Seasonal variations and influencing factors of dissolved organic carbon in pore water from the Dajiuhu peatland in Shennongjia
-
摘要: 亚热带泥炭地在水源涵养、碳储存和生物多样性等方面有着重要的保护价值。溶解有机碳(DOC)是泥炭地中容易受到外界扰动的一部分碳，在气候变化和人类活动的双重影响下，DOC可能通过降解或横向迁移从泥炭地中流失，潜在地威胁了泥炭地的碳储存功能。然而，目前对于亚热带泥炭地DOC如何响应季节性尺度的环境变化还缺乏深入的认识。以位于北亚热带的神农架大九湖泥炭地为研究对象，开展了季节尺度的泥炭孔隙水DOC浓度和紫外-可见吸收光谱特征以及环境参数的监测。结果显示，在大九湖泥炭地中，表层0~10 cm的泥炭孔隙水DOC浓度和光谱参数具有明显的季节差异性，DOC浓度和光谱参数还表现出明显的深度差异性。相关性分析显示，DOC浓度及紫外-可见吸收光谱参数直接受控于泥炭孔隙水的电导率和氨态氮浓度，可能还间接受到泥炭地水位和孔隙水硝态氮浓度等因素的影响。以上结果表明，在亚热带季风气候条件下，季节性水位波动引起的泥炭水化学参数和营养盐的变化，可能显著改变表层泥炭DOC动态，需要重视这种季节性波动对亚热带泥炭地碳储存能力以及生态功能的影响。Abstract: Subtropical peatlands are an important component of the global peatlands and play essential roles in water regulation, carbon storage, and biodiversity.These peatlands are being subjected to the influences of global climate changes and human disturbances.Thus, it is vital to explore how the carbon dynamics of these subtropical peatlands respond to climate changes and human activities.Dissolved organic carbon (DOC) exits as labile carbon pools that are susceptive to external environmental disturbance.Under both impacts of climate change and human activities, DOC may be lost from peatlands through degradation or horizontal migration, potentially threatening the carbon storage function of peatlands.However, knowledge about the response of DOC to seasonal environmental changes in subtropical peatlands remains poor.In this study, the seasonal variations of DOC extracted from the peat porewater along a depth profile were investigated in the Dajiuhu peatland, a typical subalpine peatland in the subtropical China.Both DOC concentration and its ultra-visible (UV-Vis) spectral indices show apparently seasonal fluctuations, while some indices also display differences among depths.Correlation analysis reveals that the DOC concentration and UV-Vis indices correlate closely with the porewater conductivity and the concentration of ammoniacal nitrogen.This study demonstrates that seasonal variation is an essential phenomenon of the carbon dynamics in the Chinese subtropical peatlands.It is urgent to quantitatively evaluate how the seasonal changes affect the carbon uptake capacity and ecosystem services of the Chinese subtropical peatlands.
