中国北方温带草原土壤微生物残体碳含量及驱动因素

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关键词：中国北方温带草原;微生物残体碳;细菌残体碳；真菌残体碳;驱动因素中图分类号：S812.2 文献标识码：A 文章编号：1007-0435（2026）02-0573-08

Abstract：Microbial necromass carbon （MNC） constitutes a significant component of soil organic carbon （SOC）and plays a vital role in maintaining and enhancing carbon sequestration capacity of grassland ecosystems.The temperate grasslands of northern China represent a crucial component of global grassand ecosystems，but systematic understanding of their microbial necromasscarbon content and its driving factors remains limited.To address this gap，this study established transects along a natural rainfall gradient from east to west in Inner Mongolia，covering three grassland types： meadow grassland，typical grassand，and desert grassland.

Soilamino sugar content was measured using the biomarker method.By integrating climate and soil characteristics，the study systematically analyzed the distribution of soil microbial necromass carbon and its driving factors. Results indicate that the average microbial necromass carbon content in topsoil is 10.65g⋅kg-1 ，comprising 4.79g⋅kg-1 bacterial necromass carbon and 14.80g⋅kg-1 fungal necromass carbon. Structural equation modelingreveals that microbial necromass carbon is primarily regulated by annual mean temperature，dissolved organic carbon，and pH . These findings deepen our understanding of the distribution patterns and driving mechanisms of microbial necromass carbon in northern China's temperate grasslands，providing scientific support for regional grassland carbon management and enhancing soil carbon sequestration potential.

Key words： Temperate grasslands of northern China;Microbial necromass carbon;Bacterial necromass carbon; Fungal necromass carbon;Driving factors

土壤微生物作为陆地生态系统的重要组成，在有机碳的形成、转换与稳定等方面发挥着关键作用。（剩余17734字）