青藏高原高寒草地土壤微生物量碳氮含量特征及其控制要素  

Soil microbial biomass carbon and nitrogen levels and their controlling factors in alpine grassland,Qinghai-Tibet Plateau

作　　者：李洋 王毅[2,3] 韩国栋 孙建 汪亚峰 LI Yang;WANG Yi;HAN Guo-dong;SUN Jian;WANG Ya-feng(College of Grassland,Resource and Environment,Inner Mongolia Agricultural University,Hohhot 010011,China;State Key Laboratory of Tibetan Plateau Earth System Science(LATPES),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;School of Life Sciences,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]内蒙古农业大学草原与资源环境学院,内蒙古呼和浩特010011 [2]中国科学院青藏高原研究所青藏高原地球系统科学国家重点实验室,北京100101 [3]中山大学生命科学学院,广东广州510275

出　　处：《草业学报》2022年第6期50-60,共11页Acta Prataculturae Sinica

基　　金：第二次青藏高原综合科学考察研究项目“气候变化与人类活动对生态系统固碳服务的影响”(No.2019QZKK0307)资助。

摘　　要：青藏高原是我国重要的生态安全屏障,探究地下微生物驱动土壤生化过程,生物量碳氮含量特征及其控制要素,对高寒生态系统功能维持具有重要意义。本研究通过对青藏高原高寒草甸和高寒草原两种草地类型样带调查和研究,探讨了不同高寒草地生态系统类型土壤微生物量碳(MBC)和土壤微生物量氮(MBN)含量特征及其与气候、植物群落和土壤理化性质的关系。结果表明,高寒草甸比高寒草原具有更高的土壤MBC和MBN含量;生长季降水量(GSP)与两种草地类型的MBC和MBN含量呈显著正相关(P<0.01);而生长季均温(GST)仅与高寒草原MBN含量呈显著负相关(P<0.01)。结构方程模型显示,在生长季降水量的影响下,土壤全氮是影响高寒草甸土壤MBC和MBN的主导因子,土壤有机碳是影响高寒草原MBC和MBN的主导因子。研究结果可为高寒草地生态系统可持续管理提供理论参考。The Qinghai-Tibet Plateau is an important geographically isolated and distinctive ecological zone in China.Soil microbes are important drivers of the biogeochemical cycle.Microorganisms are considered the core content of soil biochemical processes.Hence,exploring the content characteristics of soil microbial biomass carbon and nitrogen and their drivers is highly relevant to the understanding of ecosystem function.In this study,a field investigation is conducted in alpine meadows and steppes across the Qinghai-Tibet Plateau.Soil microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN)levels were measured and their relationships with climate,plant community,and soil physicochemical properties were identified.It was found that MBC and MBN contents were higher in alpine meadows than those in alpine steppes.Furthermore,the growing season precipitation(GSP)showed significantly positive correlations with MBC and MBN in both alpine grassland types(P<0.01),while there were significant negative correlations between the growing season temperature(GST)and MBN in the alpine steppe(P<0.01).A structural equation model suggested that soil total nitrogen could mediate the MBC and MBN in the alpine meadow,and soil organic carbon may be the key factor of regulating MBC and MBN in the alpine steppe under the influence of growing season precipitation.The findings provide a theoretical framework for the sustainable management of these grassland ecosystems.

关 键 词：土壤微生物量碳 土壤微生物量氮 高寒草甸 高寒草原 青藏高原 

分 类 号：S812.2[农业科学—草业科学]