不同冻结温度黑土渐次解冻过程有机碳矿化特征及影响因素

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (958 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要将粒径<2mm的黑土填充土柱后，湿润至田间持水量（41%），分别在-10℃、-15℃和-20℃冷冻12h，于10℃解冻.为捕捉土壤水盐养分在土柱由外而内冻结过程中的再分布特征，在土柱渐次解冻过程中从外到内逐层剥离成六层（T1~T6），并进行指标测定.结果表明：1）土柱最外层T1的含水率最高达48.9%~61.9%，而内核T6最干燥仅为29.3%~35%，其中-20℃冻结土柱在解冻后外层的水分富集程度最显著.电导率（EC）则表现为外层T1和内层T6偏高（53.9~66.4μS/cm和55.0~64.0μS/cm），而中间层T3偏低（53~56.5μS/cm），且-10℃冻结后各渐次解冻土层间的EC差异最显著.2）可溶性有机碳（DOC）由外层T1向内层T6逐渐降低，而微生物生物量碳（SMBC）则由外层向内层呈现增多趋势，且冻结温度越低，DOC和SMBC在各解冻土层间的差异越明显.3） CO₂释放速率表现为外层T1和内层T6较高（34~40.7μg/g和33.5~63μg/g），而中间层T4较低（23.7~25.0μg/g），且-10℃冻结后各渐次解冻土层释放的CO₂显著少于-20℃冻结温度.4）各解冻土层SMBC与DOC线性负相关，但与CO₂释放速率线性正相关，说明冻结过程死亡微生物残体释放的可溶性物质，可促进存活微生物在土壤解冻后的呼吸过程.本研究通过逐层剥离方法可有效捕捉土壤冻融过程两极化分布对碳矿化的影响，而不同冻结温度则加剧了渐次解冻土层间的异质性，突破了仅基于全冻全融过程的传统研究方法对土壤冻融环境效应认识的片面性.

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	刘会敏
	宋媛
	栗现文
	胡亚鲜

关键词 ：冻融, 温度, 水盐, 微生物, CO₂排放

Abstract：The process of soil freezing and thawing, due to the severe changes of temperature and the two-phase transformation of ice and water, can profoundly reorganize the spatial distribution pattern of water, salt, nutrients and microorganisms within the soil matrix. The freezing temperature determines the structure and migration rate of the freezing front, which consequently affects the migration and diffusion efficiency of water, salt and nutrients and hence perturbs soil organic carbon mineralization. In this study, a mollisol (particle size < 2mm) was re-filled into soil columns, rewetted to field capacity (41%), respectively frozen at -10℃, -15℃ and -20℃ for 12h, and then thawed at 10℃. Individual soil columns were gradually peeled from the outside to the inner core into six layers (T1~T6) while progressively thawing, to capture the redistribution patterns of soil water, salt and nutrients during freeze-thaw. The results show that:1) The outmost layer T1had the highest water content (48.9%~61.9%), but the inner core T6 was drier with the lowest water content (29.3%~35%), and such polarized distributions of moisture were most significant in the soil columns frozen at -20℃. On the contrary, the electrical conductivity (EC) was higher in the outer layer T1and inner layer T6 (53.9~66.4μS/cm and 55.0~64.0μS/cm), but lowest in the middle layer T3 (53~56.5μS/cm). The difference of EC among the soil layers was most significant for the soil column frozen at -10℃. 2) The dissolved organic carbon (DOC) gradually decreased, but the soil microbial biomass carbon (SMBC) increased, from the outer layer T1to the inner core T6. Such patterns were more pronounced when the soil columns experienced lower freezing temperature. 3) The CO₂ emission rate was higher in the outer layer T1 and inner core T6 (34~40.7μg/g and 33.5~63μg/g), but lower in the middle layer T4 (23.7~25.0μg/g). The soil columns after frozen at -10℃ released significantly less CO₂ than those frozen at -20℃. 4) The SMBC was negatively linearly correlated with DOC, but positively linearly correlated with CO₂ emission rate, suggesting that freezing can neutralize microbes, and the thus released dissolved nutrients can promote the survived microbes to respire during thawing. Our findings show that, peeling off the progressively thawed soil layers from the frozen core can effectively capture the polarized distribution of biophysiochemical properties and the potential impacts on carbon mineralization. Different freezing temperatures regulated the inter-layer heterogeneity over progressive thawing, further pointing to the limitation and thus partial understanding of freeze-thaw impacts on soil carbon mineralization if merely based on conventional investigations after complete thawing.

