高寒草甸不同放牧强度下植物地上-地下生物量权衡的变化

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中图分类号：S812 文献标识码：A 文章编号：1007-0435（2025）08-2575-10

Abstract：In recent decades，the exacerbation of overgrazing has posed substantial threats to the stability of alpine meadow ecosystems.Understanding the trade-offs between aboveground and belowground biomass allo cation under diferent grazing intensities，as wellas identifying the driving factors behind these patterns，is criti cal for ecological conservation and restoration initiatives in alpine meadows.This study centered on alpine meadow ecosystems in Hongyuan County on the Tibetan Plateau，which were subjected to four distinct grazing intensity treatments：ungrazed，lightly grazed，moderately grazed，and heavily grazed.Through meticulous measurement of plant aboveground and belowground biomass，and analysis of soil physicochemical properties， we investigated the changes and driving factors behind biomass alocation under different grazing intensities. The results demonstrated that under ungrazed treatment，biomass alocation was skewed towards the belowground.However，as the grazing intensity increased，there was a progresive shift towards aboveground bio mass，resulting ina decrease in the trade-off index.Plant height，plant species richness，soil total carbon，and soil total nitrogen content showed significant positive correlations with the biomass trade-off，whereas soil carbon-nitrogen ratio（C：N） and soil bulk density were significantlyand negatively correlated with the biomass trade-off. Variance partitioning analysis revealed that under light grazing conditions，plant characteristics were the primarydrivers of biomass alocation trade-offs.Nevertheless，as the grazing intensity increased to moder ate and heavy levels，soil factors became more influential. Consequently，management practices aimed at the restoration of degraded alpine meadows should be tailored specifically according to grazing intensity. This involves adjusting vegetation management strategies and implementing targeted measures to restore soil nutrients and effectively promote ecosystem restoration.

Key words：Alpine meadow;Grazing intensity;Biomass trade-off; Plant traits;Soil nutrients

植物生物量作为表征草原生态系统生产力的核心评价指标[1-3]，其空间分配模式深刻反映了植物的资源利用策略。（剩余21061字）