Abstract: Soil carbon and nitrogen are the primary nutrient sources of plant growth,playing a crucial role in maintaining soil fertility,enhancing soil microbial activity,and mitigating global climate change. This study used the Qinghai Provincial Alpine Grassland-Livestock Management Technology Platform （https：//ghcd.agiot.cn） to investigates the impacts of different grazing patterns on various carbon and nitrogen components. The results showed that grazing yak and Tibetan sheep separately significantly increased microbial biomass carbon,whereas mixed grazing significantly decreased it. In terms of microbial biomass nitrogen,both separate and mixed grazing significantly reduced its content. Grazing had no significant effect on soil total carbon and soil total nitrogen. The influences of grazing on microbial biomass carbon,microbial biomass nitrogen,soluble organic carbon,and soluble organic nitrogen were more pronounced than that on soil total carbon and soil total nitrogen. From the perspective of microbial biomass,mixed grazing was preferable in alpine grasslands,as separate grazing exacerbated soil microbial carbon limitation in these ecosystems. This study quantified the carbon and nitrogen content of different soil components in alpine grasslands under various grazing patterns,providing a scientific basis for sustainable grassland management in this region.

Key words: Grazing, Qinghai-Xizang Plateau, Alpine grassland, Microbial biomass

摘要： 土壤碳、氮是植物生长主要的养分来源,对于维持土壤肥力,提高土壤微生物活性以及对缓解全球气候变化具有重要意义。本研究依托青海省高寒草地-家畜系统适应性管理技术平台（https：//ghcd.agiot.cn）研究不同放牧方式对不同组分碳、氮的影响。结果表明：牦牛、藏羊单独放牧显著增加了微生物生物量碳,混合放牧显著降低了微生物生物量碳；对微生物生物量氮而言,单独放牧和混合放牧均显著降低了微生物生物量氮含量,放牧对土壤总碳和土壤总氮无显著影响。放牧对微生物生物量碳、微生物生物量氮、可溶性有机碳和可溶性有机氮的影响大于对土壤总碳和土壤总氮的影响。从微生物生物量的角度分析,高寒草地以混合放牧为优,单独放牧会加剧高寒草地土壤微生物碳限制。本试验确定了不同放牧方式下高寒草地土壤不同组分碳、氮含量,可以为该区域草地的可持续管理提供科学依据。

关键词: 放牧, 青藏高原, 高寒草地, 微生物生物量