28.32%,and 26 rare groups,accounting for 8.77%.The results of One-way ANOVA showed that there were no significant differences in the number individuals and groups of soil macrofauna,Shannon-Wiener diversity index(H),Simpson dominance index(C)and Pielou evenness index(E)among the three seasons(P>0.05).Jaccard similarity results showed that the distribution of soil macrofauna in the five plots had some differences and principal coordinate analysis(PCOA)showed that the similarity degree of soil fauna was different among seasons.The results of Pearson correlation analysis showed that altitude,soil water content,soil temperature,pH,total nitrogen and available phosphorus were significantly correlated with the community characteristics of soil macrofauna(P>0.05).Redundancy analysis(RDA)showed that axis 1 and axis 2 were the most likely to reflect the gradient of influencing factors on the composition of soil macrofauna communities,and available phosphorus(AP)was the significant explanatory variable.【Conclusion】This study showed that there were no significant differences in the biological indexes of soil macrofauna among the three seasons(P>0.05),and the spatial and temporal distribution of community characteristics were different.Altitude,soil water content,soil temperature,pH,total nitrogen and available phosphorus were the important factors affecting soil macrofauna in the seabuckthorn forest.