秦岭土壤环境变化对土壤动物群落的影响

摘要

为探讨秦岭土壤环境变化对土壤动物群落结构的影响,采用取样调查法,调查了秦岭太白山自然保护区不同类型土壤环境中土壤动物群落,共捕获土壤动物5 048只,分别隶属于23个类群.土壤动物群落随土壤环境的改变而发生明显的变化.土壤理化特性测定表明:腐殖质和氮磷钾3种营养元素在5种土壤环境中的含量随着海拔增高向上逐渐增加,特别是在棕壤森林土、暗棕壤森林土和亚高山草甸土中的含量比较高;供试土壤酸度随海拔高度增加逐渐增加:土壤pH值由7.08降至5.18;土壤容重总体上呈先减小后增加的趋势;而土壤孔隙度的变化规律刚好相反;土壤质地逐渐从壤质粘土变为沙质壤土;土壤微生物数量逐渐增加,其中土壤细菌和土壤放线菌数量在暗棕壤森林土中最高,土壤真菌数量在棕壤森林土为最高,而在亚高山草甸土和高山草甸土中,土壤微生物的数量陡然下降.多样性指数研究结果表明,土壤动物群落随土壤环境的改变而发生明显的变化:土壤动物多样性指数依次为棕壤森林土＞褐色森林土＞亚高山草甸土＞暗棕壤森林土＞高山草甸土.Shannon-Wiener多样性指数和Pielou均匀度指数能较好地反映不同土壤环境中土壤动物群落的多样性状况,并且和Berger-Parker生态优势度指数呈明显的负相关.%In order to understand the vertical distribution features of soil-animal community structure in different types of forest soil ecosystems in Qinling Mountains, we used the sampling survey method to investigate soil animal community in different types of forest soil ecosystem in National Nature Reserve of Taibai Mountain. Totally 5 048 of animals were captured, belonging to 23 groups. The soil physical and chemical test data showed that with the increase of altitude, the percentage of the humus and the nutrient elements, total N, total P, total K all increased gradually, especially in brown forest soil, dim brown forest soil, and sub-alpine meadow soil. Soil pH value decreased with the increase of altitude, from 7. 08 to 5. 18. With the increase altitude, the soil unit weight(g ?cm"3)decreased first and then increased, but the variation of soil porosity was just opposite. The soil texture changed gradually from the loamy clay to the sandy loam. The quantity of soil microorganism increased gradually, in which the quantities of soil bacteriarnand soil actinomyces were the most in dim brown forest soil, and the quantitiy of soil fungi was the most in brown forest soil, but the quantity of soil microorganism declined sharply in sub-alpine meadow soil and alpine meadow soil. The results of the diversity of groups and individuals of soil animals by using of the diversity index to analyze showed that there was a significant change of the soil animal communities with different types of forest soil ecosystem; the Shannon-Wiener index (H) of individuals of soil fauna was: brown forest soil>dark brown forest soil>sub-alpine meadow soil>dim brown forest soil>alpine meadow soil. The Shannon-Wiener index(H) of individuals of soil fauna and the Pielou evenness index(J) of individuals of soil fauna both could better reflect the condition of the composition and diversity of soil animal community in different types of forest soil ecosystem, and they had an opposite trend to the Berger-Parker dominant index (D).