大兴安岭多年冻土区森林土壤有机碳分子特征及土壤矿化温度敏感性

doi:10.13287/j.1001-9332.202601.020

摘要/Abstract

摘要： 作为中国第二大冻土碳库,大兴安岭多年冻土区土壤有机碳(SOC)稳定性对全球气候变化具有重要调控作用。为揭示该区域SOC分子特征及与矿化过程的关联机制,本研究采集不连续多年冻土区和岛状多年冻土区表层(0～10 cm)森林土壤样品,利用傅里叶变换衰减红外光谱(FTIR)解析SOC官能团组成及分子多样性,并通过室内培养试验(10和20 ℃,持续9周)观测SOC矿化动态,进而探究其温度敏感性(Q₁₀)与分子特征的耦合关系。结果表明: SOC官能团组成及分子多样性在空间上分异显著,且受多年冻土类型主导。不连续多年冻土区的芳香族(C=C、COO-)及烷烃类(C-H)含量显著高于岛状多年冻土区,而醇和酚类(O-H)含量则显著低于后者;不连续多年冻土区SOC分子多样性亦显著更高,且多样性与土壤pH和最大持水量(WHC)显著相关。增温显著促进多年冻土SOC矿化,20 ℃下的累积矿化量较10 ℃增加2.1～2.3倍;大兴安岭多年冻土区Q₁₀值介于1.1～1.9,并与易分解组分[脂肪族(C-H)、酰胺类(N-H)]含量呈显著正相关,表明活性碳库的快速响应是驱动温度敏感性的关键。本研究首次阐明了大兴安岭冻土SOC分子特征与温度敏感性的区域耦合规律,为精准评估该区域冻土碳-气候反馈潜力提供了分子尺度的理论依据。

关键词: 大兴安岭多年冻土, SOC分子组成, 分子多样性, 温度敏感性, 红外光谱

Abstract: As the second largest permafrost carbon reservoir in China, the stability of soil organic carbon (SOC) in the permafrost region of the Greater Khingan Moutains plays an important role in regulating climate change. To reveal the molecular characteristics of SOC and their influence on mineralization process, we collected surface soil samples (0-10 cm) from both the discontinuous and sporadic permafrost zones. Soil organic carbon molecular composition and diversity were characterized using Fourier transform attenuated infrared (FTIR) spectroscopy. SOC mineralization dynamics at 10 ℃ and 20 ℃ were examined with a 9-week laboratory incubation experiment. We further explored the coupling relationship between temperature sensitivity (Q₁₀) and molecular characteristics. The results showed that: SOC functional group composition and molecular diversity showed significant spatial heterogeneity, primarily governed by permafrost type. The discontinuous permafrost zone exhibited significantly higher abundances of aromatic (C=C, COO-) and alkyl (C-H) groups but a lower abundance of alcohol and phenol (O-H) groups compared to the sporadic permafrost zone. Molecular diversity was significantly higher in the discontinuous zone and was correlated with soil pH and water holding capacity (WHC). Warming significantly enhanced SOC mineralization, with cumulative mineralization at 20 ℃ being 2.1-2.3 times greater than that at 10 ℃. The Q₁₀ values ranged from 1.1 to 1.9, and showed significant positive correlations with labile components, such as aliphatic (C-H) and amide (N-H) groups. Those results indicated that the rapid response of these active carbon pools was key to driving temperature sensitivity. Through elucidating the regional coupling between SOC molecular characteristics and temperature sensitivity in the permafrost of the Greater Khingan Mountains, our results offer a molecular-scale theoretical basis for accurately assessing the permafrost carbon-climate feedback potential.

Key words: permafrost in the Greater Khingan Mountains, SOC molecular composition, molecular diversity, temperature sensitivity, infrared spectroscopy

孙海铭, 霍常富, 阴黎明, 何杨辉, 王朋. 大兴安岭多年冻土区森林土壤有机碳分子特征及土壤矿化温度敏感性[J]. 应用生态学报, 2026, 37(2): 399-408.

SUN Haiming, HUO Changfu, YIN Liming, HE Yanghui,WANG Peng. Molecular characteristics of soil organic carbon and temperature sensitivity of soil respiration in the permafrost forest region of the Greater Khingan Mountains, Northeast China[J]. Chinese Journal of Applied Ecology, 2026, 37(2): 399-408.

