Plant carbon inputs through shoot, root, and mycorrhizal pathways affect soil organic carbon turnover differently
Plant carbon inputs through shoot, root, and mycorrhizal pathways affect soil organic carbon turnover differently
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植物通过芽、根和菌根途径输入的碳对土壤有机碳周转有不同的影响
DOI：
10.1016/j.soilbio.2021.108322
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发表时间：
2021-06-04
影响因子：
9.7
通讯作者：
Liu, Lingli
中科院分区：
文献类型：
--
作者：
Huang, Junsheng;Liu, Weixing;Liu, Lingli
植物通过地上部、根系和菌根真菌的碳输入是土壤有机碳储量和周转的重要驱动因素。通过这些途径进入土壤的植物碳的数量和比例都受到土壤肥力的影响。然而，我们所知甚少，不同途径的植物碳输入贡献SOC循环在不同的土壤肥力。通过在C3土壤中种植C4牧草糙隐子草，研究了不同肥力条件下，茎、根和丛枝菌根真菌（AMF）对温带草原土壤有机碳周转的影响。我们的四年田间试验表明，土壤肥力较高的螯合更多的地上部，根和AMF来源的C，这主要是由更大的土壤微生物生物量驱动。无论土壤肥力如何，根系对新有机碳形成的贡献最大（44%），而地上部（28%）和AMF（28%）发挥类似但较低的贡献。我们发现，正引发效应诱导的根和AMF更肥沃的土壤，这主要是与更多的根和AMF衍生的C，分别。在所有肥力水平上，根系途径通过启动效应对新的SOC积累和天然SOC损失具有同等的影响，因此没有引起SOC的净变化。但是，AMF途径诱导的引发效应比根途径高60%。AMF引起的启动效应相对于新的SOC积累不成比例地大，导致SOC净损失，特别是在土壤肥力较高的土壤中。总体而言，我们表明，植物C输入通过拍摄，根，和菌根途径有不同的影响SOC营业额。我们的定量估计应该是有价值的，更准确地模拟多少植物来源的C可以被封存在土壤中，并促进我们对未来SOC动态的全球变化的理解。
Plant carbon (C) inputs via shoot, roots, and the associated mycorrhizal fungi are vital drivers of soil organic C (SOC) stock and turnover. Both the amounts and proportions of plant C inputs to the soil through these pathways can be affected by soil fertility. Yet, we know little about how divergent pathways of plant C inputs contribute to SOC cycling under different soil fertility. By growing the C4 grass Cleistogenes squarrosa in C3 soils, we quantified the contributions of shoot, roots, and arbuscular mycorrhizal fungi (AMF) to SOC turnover with different fertility in a temperate grassland. Our four-year field experiment showed that soils with higher fertility sequestered more shoot-, root- and AMF-derived C, which were mainly driven by greater soil microbial biomass. Irrespective of soil fertility, roots contributed the most (44%) to new SOC formation, while shoot (28%) and AMF (28%) exerted similar but lower contributions. We found that the positive priming effects induced by roots and AMF were greater in more fertile soils, which were primarily associated with more root- and AMF-derived C, respectively. Across all the soil fertility levels, root pathway had an equal impact on new SOC accumulation and native SOC losses via priming effects, and thus caused no net SOC changes. However, the priming effect induced by AMF pathway was 60% higher than the root pathway across treatments. The disproportionately large priming effects relative to new SOC accumulation induced by AMF led to net SOC losses, especially in soils with higher fertility. Overall, we demonstrated that plant C inputs through shoot, root, and mycorrhizal pathways have differential impacts on SOC turnover. Our quantitative estimation should be valuable for more accurately modeling how much plant-derived C can be sequestered in the soils and advancing our understanding of future SOC dynamics under global changes.