Key words： freeze-thaw temperature water-salt soil microbes CO₂ emissions

收稿日期: 2022-07-07

PACS:

X142

基金资助:中国科学院“西部之光”人才培养计划“西部青年学者”项目（XAB2020YN03）；中国博士后科学基金（2020M673518）；中央高校基本科研业务费专项资金资助（2452020338）

通讯作者: 胡亚鲜,副研究员,huyaxian@nwafu.edu.cn E-mail: huyaxian@nwafu.edu.cn

作者简介: 刘会敏(1997-),女,河南周口人,西北农林科技大学硕士研究生,主要从事冻融对碳排放影响方面的研究.

引用本文:

刘会敏, 宋媛, 栗现文, 胡亚鲜. 不同冻结温度黑土渐次解冻过程有机碳矿化特征及影响因素[J]. 中国环境科学, 2023, 43(3): 1288-1297. LIU Hui-min, SONG Yuan, LI Xian-wen, HU Ya-xian. Influences of freezing temperature on the inter-layer variations of mollisol organic carbon mineralization over progressive thawing. CHINA ENVIRONMENTAL SCIENCECE, 2023, 43(3): 1288-1297.

链接本文:

http://www.zghjkx.com.cn/CN/ 或 http://www.zghjkx.com.cn/CN/Y2023/V43/I3/1288

[1]	范昊明,张瑞芳,周丽丽,等.气候变化对东北黑土冻融作用与冻融侵蚀发生的影响分析[J]. 干旱区资源与环境, 2009,23(6):48-53. Fan H M, Zhang R F, Zhou L L, et al. Impact of climate change on freeze-thaw function and freeze-thaw erosion in black soil region of Northeast China[J]. Journal of Arid Land Resources and Environment, 2009,23(6):48-53.
[2]	刘宝元,阎百兴,沈波,等.东北黑土区农地水土流失现状与综合治理对策[J]. 中国水土保持科学, 2008,6(1):1-8. Liu B Y, Yan B X, S B, et al. Current status and comprehensive control strategies of soil erosion for cultivated land in the Northeastern black soil area of China[J]. Science of Soil and Water Conservation, 2008,6(1):1-8.
[3]	刘兴土,阎百兴.东北黑土区水土流失与粮食安全[J]. 中国水土保持, 2009,(1):17-19.
[4]	Liu B, Fan H, Han W, et al. Linking soil water retention capacity to pore structure characteristics based on X-ray computed tomography:Chinese Mollisol under freeze-thaw effect[J]. Geoderma, 2021,401:115170.
[5]	Chen S, Burras C L, Zhang X. Soil aggregate response to three freeze-thaw methods in a Northeastern China Mollisol[J]. Polish Journal of Environmental Studies, 2019,28(5):3635-3645.
[6]	Wang L, Zuo X, Zheng F, et al. The effects of freeze-thaw cycles at different initial soil water contents on soil erodibility in Chinese Mollisol region[J]. Catena, 2020,193:104615.
[7]	Schindlbacher A, Jandl R, Schindlbacher S. Natural variations in snow cover do not affect the annual soil CO2 efflux from a mid-elevation temperate forest[J]. Global Change Biology, 2014,20(2):622-632.
[8]	Gao D, Liu Z, Bai E. Effects of in situ freeze-thaw cycles on winter soil respiration in mid-temperate plantation forests[J]. Science of The Total Environment, 2021,793:148567.
[9]	Qin Y, Bai Y, Chen G, et al. The effects of soil freeze-thaw processes on water and salt migrations in the western Songnen Plain, China[J]. Scientific Reports, 2021,11(1):1-12.
[10]	Zhang J, Lai Y, Li J, et al. Study on the influence of hydro-thermal-salt-mechanical interaction in saturated frozen sulfate saline soil based on crystallization kinetics[J]. International Journal of Heat and Mass Transfer, 2020,146:118868.
[11]	Huang H, Chen C, Mo X, et al. Mechanisms of salt rejection at the ice-liquid interface during the freezing of pore fluids in the seasonal frozen soil area[J]. China Geology, 2021,4(3):449-457.
