我国典型土壤中铜对白符跳(Folsomia candida)的毒性阈值及其预测模型

为确定我国土壤中Cu对白符跳的毒性阈值并建立其预测模型，以外源添加的方式研究了我国9种典型土壤（江西红壤、安徽黄棕壤、重庆紫色土、云南黄红壤、湖南水稻土、山东潮土、黑龙江黑土、新疆灰漠土、陕西垆土）中Cu对模式生物——白符跳（Folsomia candida）存活率与繁殖率的影响.结果表明:白符跳存活率对Cu毒害的敏感性远低于繁殖率.9种土壤中基于w（TCu）实测值推导的土壤Cu对白符跳繁殖率的EC₅₀（半数效应浓度）变化范围为65~668 mg/kg，表明不同土壤中Cu的毒性阈值差异显著，但基于w（Cu_Ca）（Cu_Ca为CaCl₂溶液提取的Cu）推导的不同土壤中EC₅₀的差异有所减小.相关性分析表明，基于w（TCu）实测值推导的EC₅₀值与土壤pH、w（CaCO₃）均呈显著正相关，相关系数分别为0.801和0.670.进一步利用回归分析建立了基于pH和w（OM）的土壤Cu对白符跳繁殖的EC₅₀预测模型——lg（EC₅₀）=0.213+0.288pH+0.016 w（OM），基于该模型预测与推导的EC₅₀值之间相关性较好.研究显示，氯化钙提取态Cu的存在能在一定程度上解释不同土壤中Cu对白符跳繁殖的EC₅₀值的差异，pH和w（OM）可较好地预测不同土壤中Cu对白符跳繁殖的EC₅₀值. 

Toxicity Thresholds and Prediction Model of Copper to Soil-Dwelling Springtail (Folsomia candida) in Chinese Soils

To determine the toxicity thresholds of Cu to springtails in Chinese soils and establish prediction model of Cu toxicity, the effects of exogenous Cu on the survival and reproduction of model organism-Folsomia Candida were studied in nine typical types of soils (red soil in Jiangxi, yellow-brown soil in Anhui, purple soil in Chongqing, yellowish-red soil in Yunnan, paddy soil in Hunan, fluvoaquic soil in Shandong, black soil in Heilongjiang, gray desert soil in Xinjiang and loessal soil in Shaanxi). The results showed that sensitivity of the survival to Cu toxicity was much lower than that of reproduction. The EC₅₀(concentration causing 50% toxic effect) of soil Cu for the reproduction based on measured total Cu concentrations ranged from 65 mg/kg to 668 mg/kg, indicating that very significant differences of Cu toxicity thresholds in different soils. However, when calculated based on CaCl₂ extracted Cu, the EC₅₀ values between different soils were much smaller. The correlation analysis showed that both soil pH and calcium carbonate content were significantly and positively correlated with the EC₅₀ value based on the measured total Cu, and the correlation coefficients were 0.801 and 0.670, respectively. The further developed prediction model of Cu toxicity thresholds for reproduction based pH and organic matter using regression analysis was that lg(EC₅₀)=0.213 + 0.288pH + 0.016w(OM), and the predicted EC₅₀ well correlated with calculated EC₅₀. This study showed that to some extent the existence of CaCl₂ extracted Cu could explain the differences of EC₅₀ for the reproduction between soils, and soil pH and organic matter could well predict the EC₅₀ of Cu for the reproduction between soils.