高原鼢鼠干扰强度对祁连山东段高寒草甸大型土壤动物功能群特征及空间分布的影响

Abstract

为明晰高原鼢鼠干扰对大型土壤动物类群分布和功能群特征影响，选取祁连山东段高原鼢鼠典型分布高寒草甸，依据鼠丘密度将研究区划分4个干扰梯度，调查各干扰区植物、群落结构、土壤理化性质和大型土壤动物功能群组成。采用冗余分析方法探讨植物土壤因子对土壤动物功能群组成和分布的影响。结果表明：研究区植食性土壤动物为优势功能群，极重度干扰区植食性功能群丰富度和Shannon多样性指数显著高于中度和重度干扰区（P<0.05）；高原鼢鼠干扰对高寒草甸土壤动物群落稳定和相似性影响较小；冗余分析表明土壤温度、紧实度、全氮和全钾以及莎草科生物量和植物物种均匀度均显著影响高寒草甸土壤动物功能群的空间分布（P<0.05），其中土壤温度对土壤动物功能群分布影响最为显著。;To understand the effects of trophic interaction and environmental heterogeneity on spatial distribution and functional group characteristics of soil macro-fauna in alpine meadow, we selected four zokor mound density gradients and investigated plant community structure, soil physicochemical properties and functional communities of soil fauna (herbivore, predator, detritivore and omnivore group) to explore the dominant environmental factors which influence the spatial distribution of soil fauna community. Our results showed that the herbivore functional group was the dominant soil fauna group in alpine meadow and the characteristic index of herbivore group was more sensitive to plateau zokor disturbances. The richness and Shannon index of the herbivore group in the extremely severe disturbance intensity were significantly higher than that in the moderate and severe disturbance intensity (P<0.05). The plateau zokor disturbances had a little effect on the stability and similarity of soil fauna. Furthermore, the redundancy analysis indicated that the spatial distribution of soil fauna functional groups was significantly affected by soil temperature, compaction, total nitrogen, total potassium, sedge biomass and plant species evenness(P<0.05), and soil temperature was the dominant factor to influence soil fauna functional groups.