[12]	孙嘉鸿,郭彤,董彦民,等.冻融循环对金川泥炭沼泽土壤微生物量及群落结构的影响[J]. 生态学报, 2022,42(7):2763-2773. Sun H J, Guo T, Dong Y M, et al. Effect of freezing and thawing on soil microbial biomass and community structure in Jinchuan peatlands[J]. Acta Ecologica Sinica, 2022,42(7):2763-2773.
[13]	Ma Q, Zhang K, Jabro J D, et al. Freeze-thaw cycles effects on soil physical properties under different degraded conditions in Northeast China[J]. Environmental Earth Sciences, 2019,78(10):1-12.
[14]	Rooney E C, Bailey V L, Patel K F, et al. Soil pore network response to freeze-thaw cycles in permafrost aggregates[J]. Geoderma, 2022, 411:115674.
[15]	Sorensen P O, Templer P H, Finzi A C. Contrasting effects of winter snowpack and soil frost on growing season microbial biomass and enzyme activity in two mixed-hardwood forests[J]. Biogeochemistry, 2016,128(1/2):141-154.
[16]	阳祥,黄晓婷,王纯,等.典型稻田土壤真菌群落结构及多样性对比[J]. 中国环境科学, 2020,40(10):4549-4556. Yang X, Huang X T, Wang C, et al. Comparison of fungal community structure and diversity in typical paddy fields.[J]. China Environmental Science, 2020,40(10):4549-4556.
[17]	King A E, Rezanezhad F, Wagner-Riddle C. Evidence for microbial rather than aggregate origin of substrates fueling freeze-thaw induced N2O emissions[J]. Soil Biology and Biochemistry, 2021,160:108352.
[18]	Watanabe K, Mizoguchi M. Amount of unfrozen water in frozen porous media saturated with solution[J]. Cold Regions Science and Technology, 2002,34(2):103-110.
[19]	Bing H, He P, Zhang Y. Cyclic freeze-thaw as a mechanism for water and salt migration in soil[J]. Environmental Earth Sciences, 2015, 74(1):675-681.
[20]	Zhang J, Hong J, Wei D, et al. Severe freezing increases soil respiration during the thawing period:A meta-analysis[J]. European Journal of Soil Science, 2022,73(1):e13161
[21]	Ren J, Song C, Hou A, et al. Shifts in soil bacterial and archaeal communities during freeze-thaw cycles in a seasonal frozen marsh, Northeast China[J]. Science of The Total Environment, 2018,625:782-791.
[22]	张科利,刘宏远.东北黑土区冻融侵蚀研究进展与展望[J]. 中国水土保持科学, 2018,16(1):17-24. Zhang K L, Liu H Y. Research progresses and prospects on freeze-thaw erosion in the black soil region of Northeast China[J]. Science of Soil and Water Conservation, 2018,16(1):17-24.
[23]	鲁如坤.土壤农业化学分析方法[M]. 中国农业科技出版社, 2000. Lu R K. Soil Agricultural chemical analysis methods[M]. China Agricultural Science and Technology Press, 2000.
[24]	Huiru J, Wenjiang Z, Yi Y, et al. The impacts of soil freeze/thaw dynamics on soil water transfer and spring phenology in the Tibetan Plateau[J]. Arctic, Antarctic, and Alpine Research, 2018,50(1):e1439155.
[25]	吴刚,邴慧,卜东升.盐渍土与盐溶液冻结温度关系的试验研究[J]. 冰川冻土, 2019,41(3):615-628. Wu G, Bing H, Bu D S. Experimental study on the relationship between saline soil and salt solution freezing temperature[J]. Journal of Glaciology and Geocryology, 2019,41(3):615-628.
[26]	Wan X, Gong F, Qu M, et al. Experimental study of the salt transfer in a cold sodium sulfate soil[J]. Ksce Journal of Civil Engineering, 2019,23(4):1573-1585.
[27]	Wu H, Xu X, Cheng W, et al. Antecedent soil moisture prior to freezing can affect quantity, composition and stability of soil dissolved organic matter during thaw[J]. Scientific Reports, 2017,7(1):6312-6380.
