Yin Kejie, Gong Lu, Ma Xinyu, Li Xiaochen, Sun Xiaonan
College of Ecology and Environment, Xinjiang University, Urumqi 830017, China.
Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830017, China.
Microorganisms. 2025 Jul 24;13(8):1729. doi: 10.3390/microorganisms13081729.
The priming effect (PE), a microbially mediated process, critically regulates the balance between carbon sequestration and mineralization. This study used soils from different soil depths (0-20 cm, 20-40 cm, and 40-60 cm) under forest in the Tianshan Mountains as the research object. An indoor incubation experiment was conducted by adding three concentrations (1% SOC, 2% SOC, and 3% SOC) of C-labelled glucose. We applied C isotope probe-phospholipid fatty acid (PLFA-SIP) technology to investigate the influence of readily labile organic carbon inputs on soil priming effect (PE), microbial community shifts at various depths, and the mechanisms underlying soil PE. The results indicated that the addition of C-labeled glucose accelerated the mineralization of soil organic carbon (SOC); CO emissions were highest in the 0-20 cm soil layer and decreased trend with increasing soil depth, with significant differences observed across different soil layers ( < 0.05). Soil depth had a positive direct effect on the cumulative priming effect (CPE); however, it showed negative indirect effects through physico-chemical properties and microbial biomass. The CPE of the 0-20 cm soil layer was significantly positively correlated with C-Gram-positive bacteria, C-Gram-negative bacteria, and C-actinomycetes. The CPE of the 20-40 cm and 40-60 cm soil layers exhibited a significant positive correlation with cumulative mineralization (CM) and microbial biomass carbon (MBC). Glucose addition had the largest and most significant positive effect on the CPE. Glucose addition positively affected PLFAs and particularly microbial biomass. This study provides valuable insights into the dynamics of soil carbon pools at varying depths following glucose application, advancing the understanding of forest soil carbon sequestration.
激发效应（PE）是一个由微生物介导的过程，对碳固存和矿化之间的平衡起着关键的调节作用。本研究以天山山脉森林下不同土壤深度（0 - 20厘米、20 - 40厘米和40 - 60厘米）的土壤为研究对象。通过添加三种浓度（1% SOC、2% SOC和3% SOC）的碳标记葡萄糖进行室内培养实验。我们应用碳同位素探针 - 磷脂脂肪酸（PLFA - SIP）技术来研究易分解有机碳输入对土壤激发效应（PE）、不同深度微生物群落变化以及土壤PE潜在机制的影响。结果表明，添加碳标记葡萄糖加速了土壤有机碳（SOC）的矿化；CO排放以0 - 20厘米土层最高，并随土壤深度增加呈下降趋势，不同土层间差异显著（< 0.05）。土壤深度对累积激发效应（CPE）有正向直接影响；然而，它通过物理化学性质和微生物生物量表现出负向间接影响。0 - 20厘米土层的CPE与碳 - 革兰氏阳性菌、碳 - 革兰氏阴性菌和碳 - 放线菌显著正相关。20 - 40厘米和40 - 60厘米土层的CPE与累积矿化（CM）和微生物生物量碳（MBC）呈显著正相关。添加葡萄糖对CPE的正向影响最大且最显著。添加葡萄糖对PLFAs有正向影响，尤其对微生物生物量有影响。本研究为施用葡萄糖后不同深度土壤碳库的动态变化提供了有价值的见解，增进了对森林土壤碳固存的理解。
