Rhizosphere processes play a critical role in soil organic carbon (SOC) cycling that is primarily regulated by temperature. Understanding the response of rhizospheric SOC decomposition to global warming, which is called temperature sensitivity (Q₁₀), is pivotal for predicting the feedback of SOC cycling to global warming. However, the rhizosphere effects (REs) on Q₁₀ and their underlying mechanisms in forest ecosystems remain unclear. Here, the REs on Q₁₀ for Cunninghamia lanceolata and three understory ferns (e.g., Woodwardia japonica, Parathelypteris glanduligera and Microlepia marginata) in a subtropical forest were explored using a novel incubation procedure with periodically changing temperatures based on the mean annual temperature. Our results showed that the positive REs on Q₁₀ were observed for all plant species, which ranged from 33% to 88%, and P. glanduligera exhibited higher REs on Q₁₀ than C. lanceolata. The positive REs on Q₁₀ were associated with the rhizospheric nitrogen (N) availability and microbial properties. The REs on N component (i.e., the REs on total N, NH₄⁺ and NO₃⁻ along the first PCA axis), which is the most important driver, had a positive direct effect on the REs on Q₁₀. Furthermore, the rhizospheric microbial biomass and the REs on microbial residues were also positively related to the REs on Q₁₀. Overall, these findings highlight that plant-covered soils have high risks of C emissions under planetary warming, underscore the importance of root-soil interactions for accurately predicting SOC dynamics and reveal that rhizospheric nutrients and microbial properties drive the feedback of the root-associated SOC cycle to global warming.

根际过程在主要受温度调节的土壤有机碳 (SOC) 循环中起着关键作用。了解根际 SOC 分解对全球变暖的响应，称为温度敏感性 ( Q ₁₀ )，对于预测 SOC 循环对全球变暖的反馈至关重要。然而，对Q ₁₀的根际效应 (REs)及其在森林生态系统中的潜在机制仍不清楚。在这里，对RE的Q ₁₀为杉木和三个林下蕨类植物（例如，狗脊，金星蕨和鳞盖边翠) 在亚热带森林中使用一种新的孵化程序进行了探索，该程序根据年平均温度定期改变温度。我们的结果表明，在所有植物物种中都观察到Q ₁₀上的阳性 RE ，范围从 33% 到 88%，并且P. deaduligera在Q ₁₀上表现出比C. lanceolata更高的 RE 。Q ₁₀上的正 RE与根际氮 (N) 可用性和微生物特性相关。N 分量上的 REs（即总 N、NH ₄ ⁺和 NO ₃ ^-上的 REs沿第一个 PCA 轴），这是最重要的驱动因素，对Q ₁₀上的 RE 产生了积极的直接影响。此外，根际微生物生物量和微生物残留上的 REs 也与Q ₁₀上的 REs 呈正相关。总体而言，这些发现强调了植物覆盖的土壤在全球变暖下具有较高的碳排放风险，强调了根-土壤相互作用对于准确预测 SOC 动态的重要性，并揭示了根际养分和微生物特性驱动根相关 SOC 的反馈循环到全球变暖。