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以内陆干旱区黑河中游绿洲边缘区天然沙质草地及其转变的人工梭梭灌木林(21a)、人工杨树林(28a)、人工樟子松林(33a)和农田(开垦27a和100a)为研究对象,对6种样地土壤盐渍化和大型土壤动物群落特征进行调查,采用多变量排序、多元回归和通径分析及一元回归分析等方法,研究了不同土地覆被和管理措施下土壤动物群落组成及对土壤盐碱环境变化的响应.结果表明:在缺乏管理措施的情况下,单纯改变土地覆被并不会显著影响土壤动物群落结构;而在有管理措施的情况下,土地覆被变化与管理措施耦合可显著改变土壤动物群落结构.土壤动物群落演变受到土壤pH、可溶性盐及Na+、Cl-、HCO3-、Mg2+浓度的共同影响,其中Na+和可溶性盐含量的贡献率最大,是关键影响因子.土壤动物密度和类群丰富度与土壤中的Na+和可溶性盐含量呈显著负指数函数关系,与Mg2+和HCO3-含量呈显著二次曲线关系.研究区土壤动物密度和类群丰富度在Mg2+和HCO3-含量达到生态阈值点(分别为38.7～39.4mg·kg-1和324.9～335.3mg·kg-1)时达到峰值(40～43只·m-2和13～14科·m-2).此后,随着Mg2+和HCO3-含量的增加,土壤动物密度和类群丰富度下降.
Natural sandy grassland in the marginal zone of the oasis in the middle reaches of the Heihe River in inland arid region and its changing characteristics of artificial Haloxylon ammodendron forest (21a), artificial poplar forest (28a), artificial Pinus sylvestris var. Mongolica (33a) and farmland (reclamation 27a and 100a) , The soil salinization and the characteristics of soil macrofauna communities in six sampling plots were investigated. By using multivariate sorting, multivariate regression, path analysis and one-dimensional regression analysis, the soil fauna community under different land cover and management measures Composition and response to changes in soil salinity and alkalinity.The results show that in the absence of management measures, simply changing the land cover does not significantly affect the soil fauna community structure; however, under the management measures, the land cover change Coupling with management measures can significantly change the structure of soil animal community.The evolution of soil animal community is affected by soil pH, soluble salts and Na +, Cl-, HCO3- and Mg2 + concentrations, and the contribution of Na + and soluble salt content is the most important Impact factors.The density and abundance of soil fauna showed a negative exponential function with the content of Na + and soluble salt in the soil, but significantly correlated with the contents of Mg2 + and HCO3- Quadratic curve.The soil animal density and taxonomic abundance peaked at the ecological threshold (38.7-39.4 mg · kg-1 and 324.9-335.3 mg · kg-1, respectively) when the content of Mg2 + and HCO3- reached 40 ~ 43 · m-2 and 13 ~ 14 families · m-2) .After that, with the increase of Mg2 + and HCO3-, the density and abundance of soil animals decreased.