Key Laboratory of the Ministry of Agriculture for Arable Land Conservation in South China, Key Laboratory of Guangdong Province for Land Use and Consolidation, College of Natural Resources and Environment, South China Agricultural University, 510642, Guangzhou, China; ISTO, UMR 7327, CNRS-Université D'Orléans, 41071, Orléans, France.
Key Laboratory of the Ministry of Agriculture for Arable Land Conservation in South China, Key Laboratory of Guangdong Province for Land Use and Consolidation, College of Natural Resources and Environment, South China Agricultural University, 510642, Guangzhou, China.
Ecotoxicol Environ Saf. 2020 Jun 1;195:110513. doi: 10.1016/j.ecoenv.2020.110513. Epub 2020 Mar 23.
The study aims to investigate effect of earthworm activity on metal bioavailability in soils using their BSAF-metals. Based on a microcosmic laboratory experiment, epigeic species Amynthas corticis (A. corticis) and endogeic species Amynthas robustus (A. robustus) were cultured in two types of soils contaminated by Cd, Zn, Pb and Cu for 120 days. Earthworm characteristics (i.e. numbers, biomass and BSAF), soil properties (i.e. pH, organic C and N contents along with their components such as mineralization and microbial masses) and DTPA extracted metals in soil were determined. After the incubation, the biomass and survival numbers of both earthworm species decreased significantly (P < 0.05). The accumulation of Cd, Zn and Pb in earthworm tissues and BSAF-metals were earthworm species dependent. According to two-way ANOVA, BSAF-Pb clearly showed the effect of different species of earthworms while BSAF-Cu indicated an interactive effect of earthworms and soil type. Earthworms changed soil properties significantly, especially for mineralized C (C), dissolved N (N) and pH (P < 0.05). Earthworm activity increase DTPA extracted Zn and Cu, and the effect of A. robustus were stronger than for A. corticis. Redundancy analysis (RDA) showed that BSAF-Cu and BSAF-Pb contributed for respectively 51.9% and 51.7% of soil properties and DTPA metal changes, indicating that the effects of BSAF-Cu and BSAF-Pb on soil properties and on metal bioavailability in soil were similar. BSAF-Cu, indicating the interactive effect of earthworms and soil, accounted for 38.5% and 45.1% of soil properties and soil metal bioavailability changes. BSAF-Pb, representing the effect of earthworm species, accounted for 13.3% and 6.6% of soil property and soil metal bioavailability variations. Stepwise regression indicated that earthworm might change soil properties through their activities and interactions with soil, and hence increase heavy metal bioavailability. It suggested that BSAF is an important indicator for evaluating the effect of earthworm activity on soil metal bioavailability and designing remediation strategies.
本研究旨在利用蚯蚓的 BSAF-金属来研究蚯蚓活动对土壤中金属生物有效性的影响。基于一项微观实验室实验，在两种受 Cd、Zn、Pb 和 Cu 污染的土壤中培养了表栖物种 Amynthas corticis（A. corticis）和内栖物种 Amynthas robustus（A. robustus）120 天。测定了蚯蚓特征（数量、生物量和 BSAF）、土壤性质（pH、有机 C 和 N 含量及其组成，如矿化和微生物量）以及土壤中 DTPA 提取的金属。孵育后，两种蚯蚓的生物量和存活数均显著下降（P<0.05）。蚯蚓组织中 Cd、Zn 和 Pb 的积累与蚯蚓种类有关。根据双因素方差分析，BSAF-Pb 明显显示了不同蚯蚓种类的影响，而 BSAF-Cu 则显示了蚯蚓和土壤类型的交互作用。蚯蚓显著改变了土壤性质，特别是矿化 C（C）、溶解 N（N）和 pH（P<0.05）。蚯蚓活动增加了 DTPA 提取的 Zn 和 Cu，且 A. robustus 的效果强于 A. corticis。冗余分析（RDA）表明，BSAF-Cu 和 BSAF-Pb 分别对土壤性质和 DTPA 金属变化的贡献率为 51.9%和 51.7%，表明 BSAF-Cu 和 BSAF-Pb 对土壤性质和土壤金属生物有效性的影响相似。BSAF-Cu 表明了蚯蚓和土壤的交互作用，占土壤性质和土壤金属生物有效性变化的 38.5%和 45.1%。BSAF-Pb 代表了蚯蚓种类的作用，占土壤性质和土壤金属生物有效性变化的 13.3%和 6.6%。逐步回归表明，蚯蚓可能通过其活动及其与土壤的相互作用来改变土壤性质，从而增加重金属的生物有效性。这表明 BSAF 是评估蚯蚓活动对土壤金属生物有效性影响和设计修复策略的重要指标。
