Fu Haoran, Chen Hong, Ma Zhengbo, Liang Guopeng, Chadwick David R, Jones Davey L, Wanek Wolfgang, Wu Lianghuan, Ma Qingxu
Ministry of Education Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China.
State Key Laboratory of Soil Pollution Control and Safety, Zhejiang University, Hangzhou, China.
Glob Chang Biol. 2025 Aug;31(8):e70413. doi: 10.1111/gcb.70413.
Soil organic carbon (C) is derived primarily from plant and microbial necromass; however, the global distribution and contribution of different necromass inputs to soil C storage remain unclear. We conducted a global meta-analysis encompassing 2410 observations from 249 microbial necromass studies and 786 observations from 72 plant residue studies. The results showed that the content of microbial-derived C (10.63 ± 0.39 g C kg soil) exceeded that of plant-derived C (lignin phenol carbon (LPC), 5.63 ± 0.45 g C kg soil), across the 0-100 cm soil profile, with fungal necromass carbon (FNC; 7.24 ± 0.21 g C kg) contributing the most to soil C-a pattern consistently observed across all depths. In addition, in the topsoil (0-20 cm), forests (9.39 ± 1.22 g C kg) and grasslands (9.73 ± 1.74 g C kg) showed significantly higher LPC contents than croplands and wetlands; therefore, cropland expansion significantly reduces microbial- and plant-derived carbon stocks in topsoil. Global FNC, BNC, and LPC stocks were estimated to be 211 Pg (95% CI: 156-270 Pg), 71 Pg (95% CI: 59-88 Pg) and 168 Pg (95% CI: 151-186 Pg) in topsoil, respectively. Lower soil pH and mean annual temperature were associated with higher FNC, BNC, and LPC contents, particularly in high-latitude regions like North America. These results demonstrate that microbial necromass, rather than plant residues, dominates soil C storage globally. These findings highlight the need for management strategies that address both land-use change and rising temperatures to protect microbial and plant C pools.
土壤有机碳（C）主要来源于植物和微生物残体；然而，不同残体输入对土壤碳储存的全球分布和贡献仍不明确。我们进行了一项全球荟萃分析，涵盖了来自249项微生物残体研究的2410个观测数据和来自72项植物残体研究的786个观测数据。结果表明，在0至100厘米的土壤剖面中，微生物源碳含量（10.63±0.39克碳/千克土壤）超过了植物源碳含量（木质素酚碳（LPC），5.63±0.45克碳/千克土壤），其中真菌残体碳（FNC；7.24±0.21克碳/千克）对土壤碳的贡献最大——这一模式在所有深度均一致观察到。此外，在表层土壤（0至20厘米）中，森林（9.39±1.22克碳/千克）和草原（9.73±1.74克碳/千克）的LPC含量显著高于农田和湿地；因此，农田扩张显著降低了表层土壤中微生物源和植物源碳储量。全球表层土壤中FNC、BNC和LPC储量估计分别为211Pg（95%置信区间：156 - 270Pg）、71Pg（95%置信区间：59 - 88Pg）和168Pg（95%置信区间：151 - 186Pg）。较低的土壤pH值和年均温度与较高的FNC、BNC和LPC含量相关，特别是在北美等高纬度地区。这些结果表明，全球范围内土壤碳储存主要由微生物残体而非植物残体主导。这些发现凸显了制定应对土地利用变化和气温上升的管理策略以保护微生物和植物碳库的必要性。
