Liu Ji-Liang, Li Feng-Rui, Niu Rui-Xue, Liu Chang-An, Liu Qi-Jun
Ecology and Agriculture Laboratory, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
Ying Yong Sheng Tai Xue Bao. 2012 Jun;23(6):1551-61.
An investigation was conducted on the status of soil salinization and the structure of soil animal community across six land use/cover types in an arid oasis of middle Heihe River basin, and the methods of redundancy analysis, regression analysis, and path analysis were adopted to analyze the responses of the soil animal community under different land use/cover types and different management modes to the various status of soil salinization. The six land use/cover types were 21-year old shrub land without irrigation and fertilization, 28-year old poplar and 33-year-old pine plantations with irrigation, 27- and 100-year-old farmlands with irrigation and fertilization, and natural grassland, from which all the other five land use/cover types were converted. The results demonstrated that land cover change in the absence of management practices did not lead to a significant change in the abundance and group richness of the soil animal community, while land cover change in the presence of management practices resulted in a significant change in the soil animal community. The evolvement of the soil animal community structure was co-affected by soil pH, soluble salt content, and Na+, Cl, HCO3-, and Mg2+ concentrations, among which, soil soluble salt and Na had the greatest contribution, being the key affecting factors. The abundance and group richness of the soil animal community had significant negative exponential correlations with soil soluble salt content and Na+ concentration, and significant quadratic correlations with soil Mg2+ and HCO3- concentrations. The calculated ecological threshold values of soil Mg2+ and HCO3- concentrations for the abundance and group richness of the soil animal community were 38.7-39.4 mg x kg(-1) and 324.9-335.3 mg x kg(-1), at which, the abundance and group richness reached their peaks 40-43 individuals x m(-2) and 13-14 families x m(-2), respectively. When the Mg2+ and HCO3- concentrations increased further, the abundance and group richness decreased.
对黑河中游干旱绿洲六种土地利用/覆盖类型的土壤盐渍化状况和土壤动物群落结构进行了调查，并采用冗余分析、回归分析和通径分析方法，分析了不同土地利用/覆盖类型和不同管理模式下土壤动物群落对土壤盐渍化各种状况的响应。六种土地利用/覆盖类型分别为：未灌溉施肥的21年生灌木地、有灌溉的28年生杨树人工林和33年生松树人工林、有灌溉施肥的27年生和100年生农田以及天然草地，其他五种土地利用/覆盖类型均由天然草地转变而来。结果表明，在没有管理措施的情况下土地覆盖变化不会导致土壤动物群落的丰度和类群丰富度发生显著变化，而在有管理措施的情况下土地覆盖变化会导致土壤动物群落发生显著变化。土壤动物群落结构的演变受到土壤pH值、可溶性盐含量以及Na+、Cl-、HCO3-和Mg2+浓度的共同影响，其中土壤可溶性盐和Na+的贡献最大，是关键影响因素。土壤动物群落的丰度和类群丰富度与土壤可溶性盐含量和Na+浓度呈显著负指数相关，与土壤Mg2+和HCO3-浓度呈显著二次相关。计算得出土壤动物群落丰度和类群丰富度的土壤Mg2+和HCO3-浓度的生态阈值分别为38.7 - 39.4 mg·kg-1和324.9 - 335.3 mg·kg-1，此时丰度和类群丰富度分别达到峰值40 - 43 个个体·m-2和13 - 14 个科·m-2。当Mg2+和HCO3-浓度进一步增加时，丰度和类群丰富度下降。
