Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
Sci Total Environ. 2022 Dec 10;851(Pt 1):158121. doi: 10.1016/j.scitotenv.2022.158121. Epub 2022 Aug 18.
Riparian zone, an important land-water interface, plays an essential role in maintaining the ecological health of rivers, whereas the effects of Polycyclic aromatic hydrocarbons (PAHs) on the health of biological communities in riparian groundwater remain undetermined. To understand the responses of multiple communities to environmental variables, the distribution and ecosystem risk of 16 PAHs have been investigated in the Beiluo River, China. The distribution of multiple communities in riparian groundwater was investigated by environmental DNA metabarcoding, including 16S rRNA, 18S rRNA, and COI gene sequencing for bacteria, microbial eukaryotes (including algae, fungi, and protozoa), and metazoan, respectively, followed by correlation analysis between multiple communities and PAH contamination levels. The concentration of PAHs in the Beiluo River ranged largely from 35.32 to 728.59 ng/L. Here, the Shannon's diversity index of bacteria (Firmicutes) decreased possibly due to the occurrence of Pyrene, which mainly derives from coal and biomass combustion. Furthermore, the reduced richness of fungi (Ascomycota, Basidiomycota) and algae (Chlorophyta, Chrysophyceae) can be attributed to the presence of medium molecular weight (MMW) PAHs (Pyrene, Benz(a)anthracene, Chrysene), and low molecular weight (LMW) PAHs (Naphthalene, Fluorene, Phenanthrene). The richness and Shannon's diversity index of metazoan (Arthropoda) were promoted owing to MMW PAHs (Chrysene, Fluoranthene) generated from coal and biomass combustion and traffic emission. The ecological risk of PAHs in the groundwater environment of the Beiluo River was characterized as low to medium, where LMW and MMW PAHs posed higher risk than the high molecular weight (HMW) compounds. Overall, this study provides insights into the structures of riparian multi-biological communities altered by PAHs.
河流滨岸带是陆地-水域的重要界面，在维持河流生态系统健康方面发挥着重要作用，而多环芳烃（PAHs）对滨岸带地下水生物群落健康的影响仍不确定。为了了解多个生物群落对环境变量的响应，本研究采用环境 DNA 宏条形码技术，对中国北洛河滨岸带地下水中的 16 种 PAHs 的分布及生态风险进行了研究。通过 16S rRNA、18S rRNA 和 COI 基因测序，分别对细菌、微生物真核生物（包括藻类、真菌和原生动物）和后生动物进行了环境 DNA 宏条形码分析，研究了滨岸带地下水中多生物群落的分布，并对多生物群落与 PAH 污染水平之间的相关性进行了分析。北洛河 PAHs 的浓度范围较大，为 35.32-728.59ng/L。其中，细菌（Firmicutes）的 Shannon 多样性指数可能由于源于煤和生物质燃烧的芘的存在而降低。此外，真菌（Ascomycota、Basidiomycota）和藻类（Chlorophyta、Chrysophyceae）丰度的降低可能归因于中分子量（MMW）PAHs（芘、苯并[a]蒽、屈）和低分子量（LMW）PAHs（萘、芴、菲）的存在。由于煤和生物质燃烧以及交通排放产生的 MMW PAHs（苯并[c]芘、荧蒽），后生动物（节肢动物门）的丰富度和 Shannon 多样性指数增加。北洛河滨岸带地下水环境中 PAHs 的生态风险特征为低-中，其中 LMW 和 MMW PAHs 比高分子量（HMW）化合物具有更高的风险。总之，本研究为 PAHs 改变滨岸带多生物群落结构提供了新的认识。
