戈壁生态系统蚁穴微生境对大型土壤动物多样性的影响

Effects of ant nest microhabitats on the diversity of soil macrofauna in gobi ecosystems

收获蚁蚁穴是戈壁生态系统中重要的微生境,它通过汇集凋落物和改善土壤环境强烈影响动植物的分布及多样性。鉴于此,本文选择戈壁荒漠收获蚁(Messor desertus)蚁穴为研究对象,于2020年5月、6月和10月利用陷阱法调查了蚁穴及毗邻裸地大型土壤动物的种类组成及数量变化,并分析其影响要素。结果表明:(1)10月,蚁穴和裸地间大型土壤动物群落组成存在显著差异,而5月和6月二者间相差较小,10月(62.9%)蚁穴和裸地大型土壤动物的平均相异性高于5月(34.8%)和6月(39.3%);(2)5月,蚁穴大型土壤动物均匀度指数显著低于裸地,6月,蚁穴大型土壤动物活动密度和类群丰富度均显著高于裸地,10月,蚁穴大型土壤动物类群丰富度和多样性指数均显著高于裸地;(3)荒漠收获蚁蚁穴显著提高了其他食性土壤动物的活动密度及类群丰富度,还增强了捕食性和非捕食性土壤动物的相互作用关系并改变了荒漠收获蚁与蚁穴大型土壤动物类群的种间相互作用关系;(4)pRDA排序结果表明,土壤电导率、全氮和粉粒含量是影响蚁穴和裸地大型土壤动物分布的主要土壤因子。总之,戈壁生态系统荒漠收获蚁蚁穴微生境提高了大型土壤动物多样性,改变了大型土壤动物类群间的营养和非营养关系,这会影响大型土壤动物的营养结构及其功能。

Aims:Harvest ant nests are an important microhabitat in gobi ecosystems that greatly affect the distribution and diversity of animals and plants by enhancing litter and improving the soil environment.This study analyzed the distribution pattern and influencing factors of soil macrofauna diversity between ant nest and adjacent bare ground microhabitats.Methods:We investigated the assemblage of soil macrofauna in gobi Messor desertus ant nests and adjacent bare ground microhabitats using pitfall traps in May,June,and October 2020.Results:(1)The community composition of soil macrofauna differed between ant nest and adjacent bare ground microhabitats and showed obvious seasonal variations.Soil macrofauna communities of ant nests and adjacent bare ground differed significantly in October,with an average dissimilarity of 62.9%.Slight differences were also observed in May and June,with 34.8%and 39.3%average dissimilarity,respectively.(2)The activity density and groups richness of soil macrofauna were significantly higher in ant nests than in adjacent bare ground microhabitats in June;the groups richness and diversity index of soil macrofauna communities were also higher in ant nests in October,and the evenness index of soil macrofauna communities was significantly lower in ant nests than bare ground microhabitats in May.(3)Ant nests significantly increased the activity density and groups richness,which increased the interactions between predatory and non-predatory soil macrofauna and altered the interactions between Messor desertus and some soil macrofauna groups.(4)pRDA showed that soil electrical conductivity,total nitrogen,and silt content were the main soil factors driving the distribution of soil macrofauna communities between ant nest and adjacent bare ground microhabitats.Conclusion:Messor desertus ant nests increased the diversity of soil macrofauna communities and altered the trophic and non-trophic relationship among soil macrofauna groups,which affects the trophic structure and ecological function of soil macrofauna communities.