西班牙农业科学研究所Garca-Palacios, Pablo团队的一项最新研究，揭示了寒冷地区表层矿物土壤中颗粒有机碳的优势。该项研究成果发表在2024年1月4日出版的《自然—地球科学》上。

研究人员综合了对矿物层中颗粒和矿物相关有机碳的现场配对观测结果，以及实验变暖数据，来调查颗粒部分是否在寒冷地区占主导地位，以及这是否与变暖导致的土壤有机碳损失高于其他(较温和)生物群落有关。研究发现，在永久冻土区和非永久冻土区以及在北极和高山生态系统中，前30cm矿物土壤中的土壤有机碳以颗粒碳为主或共同占主导地位，而在亚北极环境中则不是这样。

研究结果表明，与较温和的生物群落相比，寒冷地区的土壤有机碳最容易受到变暖的影响，而这种脆弱性是由较高的气候变暖导致的颗粒碳损失介导的。寒冷地区大量的土壤碳积累，似乎主要分布在更脆弱的颗粒部分，而不是更持久的矿物相关部分，这支持了强有力的、积极的陆地碳—气候反馈的可能性。

据了解，土壤有机碳储量最大的地区是北极、亚北极和高山生物群落等寒冷地区，这些地区的变暖速度快于全球平均水平。区分颗粒有机碳和矿物相关有机碳可以限制全球土壤有机碳储量预估变化的不确定性。然而，当各学者评估寒冷地区对陆地碳—气候反馈的贡献时，没有考虑碳组分。

附：英文原文

Title: Dominance of particulate organic carbon in top mineral soils in cold regions

Author: Garca-Palacios, Pablo, Bradford, Mark A., Benavente-Ferraces, Iria, de Celis, Miguel, Delgado-Baquerizo, Manuel, Garca-Gil, Juan Carlos, Gaitn, Juan J., Goi-Urtiaga, Asier, Mueller, Carsten W., Panettieri, Marco, Rey, Ana, Sez-Sandino, Tadeo, Schuur, Edward A. G., Sokol, Noah W., Tedersoo, Leho, Plaza, Csar

Issue&Volume: 2024-01-04

Abstract: The largest stocks of soil organic carbon can be found in cold regions such as Arctic, subarctic and alpine biomes, which are warming faster than the global average. Discriminating between particulate and mineral-associated organic carbon can constrain the uncertainty of projected changes in global soil organic carbon stocks. Yet carbon fractions are not considered when assessing the contribution of cold regions to land carbon–climate feedbacks. Here we synthesize field paired observations of particulate and mineral-associated organic carbon in the mineral layer, along with experimental warming data, to investigate whether the particulate fraction dominates in cold regions and whether this relates to higher soil organic carbon losses with warming than in other (milder) biomes. We show that soil organic carbon in the first 30cm of mineral soil is dominated or co-dominated by particulate carbon in both permafrost and non-permafrost soils, and in Arctic and alpine ecosystems but not in subarctic environments. Our findings indicate that soil organic carbon is most vulnerable to warming in cold regions compared with milder biomes, with this vulnerability mediated by higher warming-induced losses of particulate carbon. The massive soil carbon accumulation in cold regions appears distributed predominantly in the more vulnerable particulate fraction rather than in the more persistent mineral-associated fraction, supporting the likelihood of a strong, positive land carbon–climate feedback.

DOI: 10.1038/s41561-023-01354-5

Source: https://www.nature.com/articles/s41561-023-01354-5