Scholarlink

<p>Sediments are key components of aquatic ecosystems, mediating water–sediment exchange and regulating biogeochemical processes. However, most existing studies treat riverbed sediments as a homogeneous whole, rarely systematically classifying and comparing them based on permeability. As a result, significant gaps remain in understanding the spatial distribution patterns, physicochemical differentiation, and environmental controlling mechanisms of different sediment types in large river systems. We surveyed bed sediments along the &gt; 5,000&#xa0;km mainstem of the Yangtze River. The permeability of sediments was estimated based on the median grain size (D<sub>50</sub>), and they were classified as permeable or impermeable according to the estimated permeability. For each class, we quantified physicochemical properties, characterized overlying water chemistry, mapped spatial distribution patterns, and assessed the relative influence of sediment physical attributes and water chemistry on sediment chemical composition. Permeable sediments were widespread, occurring at 50% of the sampled sites, and exhibited distinct spatial patterns compared to impermeable sediments. Organic matter in both sediment types was primarily derived from terrestrial sources. Carbon and nitrogen contents were significantly lower in permeable sediments. In permeable sediments, C and N dynamics were mainly regulated by overlying water chemistry, whereas in impermeable sediments they were more strongly influenced by sediment physical properties. Permeable sediments are a widespread and ecologically significant component of the Yangtze River. Incorporating sediment-type classification into large-river studies can improve understanding of spatial heterogeneity and environmental controls on sediment biogeochemistry. Given their widespread occurrence and distinct nutrient-processing dynamics, permeable sediments represent an often-overlooked zone of carbon and nitrogen cycling in large rivers. Recognizing their role will enhance predictions of riverine biogeochemical fluxes, inform sediment management, and support restoration strategies under changing hydrological and land-use regimes.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Spatial patterns and environmental controls of permeable and impermeable sediments in the Yangtze river mainstem

  • 期刊论文

  • 发表日期：

    2026年2月20日

查看全文
  • Xuebi Xie,
  • Zaiting Xiang,
  • Ziqi Wang,
  • Man Liu,
  • Yinke Li,
  • Weibo Wang

摘要

Sediments are key components of aquatic ecosystems, mediating water–sediment exchange and regulating biogeochemical processes. However, most existing studies treat riverbed sediments as a homogeneous whole, rarely systematically classifying and comparing them based on permeability. As a result, significant gaps remain in understanding the spatial distribution patterns, physicochemical differentiation, and environmental controlling mechanisms of different sediment types in large river systems. We surveyed bed sediments along the > 5,000 km mainstem of the Yangtze River. The permeability of sediments was estimated based on the median grain size (D50), and they were classified as permeable or impermeable according to the estimated permeability. For each class, we quantified physicochemical properties, characterized overlying water chemistry, mapped spatial distribution patterns, and assessed the relative influence of sediment physical attributes and water chemistry on sediment chemical composition. Permeable sediments were widespread, occurring at 50% of the sampled sites, and exhibited distinct spatial patterns compared to impermeable sediments. Organic matter in both sediment types was primarily derived from terrestrial sources. Carbon and nitrogen contents were significantly lower in permeable sediments. In permeable sediments, C and N dynamics were mainly regulated by overlying water chemistry, whereas in impermeable sediments they were more strongly influenced by sediment physical properties. Permeable sediments are a widespread and ecologically significant component of the Yangtze River. Incorporating sediment-type classification into large-river studies can improve understanding of spatial heterogeneity and environmental controls on sediment biogeochemistry. Given their widespread occurrence and distinct nutrient-processing dynamics, permeable sediments represent an often-overlooked zone of carbon and nitrogen cycling in large rivers. Recognizing their role will enhance predictions of riverine biogeochemical fluxes, inform sediment management, and support restoration strategies under changing hydrological and land-use regimes.