参考文献

[1] 周幼吾. 中国冻土. 北京: 科学出版社, 2000
[2] 马蔷, 金会军. 气候变暖对多年冻土区土壤有机碳库的影响. 冰川冻土, 2020, 42(2): 91-103
[3] 徐嘉晖, 孙颖, 高雷, 等. 土壤有机碳稳定性影响因素的研究进展. 生态农业学报, 2018, 26(2): 222-230
[4] Cheng F, Garzione C, Li XZ, et al. Alpine permafrost could account for a quarter of thawed carbon based on Plio-Pleistocene paleoclimate analogue. Nature Communications, 2022, 13: 1329
[5] Jones AR, Dalal RC, Gupta WSR, et al. Molecular complexity and diversity of persistent soil organic matter. Soil Biology and Biochemistry, 2023, 184: 109061
[6] Czimczik CI, Preston CM, Schmidt MWI, et al. How surface fire in Siberian Scots pine forests affects soil organic carbon in the forest floor: Stocks, molecular structure, and conversion to black carbon (charcoal). Global Biogeochemical Cycles, 2003, 17: 1020
[7] Ran YH, Li X, Cheng GD, et al. New high-resolution estimates of the permafrost thermal state and hydrothermal conditions over the Northern Hemisphere. Earth System Science Data, 2022, 14: 865-884
[8] Öquist MG, Erhagen B, Haei M, et al. The effect of temperature and substrate quality on the carbon use efficiency of saprotrophic decomposition. Plant and Soil, 2017, 414: 113-125
[9] Bosatta E, Agren GI. Soil organic matter quality interpreted thermodynamically. Soil Biology and Biochemistry, 1999, 31: 1889-1891
[10] Qin SQ, Kou D, Mao C, et al. Temperature sensitivity of permafrost carbon release mediated by mineral and microbial properties. Science Advances, 2021, 7: eabe3596
[11] Wang K, Bastos A, Ciais P, et al. Regional and seasonal partitioning of water and temperature controls on global land carbon uptake variability. Nature Communications, 2022, 13: 3469
[12] Xu CH, Guo LD, Ping CL, et al. Chemical and isotopic characterization of size-fractionated organic matter from cryoturbated tundra soils, northern Alaska. Journal of Geophysical Research, 2009, 114: G03002
[13] Jones DL, Hill PW, Smith AR, et al. Role of substrate supply on microbial carbon use efficiency and its role in interpreting soil microbial community-level physiological profiles (CLPP). Soil Biology and Biochemistry, 2018, 123: 1-6
[14] 董星丰, 陈强, 臧淑英, 等. 温度和水分对大兴安岭多年冻土区森林土壤有机碳矿化的影响. 环境科学学报, 2019, 39(12): 4269-4275
[15] 朱雪峰, 张春雨, 郝艳杰, 等. 玉米秸秆覆盖还田量对免耕土壤有机碳中红外光谱特征的影响. 应用生态学报, 2021, 32(8): 2685-2692
[16] Viscarra RA, Jeon YS, Odeh I, et al. Using a legacy soil sample to develop a mid-IR spectral library. Austra-lian Journal of Soil Research, 2008, 46: 1-16
[17] Janik LJ, Skjemstad JO, Shepherd KD, et al. The prediction of soil carbon fractions using mid-infrared-partial least square analysis. Australian Journal of Soil Research, 2007, 45: 73e81
[18] Bornemann L, Welp G, Amelung W. Particulate organic matter at the field scale: Rapid acquisition using mid-infrared spectroscopy. Soil Science Society of America Journal, 2010, 74: 1147-1156
[19] Jones AR, Dalal RC, Gupta SR, et al. Molecular complexity and diversity of persistent soil organic matter. Soil Biology and Biochemistry, 2023, 184: 109061
[20] Davidson EA, Trumbore SE, Amundson R. Soil warming and organic carbon content. Nature, 2000, 408: 789-790
[21] 陈珊珊, 臧淑英, 孙丽. 东北多年冻土退化及环境效应研究现状与展望. 冰川冻土, 2018, 40(2): 298-306
[22] Roth VN, Dittmar T, Gaupp R, et al. The molecular composition of dissolved organic matter in forest soils as a function of pH and temperature. PLoS One, 2015, 10: e0119188
[23] Grandy AS, Neff JC, Weintrau MN, et al. Carbon structure and enzyme activities in alpine and forest ecosystems. Soil Biology and Biochemistry, 2007, 39: 2701-2711
[24] 王洋, 刘景双, 王全英. 冻融作用对土壤团聚体及有机碳组分的影响. 生态环境学报, 2013, 22(7): 1269-1274
[25] Ingrosso G, Ceccarelli C, Giglio F, et al. Greening of Svalbard in the twentieth century driven by sea ice loss and glaciers retreat. Communications Earth & Environment, 2025, 6: 30
[26] Bai XJ, Zhai GQ, Yan ZF, et al. Effects of microbial groups on soil organic carbon accrual and mineralization during high- and low-quality litter decomposition. Catena, 2024, 241: 108051
[27] 郭晓伟, 张雨雪, 尤业明, 等. 凋落物输入对森林土壤有机碳转化与稳定性影响的研究进展. 应用生态学报, 2024, 35(9): 2352-2361
[28] Kleber M, Eusterhues K, Keiluweit M, et al. Mineral-organic associations: Formation, properties, and relevance in soil environments. Advances in Agronomy, 2015, 130: 1-140
[29] Davidson EA, Janssens IA. Temperature sensitivity of soil carbon decomposition and feedbacks to climate change. Nature, 2006, 440: 165-173
[30] Bosatta E, Agren GI. Theoretical-analysis of microbial biomass dynamics in soils. Soil Biology and Biochemistry, 1994, 26: 143-148
[31] Chen QY, Niu B, Hu YL. Warming and increased precipitation indirectly affect the composition and turnover of labile-fraction soil organic matter by directly affecting vegetation and microorganisms. Science of the Total Environment, 2020, 714: 136787
[32] Wu HB, Guo ZT, Peng CH. Land use induced changes of organic carbon storage in soils of China. Global Change Biology, 2003, 9: 305-315
[33] 刘和斌, 母梅, 牟翠翠, 等. IPCC第六次评估报告解读: 北半球多年冻土碳的观测结果和预估. 冰川冻土, 2023, 45(2): 318-326
[34] 孙瑞丰, 韩广轩. 模拟增温对土壤有机碳含量、组分和化学结构的影响: 进展与展望. 应用生态学报, 2024, 35(9): 2432-2444