Scholarlink

<p>Global grasslands can sequester soil organic carbon (SOC) while maintaining ecosystem function, thereby mitigating climate change. SOC consists of components with varying stability and turnover rates, such as particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). While these components have been extensively studied in the surface layer (0–30 cm), their distribution and controls in deeper layers remain poorly understood. This study combined precise measurements of POC and MAOC across seven sequential depth layers down to 2 m at 17 Inner Mongolian grassland sites with a global dataset to elucidate their vertical distribution patterns and underlying controls. Results showed that POC generally dominated MAOC in Inner Mongolian grassland soils, albeit with regional variations in this dominance. Interestingly, the proportion of MAOC to total SOC (MAOC:(MAOC+POC)), indicating SOC stability, increased with depth in the upper 0–50 cm but decreased below 50 cm, suggesting that environmental factors at depth may constrain POC decomposition and MAOC formation. POC accumulation was positively influenced by the mean annual precipitation in the top 30 cm and negatively affected by soil pH down to 50 cm. Contrastingly, MAOC was coregulated by the clay and silt content (CS) and aluminum (Al) oxide in surface soils (0–30 cm), whereas Al oxide dominated from 30 to 100 cm. Notably, MAOC:(MAOC+POC) correlated significantly with CS across all depths, underscoring the persistent role of physical protection mechanisms in deeper layers. These findings highlight depth-specific accumulation patterns and controls of POC and MAOC in the Inner Mongolian grasslands, indicating that optimizing SOC sequestration under changing climate and management scenarios requires depth-specific strategies that target both short-term POC enhancement and long-term MAOC stabilization.</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

Depth-dependent accumulation and controls of particulate and mineral-associated organic carbon in Inner Mongolian grasslands

  • 期刊论文

  • 发表日期：

    2025年8月19日

查看全文
  • Haojun Zheng,
  • Shuai Zhang,
  • Guocheng Wang,
  • Mingming Wang,
  • Yunlong Hu,
  • Yuchen Wei,
  • Kang Xu,
  • Haigang Li,
  • Shixiang Zhao,
  • Biao Zhu,
  • Jinfeng Chang,
  • Zhou Shi,
  • Su Ye,
  • Changqing Song,
  • Wen Zhang,
  • Zhongkui Luo

摘要

Global grasslands can sequester soil organic carbon (SOC) while maintaining ecosystem function, thereby mitigating climate change. SOC consists of components with varying stability and turnover rates, such as particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). While these components have been extensively studied in the surface layer (0–30 cm), their distribution and controls in deeper layers remain poorly understood. This study combined precise measurements of POC and MAOC across seven sequential depth layers down to 2 m at 17 Inner Mongolian grassland sites with a global dataset to elucidate their vertical distribution patterns and underlying controls. Results showed that POC generally dominated MAOC in Inner Mongolian grassland soils, albeit with regional variations in this dominance. Interestingly, the proportion of MAOC to total SOC (MAOC:(MAOC+POC)), indicating SOC stability, increased with depth in the upper 0–50 cm but decreased below 50 cm, suggesting that environmental factors at depth may constrain POC decomposition and MAOC formation. POC accumulation was positively influenced by the mean annual precipitation in the top 30 cm and negatively affected by soil pH down to 50 cm. Contrastingly, MAOC was coregulated by the clay and silt content (CS) and aluminum (Al) oxide in surface soils (0–30 cm), whereas Al oxide dominated from 30 to 100 cm. Notably, MAOC:(MAOC+POC) correlated significantly with CS across all depths, underscoring the persistent role of physical protection mechanisms in deeper layers. These findings highlight depth-specific accumulation patterns and controls of POC and MAOC in the Inner Mongolian grasslands, indicating that optimizing SOC sequestration under changing climate and management scenarios requires depth-specific strategies that target both short-term POC enhancement and long-term MAOC stabilization.