银北盐碱地土壤动物多样性与土壤因子的相关性

Soil Fauna Diversity and Its Relations with Soil Factors in Saline-alkali Soil in Northern Yinchuan of Ningxia

为探讨不同利用方式的改良盐碱地土壤动物多样性与土壤因子的相关性,于2010-06-08调查银北改良盐碱地的玉米田、枸杞田、油葵田和未改良盐碱地的土壤动物,并测定土壤水分含量、pH、土壤碱化度和全盐量。采用干漏斗法分离土壤0～20cm的土壤动物。共获得土壤动物7纲12目28类。分析表明,土壤动物的优势类群为弹尾目(56.58%),蜱螨类(18.04%),蜘蛛类(8.03%)和膜翅目蚁科(6.01%)。土壤动物多样性因土地不同利用方式以及受干扰程度而表现出差异。改良的玉米地具有最高的多样性H′和丰富度D。群落相似性分析显示,改良玉米地和改良枸杞地有较高的相似性。典范对应分析(CCA)表明,土壤动物与土壤因子的相关性高达100%,说明盐碱地土壤因子变化影响土壤动物的分布,土壤全盐量和土壤含水量对土壤动物群落的分布影响最大,不同类群对环境因子响应存在差异。

In order to investigate the relationship between soil fauna diversity and soil factors in different types of improved saline land,we investigated the soil fauna communities at original saline-alkali soil and 3 types of improved saline land,corn field,wolfberry field and sunflower field in northern Yinchuan of Ningxia from June to August 2010.Some soil factors including soil water content,soil pH value,total salt content（TS） and exchange sodium percentage（ESP） were determined.The Modified Tullgren method was used to separate cropland soil animals from soil samples（0-20 cm）.A total of 2029 individuals were collected,belonging to 7 classes,12 orders and 28 groups.The results showed that Collembola,Acarina,Arane and Formicidae of Hymenoptera were dominant groups,accounting for 56.58%,18.04%,8.03% and 6.01%.The structure and diversity of soil fauna community were varied under different land practices and disturbances in this saline-alkali soil system.The highest Shannon-Wiener index and richness index were in the improved corn field.Community similarity showed that there were higher Jaccard coefficients between the improved corn field and the improved wolfberry field,implying that the group composition of soil animal community was similar to a certain extent in the two saline-alkali soil ecosystems.CCA explained 100% of the correlation between groups and four soil variables,suggesting that the occurrence of many groups was related to changes in ecological conditions.Among the four factors,soil water content and total salt content were the most effective variables on the species occurrence.The CCA ordination showed the response of soil fauna to soil factors was obvious difference in saline-alkali soil.