Scholarlink

<p>Understanding soil-specific organic carbon dynamics is crucial for optimizing carbon sequestration strategies in subtropical plantations. However, the variations in soil organic carbon (SOC) and its fractions in a chronosequence of plantation forest soils across different soil types remain poorly understood. In this study, we examined SOC, particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) in topsoil (0–20&#xa0;cm) and subsoil (20–100&#xa0;cm) along a chronosequence of Chinese fir (<i>Cunninghamia lanceolata</i> [Lamb.] Hook) plantations in red and yellow soils of southern subtropical China. Our results revealed a fundamental divergence in carbon stabilization pathways: red soils presented geochemical preservation mediated by precipitation-driven nutrient shifts, while yellow soils showed dominant physical protection. In red soils, SOC, MAOC contents and the MAOC/SOC ratio significantly increased with stand age, driven primarily by geochemical preservation via non-crystalline iron-aluminum oxides (variance explained, VE = 15.8% and 30.2% in the topsoil and subsoil, respectively). Conversely, yellow soils showed a structural-driven pathway, while topsoil SOC and MAOC contents decreased with stand age, whereas subsoil SOC, POC and MAOC contents increased. Additionally, the POC/SOC ratio in both layers exhibited a rising tendency as stand age increased. This preferential accumulation of labile carbon in yellow soils was facilitated by structural improvements, specifically, alleviated compaction (decreased bulk density; VE = 26.6% and 16.2% in the topsoil and subsoil, respectively), enhanced aggregate stability (mean weight diameter; VE = 13.0%), and improved hydrological conditions (soil water content; VE = 38.1%). Our study suggests that forest carbon management must be soil-dependent, focusing on geochemical stabilization in red soils and physical protection in yellow soils to effectively stabilize SOC.</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

Soil-specific changes of soil organic carbon and its fractions in a chronosequence of Chinese fir plantations in southern subtropical China

  • 期刊论文

  • 发表日期：

    2026年6月23日

查看全文
  • Yiqun Chen,
  • Qi Xia,
  • Shumei Wang,
  • Meng Zhang,
  • Shirong Liu

摘要

Understanding soil-specific organic carbon dynamics is crucial for optimizing carbon sequestration strategies in subtropical plantations. However, the variations in soil organic carbon (SOC) and its fractions in a chronosequence of plantation forest soils across different soil types remain poorly understood. In this study, we examined SOC, particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) in topsoil (0–20 cm) and subsoil (20–100 cm) along a chronosequence of Chinese fir (Cunninghamia lanceolata [Lamb.] Hook) plantations in red and yellow soils of southern subtropical China. Our results revealed a fundamental divergence in carbon stabilization pathways: red soils presented geochemical preservation mediated by precipitation-driven nutrient shifts, while yellow soils showed dominant physical protection. In red soils, SOC, MAOC contents and the MAOC/SOC ratio significantly increased with stand age, driven primarily by geochemical preservation via non-crystalline iron-aluminum oxides (variance explained, VE = 15.8% and 30.2% in the topsoil and subsoil, respectively). Conversely, yellow soils showed a structural-driven pathway, while topsoil SOC and MAOC contents decreased with stand age, whereas subsoil SOC, POC and MAOC contents increased. Additionally, the POC/SOC ratio in both layers exhibited a rising tendency as stand age increased. This preferential accumulation of labile carbon in yellow soils was facilitated by structural improvements, specifically, alleviated compaction (decreased bulk density; VE = 26.6% and 16.2% in the topsoil and subsoil, respectively), enhanced aggregate stability (mean weight diameter; VE = 13.0%), and improved hydrological conditions (soil water content; VE = 38.1%). Our study suggests that forest carbon management must be soil-dependent, focusing on geochemical stabilization in red soils and physical protection in yellow soils to effectively stabilize SOC.