物种敏感性分布在土壤中镍生态阈值建立中的应用研究

Application of Species Sensitivity Distribution in Deriving of Ecological Thresholds for Nickel in Soils

本文利用不同累计概率分布函数拟合了基于中国土壤的17个物种的镍毒理学数据。结果表明,BurrⅢ在X轴(浓度)方向及Y轴的较小累计概率范围内拟合优度较佳。在构建土壤中镍物种敏感性分布曲线时,利用镍生物毒害模型归一化处理能修正土壤性质的影响且可更好地体现物种敏感性差异,相比于未归一化处理的结果更具科学性。在此基础上结合镍的生物毒害模型利用BurrⅢ构建了中国土壤4种典型情景中的物种敏感性分布曲线,同时确定了不同土壤情景下的镍生态阈值,即酸性土壤、中性土壤(包括水稻土)、碱性非石灰性土壤和石灰性土壤的镍生态阈值分别为6.5、47.5、218.8mg.kg-1和120.3mg.kg-(1以土壤中外源镍为单位)。

Althouth species sensitivity distribution has been applied widely in deriving water ecological quality criteria,its application for soils is seldom.In this paper,nickel toxicity threshold of 17 species based on Chinese soils were fitted with different cumulative probability distribution functions.The result showed that BurrⅢ fitted better than other functions in the X axis direction and Y axis with lower cumulative frequency.Utilization of nickel ecotoxicity regression models in the establishment of species sensitivity distribution curves could correct the difference of soil properties and reflect the species sensitivity difference better.It was more robust scientifically to normalize toxicity threshold with ecotoxicity regression models compared with that without normalization.On the basis of nickel ecotoxicity regression models the species sensitivity distribution curves in four representative scenarios of Chinese soils were fitted with BurrⅢ.The nickel soil ecological thresholds were derived from the species sensitivity distribution curves,they were 6.5,47.5,218.8 mg added Ni·kg-1 soil and 120.3 mg added Ni·kg-1 soil for acidic,neutral,alkaline non-calcareous and calcareous soils,respectively.