Ecological responses and functional significance of paddy crust in the southern Chinese environment

• Published in: Environmental pollution (1987) Vol. 349; p. 123908
• Main Authors: Kuang, Xiaolin, Hu, Yiyi, Chen, Shaoning, Ge, Yili, Hu, Yiling, Song, Huijuan, Song, Ke, Peng, Liang
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.05.2024
• Subjects: Agriculture; Bacteria - drug effects; Bacterial diversity; China; Ecosystem; Environmental factor; Environmental Monitoring - methods; Metals, Heavy - analysis; Oryza; Paddy crusts; Random forest; Soil - chemistry; Soil Microbiology; Soil Pollutants - analysis; Structural equation model; China; Environmental factor; Random forest; Bacterial diversity; Paddy crusts; Structural equation model
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2024.123908

Paddy Crusts (PC) play a pivotal role in the migration and transformation of heavy metals within paddy ecosystems, situated at the critical intersection of air, water, and soil. This study focused on PC samples from heavy metal-contaminated rice paddies in six southern Chinese provinces. It's the first time we've screened and quantified the impact of nutrition, physicochemical properties, and heavy metals on bacterial diversity in PC. Our results highlight the significant influence of zinc, total nitrogen, and soil manganese on bacterial diversity. Using structural equation models, we identified the pathways through which these three types of environmental factors shape bacterial diversity. Heavy metal indicators and physical and chemical indicators exerted a direct negative effect on bacterial diversity in PC, while nutritional indicators had a direct and significant positive effect on bacterial diversity. Variance partitioning analysis revealed heavy metals had the most significant impact, accounting for 7.77% of the total effect. Moreover, the influence of heavy metals on bacterial diversity increased as diversity decreased, ranging from 3.81% to 42.09%. To remediate specific heavy metal pollution, our proposed method involves cultivating indigenous bacteria by controlling these environmental factors, based on an analysis of the interplay among bacterial diversity, environmental variables, and heavy metal bioconcentration factors. These findings enhance our understanding of PC and provide insights into rice field heavy metal pollution mitigation. [Display omitted] •The impact of three types of environmental factors on biodiversity in PC was quantified.•Zn, N in water and Mn in soil can significantly affect PC biodiversity.•Heavy metals and physicochemical indicators have a direct negative effect on diversity.•Heavy metals have a greater impact on PC with low biodiversity.