State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Ecol Lett. 2021 May;24(5):1018-1028. doi: 10.1111/ele.13723. Epub 2021 Mar 11.
Elucidating the processes underlying the persistence of soil organic matter (SOM) is a prerequisite for projecting soil carbon feedback to climate change. However, the potential role of plant carbon input in regulating the multi-layer SOM preservation over broad geographic scales remains unclear. Based on large-scale soil radiocarbon (∆ C) measurements on the Tibetan Plateau, we found that plant carbon input was the major contributor to topsoil carbon destabilisation despite the significant associations of topsoil ∆ C with climatic and mineral variables as well as SOM chemical composition. By contrast, mineral protection by iron-aluminium oxides and cations became more important in preserving SOM in deep soils. These regional observations were confirmed by a global synthesis derived from the International Soil Radiocarbon Database (ISRaD). Our findings illustrate different effects of plant carbon input on SOM persistence across soil layers, providing new insights for models to better predict multi-layer soil carbon dynamics under changing environments.
阐明土壤有机物质（SOM）持久存在的过程是预测土壤碳对气候变化反馈的前提。然而，植物碳输入在调节广泛地理范围内多层 SOM 保存方面的潜在作用仍不清楚。基于对青藏高原的大规模土壤放射性碳（∆C）测量，我们发现尽管表层土壤 ∆C 与气候和矿物变量以及 SOM 化学组成有显著关联，但植物碳输入是导致表层土壤碳不稳定的主要因素。相比之下，铁铝氧化物和阳离子对矿物的保护在深层土壤中对 SOM 的保存变得更为重要。这些区域观测结果得到了国际土壤放射性碳数据库（ISRaD）的全球综合分析的证实。我们的研究结果说明了植物碳输入对不同土壤层 SOM 持久性的影响，为模型提供了新的见解，以更好地预测在变化环境下的多层土壤碳动态。
