三江源区人工草地建植对土壤-微生物化学计量特征的影响

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中图分类号：S812.2 文献标识码：A 文章编号：1007-0435（2026）01-0098-09

Abstract：Soil-microbial biomass stoichiometric characteristics serve as a robust indicator of ecosystem nutrient cycling efficiency，yetthe mechanisms bywhich diferent artificial grassland restoration modes influence these traits remain unclear.This study investigated 3-year-old artificial grassands dominated by tall-grass species （SF），short-grass species （XF），and a mixed planting of tall- and short-grass species （SFXF） in the Three

River-Source Region，with severely degraded alpine grassland（CK）as the control. Soil organic carbon （SOC），total nitrogen（TN），total phosphorus（TP），microbial biomass carbon（MBC），nitrogen（MBN）， and phosphorus（MBP） in the 0-10cm layer were measured to analyze their stoichiometric ratios and microbial quotients.The impacts of differentrestoration modes on soil-microbial stoichiometric balance were further elucidated.The results demonstrated that allthree artificial grassland establishment modes significantly enhanced SOC，MBN，and MBP contents.Specifically，，the SF treatment increased soil TN，whereas the XF treatment reduced TN and decreased TP by 50.42% .MBN incresed by 24.36% and 35.59% under SF and XF treatments，respectively. The SFXF treatment decreased the microbial C-quotient by 78.40% ，while the XF treatment elevated the microbial N-quotient by 49.61% ，and the SFXF treatment reduced it by 11. 33% . After res toration，the stoichiometric imbalances in soil-microbial biomass（Cimb：Nimb，Cimb：Pimb，and Nimb：Pimb） increased across alltreatments，with the most pronounced escalation observed in the SFXF treatment.Redundancy analysis （RDA） revealed that soil N：Pand C：P ratios were key drivers of microbial quotient variations. In conclusion，the SFXF mixed planting exerted the most substantial influence on soil-microbial C-N-P cycling.For practical management，supplemental nitrogen fertilization is recommended to optimize plant growth and improve soil quality.

Key words：Artificial grassand;Microbial biomass；Stoichiometric ratio;Microbial quotient; Stoichiometric imbalance

土壤微生物是驱动养分循环与转化过程的关键生物群落，其生物量（Soilmicrobialbiomass，SMB）可作为评估土壤养分库容量和供应潜力的重要生物学指标[1-2]。（剩余17830字）