Scholarlink

Background and Aims <p>The conversion of forest to farmland leads to substantial reductions in soil organic carbon (SOC), consisting primarily of plant debris carbon (PDC) and microbial necromass carbon (MNC), the latter comprising fungal necromass carbon (FNC) and bacterial necromass carbon (BNC). However, the differential responses of these SOC fractions to land-use change remain poorly understood. This study quantified changes in SOC fractions following forest-to-farmland conversion and explored the underlying drivers in a subtropical context.</p> Methods <p>We employed a space-for-time substitution approach by sampling 27 sites (12 forests, 15 farmlands) in subtropical China. SOC and its fractions—PDC, MNC, FNC, and BNC—were measured, along with soil fertility indicators and microbial community traits.</p> Results <p>SOC, PDC, MNC, FNC, and BNC decreased by 51.4%, 55.3%, 46.0%, 48.1%, and 38.0%, respectively, in agricultural soils compared to forest soils. The relative contributions of PDC, FNC, and BNC to total SOC loss were 62.7%, 30.7%, and 6.6%, respectively, indicating that PDC was the dominant source of carbon loss, while FNC accounted for most of the decline in MNC. These reductions were strongly associated with changes in soil fertility and microbial composition, including declines in SOC, total nitrogen, and nutrient stoichiometry (C/N, C/P, N/P ratios), as well as increases in pH and available phosphorus, accompanied by shifts in microbial abundance and community structure.</p> Conclusions <p>Our findings reveal distinct vulnerabilities among SOC fractions in response to land-use change. These results provide mechanistic insights into SOC depletion pathways and inform strategies for sustainable carbon management in subtropical agricultural systems.</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

Decline and redistribution of soil organic carbon fractions after conversion from subtropical Forest to farmland

  • 期刊论文

  • 发表日期：

    2025年9月23日

查看全文
  • Ruijie Qiu,
  • Qianqian Ma,
  • Jiewen Yang,
  • Ruqin Fan,
  • Shengsen Lin,
  • Xiutong Li,
  • Zhilong Liang,
  • Xiaobo Li

摘要

Background and Aims

The conversion of forest to farmland leads to substantial reductions in soil organic carbon (SOC), consisting primarily of plant debris carbon (PDC) and microbial necromass carbon (MNC), the latter comprising fungal necromass carbon (FNC) and bacterial necromass carbon (BNC). However, the differential responses of these SOC fractions to land-use change remain poorly understood. This study quantified changes in SOC fractions following forest-to-farmland conversion and explored the underlying drivers in a subtropical context.

Methods

We employed a space-for-time substitution approach by sampling 27 sites (12 forests, 15 farmlands) in subtropical China. SOC and its fractions—PDC, MNC, FNC, and BNC—were measured, along with soil fertility indicators and microbial community traits.

Results

SOC, PDC, MNC, FNC, and BNC decreased by 51.4%, 55.3%, 46.0%, 48.1%, and 38.0%, respectively, in agricultural soils compared to forest soils. The relative contributions of PDC, FNC, and BNC to total SOC loss were 62.7%, 30.7%, and 6.6%, respectively, indicating that PDC was the dominant source of carbon loss, while FNC accounted for most of the decline in MNC. These reductions were strongly associated with changes in soil fertility and microbial composition, including declines in SOC, total nitrogen, and nutrient stoichiometry (C/N, C/P, N/P ratios), as well as increases in pH and available phosphorus, accompanied by shifts in microbial abundance and community structure.

Conclusions

Our findings reveal distinct vulnerabilities among SOC fractions in response to land-use change. These results provide mechanistic insights into SOC depletion pathways and inform strategies for sustainable carbon management in subtropical agricultural systems.