Quantifying the effects of grazing on soil organic carbon (SOC) decomposition is of crucial importance for understanding soil C dynamics. However, less attention has been paid to the pool‐specific SOC decomposition and the underlying factors associated with each C pool, representing critical knowledge gaps on soil C dynamics. In this study, we applied a state‐of‐the‐art Bayesian data assimilation technique to re‐analyze previous soil incubation data to examine how herbivores influenced the fraction and cumulative respiration of labile and recalcitrant soil C pools from seven edaphically diverse sites in Yellowstone National Park, whereas those variables were not explored in the earlier study. Our results showed that grazing significantly increased cumulative respiration from both labile and recalcitrant C pools. Greater cumulative respiration from the labile C pool was related to grazers increasing labile C pool fractions, while higher cumulative respiration from the recalcitrant C pool was associated with grazers accelerating the decomposition rate of the recalcitrant C pool. Cumulative respiration from both labile and recalcitrant C pools was positively correlated with shoot biomass, soil gravimetric moisture, and soil C and nitrogen content. Our results underscore how knowledge of pool‐specific SOC decomposition can provide a better mechanistic understanding of soil C dynamics along topo‐edaphic gradients in grazed grassland.

中文翻译：

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草食动物刺激黄石国家公园草地中不稳定和顽固的土壤碳库的呼吸

量化放牧对土壤有机碳（SOC）分解的影响对于理解土壤碳动力学至关重要。但是，对特定池的SOC分解以及与每个C池相关的潜在因素的关注较少，这代表了土壤C动力学的关键知识缺口。在这项研究中，我们应用了最新的贝叶斯数据同化技术来重新分析以前的土壤培养数据，以研究草食动物如何影响来自黄石公园七个不同地点的不稳定和顽固的土壤碳库的比例和累积呼吸国家公园，而先前的研究未探讨这些变量。我们的结果表明，放牧显着增加了不稳定和顽固的碳库的累积呼吸。不稳定的C池中较大的累积呼吸与放牧者增加了不稳定的C池分数有关，而顽固的​​C池中较高的累积呼吸与放牧者加速顽固的C池的分解速率有关。不稳定和顽固的碳库的累积呼吸与枝条生物量，土壤重量水分以及土壤碳和氮含量呈正相关。我们的结果强调了特定于池的SOC分解的知识如何能够更好地从机械角度理解放牧草地上沿地形-坡度的土壤碳动态。而顽固性C库中较高的累积呼吸与放牧者加速了顽固性C库的分解速率有关。不稳定和顽固的碳库的累积呼吸与枝条生物量，土壤重量水分以及土壤碳和氮含量呈正相关。我们的结果强调了特定于池的SOC分解的知识如何能够更好地从机械角度理解放牧草地上沿地形-坡度的土壤碳动态。而顽固性C库中较高的累积呼吸与放牧者加速了顽固性C库的分解速率有关。不稳定和顽固的碳库的累积呼吸与枝条生物量，土壤重量水分以及土壤碳和氮含量呈正相关。我们的结果强调了特定于池的SOC分解的知识如何能够更好地从机械角度理解放牧草地上沿地形-坡度的土壤碳动态。