准噶尔盆地西南缘山地-绿洲-荒漠生态系统土壤螨类区系时空动态及其作用机制研究

Studies on the faunistic taxonomy,biodiversity and tempo-spatial variation of soil mites is a central topic for discussion in the study of the soil zoology.The soil mites as an important functional components of the soil animals with high species richness,wide distribution,and abundance in microarthropods in soil.They play a vital role such as decomposition of soil organic matters, changing of physico-chemical properties of the soil, cycling of nutrients and energy,ecotoxicological diagnosis of the soil,and monitoring soil environment variations in the ecosystem. In order to provide scientific evidence of the present status ,characteristics of the faunal distribution ,species diversity and tempo-spatial variation of the soil mites of which in relation to the environmental factors in the Mountain-Oasis-Desert ecosystem in the southwest of Junggar basin in Xinjiang, northwest of China,the studies on the faunal distribution,the seasonal dynamics,the interrelationships between the faunal distribution and seasonal dynamics and as well as the soil environmental factors will be conducted by the combined methods of the morphological taxonomy and ecological methods ,using the main parameters such as the elements of fauna,individual number and density,Shannon-Wiener species diversity index, Margalef abundance index ,Pielou evenness index ,Jaccard similarity index ,Sorensen similarity inedx,density-group index.The Euclidean distance(ED) and hierarchical cluster (multidimensional scaling,MDS) analysis,Oribatid mites MGP analysis,maturity index (MI) of the predatory mites,as well as the assemblages of soil mites will be analysed with respect to the site and soil environmental variables in the different habitats using principal component analysis(PCA), canonical correspondence analysis(CCA), multivariate similarity cluster analysis(MSCA)and redundancy analysis(RDA).The seasonal dynamics between the soil mites' faunal ditribution patterns and the main environmental stressors(factors) by the animal community distribution coefficient(ADC) and multivariate similarity cluster(NMDS) in the different habitats and as well as in the different seasons in the ecosystems. In the end ,the comprehensive analysis will be made on the spatio-temporal variability of the soil mites' faunal distribution patterns in that area, and thier response to the environmental factors.The project has an important theoretical significance and scientific value in the comprehensive understanding of the whole China's soil mites fauna,biodiversity,systematic evolution,and the ecological effects of the soil mites ,as well as the bioindicators to the soil quality in our country.

土壤螨类区系及其生态分布规律的研究是土壤动物学研究的中心议题。土壤螨类作为土壤动物中的重要功能组分，分布广、个体数和种群数量最多的小型节肢动物，在陆地生态系统物质循环、能量流动、土壤生态毒理诊断和环境变化监测等方面具有特殊的功能。本项目采用形态特征分类和生态学相结合的方法，研究新疆干旱区山地-绿洲-荒漠生态系统土壤螨类区系分布、时空动态及其与环境要素之间的相关性,重点查明该区域土壤螨类物种现状、区系分布特征、时空动态及其与环境要素之间的相互关系。通过螨类区系的时空分布特征及其与环境要素的相互关系来揭示该区域土壤螨类区系分布特点及其动态变化规律以及环境要素对其影响的作用机制。本研究对全面认识我国土壤螨类区系、物种多样性、系统演变规律以及土壤螨类的生态效应及其环境指示作用等方面都具有重要的理论意义和科学价值。

土壤螨类区系分类及生物多样性研究是土壤动物学研究中的中心议题。土壤螨类是土壤动物中重要功能组分，种类多、分布最广、敏感性强，个体密度和种群数量最多的优势类群，在生态系统物质循环、能量流动、土壤生态毒理诊断和土壤环境变化监测等方面具有特殊的功能。本项目采用了形态特征分类及生态学相结合的方法，重点查明了研究区域土壤螨类现有物种现状、区系分布及群落结构特征、物种多样性及其与环境因素之间的关系。结果显示：①玛纳斯河流域中小型土壤动物资源较为丰富，4门8纲33目，其中甲螨目和弹尾目为优势类群。十二种不同垂直带生境中小型土壤动物个体和多样性在不同季节之间存在显著差异（P<0.05），其中个体数依次为Ⅱ＞Ⅹ＞Ⅰ＞Ⅲ＞Ⅳ＞Ⅴ＞Ⅷ＞Ⅶ＞Ⅸ＞Ⅵ＞Ⅺ＞Ⅶ。多样性指数依次为Ⅲ＞Ⅶ＞Ⅺ＞Ⅸ＞Ⅹ＞Ⅴ＞Ⅷ＞Ⅵ＞Ⅰ＞Ⅳ＞Ⅻ＞Ⅱ。②土壤螨类有4(亚)目114科215属395种的代表，其中甲螨65科112属221种，中气门19科41属77种，前气门24科51属77种，无气门6科11属21种。③区系结构特殊，古北界与东洋界的共有种最多58.24%，并古北界与东洋界的联系最紧密。④个体数和类群数在不同垂直带生境和不同季节之间差异显著（P<0.05），个体数依次为Ⅵ＞Ⅺ＞Ⅷ＞Ⅸ＞Ⅰ＞Ⅹ＞Ⅶ＞Ⅳ＞Ⅴ＞Ⅱ＞Ⅲ＞Ⅻ，季节变化为9月＞4月＞7月＞11月。⑤土壤螨类多样性和丰富度均较高（3.389和，7.854），不同生境之间土壤螨类群落多样性指标均有显著差异（P<0.05），多样性指数(H)依次为Ⅱ＞Ⅴ＞Ⅳ＞Ⅵ＞Ⅲ＞Ⅹ＞Ⅰ＞Ⅸ＞Ⅷ＞Ⅶ＞Ⅺ＞Ⅻ。⑥不同生境土壤螨类群落间的相似性处于中等不相似（0.25~0.50），并聚类和排序结果分为五大环境类型。⑦研究区域不同生境、不同季节以及不同土层之间土壤要素差异显著（P<0.05），影响土壤螨类区系结构和多样性的主要因素是有机质和湿度。⑧不同甲螨种类对不同重金属具有不同的生物富集作用。⑨结果表明，土壤螨类区系及其多样性指标具有明显的生境和季节性特征，湿度、植被类型和人为干扰是影响多样性其动态变化的主要因素。