不同放牧强度下荒漠草原短花针茅丛枝菌根真菌侵染特征及其影响因素

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中图分类号：S812 文献标识码：A 文章编号：1007-0435（2026）02-0469-09

Abstract：Arbuscular Mycorrhizal Fungi （AMF） play an important role in maintaining the function of grassland ecosystems.Grazing isoneof the mainutilization modes of grasslands，which has a profound effect on the symbiotic relationship between plants and AMF.However，the regulatory efects of grazing on the Stipa breuiflora

AMF symbiosis and its driving mechanisms remain unknown. This study，conducted in the S breviflora grassland of Inner Mongolia，examined the effects of diferent grazing intensities-no grazing，light grazing（LG）， moderate grazing（MG），and heavy grazing（HG）一on the AMF colonization rate in S ，breviflora roots. The results revealed a significant decline in the AMF colonization rate with increasing grazing intensity. The colonization rates were 65.89% ，59. 89% ， 52.89% and 41.33% under different grazing intensities， respectively. Spore density and hyphal length density decreased with increasing grazing intensity. In addition，increased grazing intensity led to longer total root length and smaller root diameter in S .breviflora，along with higher soil density and pH but lower soil organic carbon and available phosphorus. However，soil moisture and nitrate nitrogen content peaked under light grazing.Soil nitrate nitrogenand available phosphorus were identified as the primary factors influencing the reduction in AMF colonization.In conclusion，grazing negatively afects AMF colonization in desert steppes by decreasing nitrogen and phosphorus nutrient effectiveness in the soil. This study pro vides empirical data and theoretical insights that support the development of sustainable grazing management strategies to maintain the health and resilience of desert steppe ecosystems.

Key Words：Desert steppe;Grazing;Stipa breuiflora;Mycorrhizal infection rate

丛枝菌根真菌（Arbuscularmycorrhizal fungi，AMF）是土壤中最常见的根系共生微生物之一，广泛分布于全球各类生态系统[1。（剩余15817字）