放牧强度对高寒草甸土壤有机碳及其组分的影响

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中图分类号：S812.2 文献标识码：A 文章编号：1007-0435（2026）01-0172-10

Abstract：To evaluate the potential impacts of grazing on grassland soil carbon pools，this study investigated the effects of different grazing intensities on the contents of soil organic carbon（SOC）and its fractions—including particulate organic carbon（POC），mineral-associated organic carbon，light fraction organic carbon （LFOC）， heavy fraction organic carbon（HFOC），easily oxidizable organic carbon（EOC），and dissolved organic carbon （DOC）-in alpine meadows. The results showed that with increasing grazing intensities，the contents of SOC and most of its fractions significantly decreased（except for EOC and DOC），and the stability of the organic carbon pool declined. Under extreme grazing， SOC and POC contents were significantly reduced by 33.54% and 56.21% ，respectively，compared with light grazing. The ratios of EOC/SOC and DOC/SOC exhibited significant fluctuations in response to grazing intensity，making them important indicators for evaluating the impacts of grazing on soil carbon pools in alpine meadows.The contents of SOC and its fractions were significantly correlated with soil total nitrogen（TN）content，bulk density（BD），and aboveground biomass（AGB）， with TN being the key factor influencing SOC and its fractions.Appropriate grazing intensity is crucial for maintaining and enhancing soil quality and carbon pool functions in alpine meadows，as overgrazing reduces SOC accumulation and stability. This study provides ascientific basis for grazing management and soil organic carbon pool conservation in alpine meadows of the East Qilian Mountains.

Key words：Grazing intensity;Alpine meadow;Soil organic carbon;Organic carbon fraction;Physical-chemical fractionation

草地是陆地生态系统的重要组成部分，其碳库储量占陆地生态系统碳库储量的 1/3 ，是大气 CO2 的重要碳汇，在全球碳循环中具有重要作用[1]。（剩余17141字）