Arbuscular mycorrhizal (AM) fungi are key players in the soil carbon (C) and nitrogen (N) cycles; on the one hand, AM fungi have been influenced by global changes, while on the other hand, they are involved in shaping the future climate. However, few field studies have combined AM fungi with both elevated temperatures and N deposition to examine their potential combined effects on the stocks of soil C and N in temperate meadow ecosystems. A 5-year experiment was conducted to explore the effects of AM fungal reductions on soil C and N stocks under elevated temperatures and N deposition. The stock of soil C and N and the C:N ratio were measured. The results showed that AM fungi significantly reduced soil C stocks by 8.5% across all treatment combinations compared to the AM fungi suppression treatment, and slight soil C accumulation was detected across the five years. The response of the soil C stocks was not influenced by elevated temperatures and N deposition simultaneously. The soil N stocks in the treatments without AM fungal suppression were, on average, 9.7% lower across all treatments than those in the AM fungal suppression treatment. AM fungi, elevated temperatures, and N deposition did not affect the soil C:N ratio. The robust decreases in soil C and N stocks caused by AM fungi observed here, even when combined with other global changes, suggest that AM fungi might accelerate soil C losses in temperate meadow ecosystems; however, there is a strong potential for reduced soil N accumulations to mitigate the negative impact of increasing N deposition on the stability of grassland ecosystems under future global changes. Overall, our results highlight that the effect of AM fungi on soil C and N stocks has a high resistance to global warming and N deposition in temperate meadow ecosystems.

丛枝菌根 (AM) 真菌是土壤碳 (C) 和氮 (N) 循环中的关键参与者；一方面，AM真菌受到全球变化的影响，另一方面，它们参与了未来气候的塑造。然而，很少有实地研究将 AM 真菌与升高的温度和 N 沉积结合起来，以检查它们对温带草甸生态系统中土壤 C 和 N 储量的潜在联合影响。进行了一项为期 5 年的实验，以探讨在升高的温度和 N 沉积下，AM 真菌减少对土壤 C 和 N 库的影响。测量了土壤 C 和 N 的存量以及 C:N 比。结果表明，与 AM 真菌抑制处理相比，AM 真菌在所有处理组合中显着减少了 8.5% 的土壤碳储量，5 年间检测到轻微的土壤碳积累。土壤碳库的响应不受温度升高和氮沉积同时影响。在所有处理中，没有 AM 真菌抑制的处理中的土壤 N 库平均比 AM 真菌抑制处理中的土壤 N 库低 9.7%。AM 真菌、升高的温度和 N 沉积不影响土壤 C:N 比。此处观察到的 AM 真菌引起的土壤 C 和 N 库的大幅减少，即使与其他全球变化相结合，表明 AM 真菌可能会加速温带草甸生态系统中土壤 C 的流失；然而，在未来的全球变化下，减少土壤氮积累以减轻氮沉积增加对草地生态系统稳定性的负面影响有很大的潜力。总体，