Wang Yang, Slotsbo Stine, Damgaard Christian Frølund, Holmstrup Martin
Section for Terrestrial Ecology, Department of Ecoscience, Aarhus University, Building 1120, C.F. Møllers Allé 4, 8000 Aarhus C, Denmark.
Environ Sci Technol. 2023 Feb 28;57(8):3085-3094. doi: 10.1021/acs.est.2c07497. Epub 2023 Feb 15.
Climate change has resulted in an increased occurrence of summer droughts in large parts of the world. Low soil moisture has marked impacts on the physiology of soil invertebrates and lowers degradation rates of organic contaminants in soil. Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic contaminants that readily accumulate in the lipids of soil organisms. Here, we exposed springtails (Collembola, small soil living arthropods) to phenanthrene (a common PAH) in combination with a range of soil water contents to investigate the combined effects of these factors on the bioaccumulation, survival, recruitment, and body growth in a full factorial experiment. The results showed that phenanthrene up to 60 mg/kg dry soil had moderate effects on survival (<20%), whereas dry soil (4% soil water content) caused approximately 60% mortality. The bioaccumulation of phenanthrene increased almost 3-fold when soil water content decreased from 22 to 4%. We observed a joint effect of low soil water content and phenanthrene on recruitment, suggesting a synergistic interaction. The recruitment EC50 values of phenanthrene decreased from approximately 40 mg/kg dry soil at 22% soil water content to approximately 10 mg/kg dry soil at 12% soil water content. Our results show that the effects of phenanthrene are more pronounced in dry soil partly because bioaccumulation is enhanced when soils become dry.
气候变化导致世界大部分地区夏季干旱的发生频率增加。土壤湿度低对土壤无脊椎动物的生理有显著影响，并降低了土壤中有机污染物的降解速率。多环芳烃（PAHs）是疏水性污染物，容易在土壤生物的脂质中积累。在此，我们将跳虫（弹尾目，小型土壤节肢动物）暴露于菲（一种常见的多环芳烃）与一系列土壤含水量组合的环境中，通过全因子实验研究这些因素对生物累积、存活、繁殖和身体生长的综合影响。结果表明，高达60毫克/千克干土的菲对存活率有中等影响（<20%），而干燥土壤（土壤含水量4%）导致约60%的死亡率。当土壤含水量从22%降至4%时，菲的生物累积增加了近3倍。我们观察到低土壤含水量和菲对繁殖有联合效应，表明存在协同相互作用。菲的繁殖半数效应浓度（EC50）值从土壤含水量22%时的约40毫克/千克干土降至土壤含水量12%时的约10毫克/千克干土。我们的结果表明，菲在干燥土壤中的影响更为显著，部分原因是土壤变干时生物累积会增强。
