沿海土壤中溶解有机物由降雨引起的迁移:地表和地下下水之间的分布
1Key Laboratory of the Three Gorges Reservoir Region's Eco-environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
Environmental research
|December 15, 2025
概括
岸边的下水运输陆地碳. 斜坡和土地利用对溶解有机物 (DOM) 产量产生重大影响,农业用地对非点污染的贡献最大. 表面下水带有更多可生物利用的有机物,并与微生物活动有关.
科学领域:
- 环境科学 环境科学
- 土壤科学 土壤科学
- 水文学 水文学
背景情况:
- 沿海流水是陆地碳转移到水生系统的关键途径.
- 排水中的溶解有机物 (DOM) 量和成分受斜坡梯度和土地使用类型的影响.
- 对于DOM在地表和地下流水中的特定迁移行为,我们仍然不完全理解.
研究的目的:
- 系统地调查在不同坡度和土地使用类型下的人工降雨期间的DOM迁移.
- 量化地表和地表下水流中的溶解有机碳 (DOC), (DON) 和 (DOP) 度.
- 分析DOM的成分和生物可用性,与排水类型和环境因素相关.
主要方法:
- 进行了人工降雨模拟实验.
- 采用了不同的斜坡梯度和土地使用类型 (野生草地,农业用地,裸露土地).
- DOM数量 (DOC,DON,DOP) 和成分 (类似蛋白质的,化程度) 在地表和地下水流样本中进行了分析.
主要成果:
- 平均DOC度因土地用途而异:13.89-48.17毫克/升 (野生草地),16.39-30.11毫克/升 (农业用地) 和5.66-22.51毫克/升 (裸露土地).
- 农业土地的排水量显著高于其他土地用途的DON和DOP度 (2.6-8.2倍),表明其在非点污染中的作用.
- 增加的斜坡梯度增强了生物可用的有机物质的运输,特别是来自农田的有机物质.
- 表面下水的蛋白质类有机物含量较高,与微生物活动相关的湿度较低,而地下下水的湿度较高,表明植物残留来源.
- 表面流失DOM的成分与土壤微生物群落的关系比地下流失DOM更为密切.
结论:
- 土地利用和斜坡梯度是DOM通过河岸流水出口的关键驱动因素.
- 由于DON和DOP的增加,农业用地对非点源污染构成重大风险.
- 表面下水流DOM更不稳定,受到微生物的影响,而地下下水流DOM更受人性化,来自植物残留物.
- 了解这些DOM迁移模式对于管理水质和沿海生态系统中的碳循环至关重要.
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