[28]	Hu Y, Li X, Liu H, et al. Progressively thawed soil layers differed in microbial properties and CO2 emission rates[J]. Catena, 2023,221:106791.
[29]	Hou R, Li T, Fu Q, et al. Characteristics of water-heat variation and the transfer relationship in sandy loam under different conditions[J]. Geoderma, 2019,340:259-268.
[30]	徐爽,郭颖,单炜.冻融过程中重塑土水盐迁移的试验研究[J]. 科学技术与工程, 2017,17(30):285-290. Xu S, Guo Y, Shan W. Experimental study on migration and salinity of remolded soil during freezing and thawing[J]. Science Technology and Engineering, 2017,17(30):285-290.
[31]	Tang R, Zhou G, Jiao W, et al. Theoretical model of hydraulic conductivity for frozen saline/non-saline soil based on freezing characteristic curve[J]. Cold Regions Science and Technology, 2019, 165:102794.
[32]	Hou R, Li T, Fu Q, et al. Research on the distribution of soil water, heat, salt and their response mechanisms under freezing conditions[J]. Soil and Tillage Research, 2020,196:104486.
[33]	Haei M, Rousk J, Ilstedt U, et al. Effects of soil frost on growth, composition and respiration of the soil microbial decomposer community[J]. Soil Biology and Biochemistry, 2011,43(10):2069-2077.
[34]	Watanabe T, Tateno R, Imada S, et al. The effect of a freeze-thaw cycle on dissolved nitrogen dynamics and its relation to dissolved organic matter and soil microbial biomass in the soil of a northern hardwood forest[J]. Biogeochemistry, 2019,142(3):319-338.
[35]	Liu F, Jiao X, Wang S, et al. Heat, water and vapor coupled migration in loess under uniaxial freezing condition[J]. Cold Regions Science and Technology, 2022,198:103550.
[36]	Foster A, Jones D L, Cooper E J, et al. Freeze-thaw cycles have minimal effect on the mineralisation of low molecular weight, dissolved organic carbon in Arctic soils[J]. Polar Biology, 2016,39(12):2387-2401.
[37]	刘淑霞,王宇,赵兰坡,等.冻融作用下黑土有机碳数量变化的研究[J]. 农业环境科学学报, 2008,(3):984-990. Liu S X, Wang Y, Zhao L B, et al. Effect of freezing and thawing on the content of organic carbon of black soil[J]. Journal of Agro-Environment Science, 2008,(3):984-990.
[38]	王旭,李斐,赵世翔.冻融交替对土壤CO2排放影响的研究进展[J]. 土壤通报, 2022,53(3):728-737. Wang X, Li F, Zhao S X. Freeze-thaw regime effects on soil CO2 emission:A review[J]. Chinese Journal of Soil Science, 2022,53(3):728−737.
[39]	Oztas T, Fayetorbay F. Effect of freezing and thawing processes on soil aggregate stability[J]. Catena, 2003,52(1):1-8.
[40]	赵光影,郭冬楠,江姗,等.冻融作用对小兴安岭典型湿地土壤活性有机碳的影响[J]. 生态学报, 2017,37(16):5411-5417. Zhao G Y, Guo D N, Jiang S, et al. Effects of freezing and thawing on soil active organic carbon in the Xiaoxing'an Mountain wetlands[J]. Acta Ecologica Sinica, 2017,37(16):5411-5417.
[41]	Wei W, You W, Zhang H, et al. Soil respiration during freeze-thaw cycles in a temperate Korean Larch (Larix olgensis herry.) plantation[J]. Scandinavian Journal of Forest Research, 2016,31(8):742-749.
[42]	Wei X, Huang C, Wei N, et al. The impact of freeze-thaw cycles and soil moisture content at freezing on runoff and soil loss[J]. Land Degradation and Development, 2019,30(5):515-523.