-
图 1 神农架大九湖盆地地图(a)和采样点分布图(b)
Figure 1. Maps of Dajiuhu Basin (a) and the sampling sites (b)
图 3 大九湖泥炭不同深度孔隙水水化学参数季节变化
Figure 3. Seasonal variations of porewater chemistry parameters in peat pore water collected from the Dajiuhu peatland
图 4 大九湖泥炭不同深度孔隙水营养盐浓度季节变化
Figure 4. Seasonal variations of nutrient concentration of peat pore water at different depth in the Dajiuhu peatland
图 5 大九湖泥炭不同深度孔隙水DOC质量浓度(a)及UV-Vis参数(b~d)季节变化
Figure 5. Seasonal variations of DOC concentration (a) and UV-Vis ratios (b~d) in peat pore water collected from the Dajiuhu peatland
图 6 2016年大九湖泥炭孔隙水DOC与环境参数PCA分析
Figure 6. PCA analysis of environmental parameters and DOC indices in the peat pore water collected from different peat depths during 2016
表 1 泥炭孔隙水DOC质量浓度和E2/E3比值与环境参数相关性
Table 1. Correlation results among DOC concentration, E2/E3 parameters and environmental factors
DOC α254 E2/E3 SUVA254 pH ORP Cond Fe2+ NH3-N NO3-N Temp RH α254 0.96** E2/E3 -0.66** -0.62** SUVA254 -0.24 -0.10 0.14 pH -0.01 -0.09 0.20 0.16 ORP -0.32 -0.30 0.21 -0.08 -0.20 Cond 0.50** 0.38* -0.48** -0.33 0.41* -0.06 Fe2+ 0.20 0.19 -0.14 -0.08 -0.13 -0.36 0.06 NH3-N 0.46** 0.44** -0.43** -0.02 -0.10 -0.84** 0.03 0.55** NO3-N -0.19 -0.12 -0.06 0.17 -0.14 -0.55** -0.40* -0.10 0.33 Temp -0.19 -0.16 0.09 0.07 -0.22 0.92** -0.06 -0.12 -0.62** -0.51** RH 0.23 0.23 -0.26 -0.27 -0.22 -0.82** -0.01 0.14 0.50** 0.28 -0.78** DWT -0.29 -0.25 0.06 0.01 -0.14 0.86** 0.03 -0.42* -0.86** -0.26 0.73** -0.51** 注：**为p < 0.01; *为p < 0.05；ORP.氧化还原电位；Cond.电导率；Temp.气温；RH.相对湿度；DWT.沼泽水位埋深 
下载: 导出CSV
-
[1] Gorham E. Northern peatlands: Role in the carbon cycle and probable responses to climatic warming[J]. Ecological Applications, 1991, 1(2): 182-195. doi: 10.2307/1941811 [2] Yu Z. Holocene carbon flux histories of the world's peatlands: Global carbon-cycle implications[J]. The Holocene, 2011, 21(5): 761-774. doi: 10.1177/0959683610386982 [3] Dinsmore K J, Billett M F, Skiba U M, et al. Role of the aquatic pathway in the carbon and green house gas budgets of a peatland catchment[J]. Global Change Biology, 2010, 16(10): 2750-2762. doi: 10.1111/j.1365-2486.2009.02119.x [4] 廖婷, 邢新丽, 石明明, 等. 神农架大九湖PAHs多介质归趋模拟[J]. 地质科技通报, 2020, 39(5): 148-155. http://dzkjqb.cug.edu.cn/CN/abstract/abstract10060.shtml [5] Moore S, Evans C D, Page S E, et al. Deep instability of deforested tropical peatlands revealed by fluvial organic carbon fluxes[J]. Nature, 2013, 493: 660-663. doi: 10.1038/nature11818 [6] Guo Y, Wan Z, Liu D. Dynamics of dissolved organic carbon in the mires in the Sanjiang Plain, Northeast China[J]. Journal of Environmental Sciences, 2010, 22(1): 84-90. doi: 10.1016/S1001-0742(09)60078-4 [7] J, Kaštovskš E, Bárta J, et al. Qualify of DOC produced during litter decomposition of peatland plant dominants[J]. Soil Biology and Biochemistry, 2018, 121: 221-230. doi: 10.1016/j.soilbio.2018.03.018 [8] Kang H, Kwon M J, Kim S, et al. Biologically driven DOC release from peatlands during recovery from acidification[J]. Nature Communications, 2018, 9: 3807. doi: 10.1038/s41467-018-06259-1 [9] Fenner N, Freeman C. Drought-induced carbon loss in peatlands[J]. Nature Geoscience, 2011, 4(12): 895-900. doi: 10.1038/ngeo1323 [10] Yang G, Wang M, Chen H, et al. Responses of CO2 emission and pore water DOC concentration to soil warming and water table drawdown in Zoigê Peatlands[J]. Atmospheric Environment, 2017, 152: 323-329. doi: 10.1016/j.atmosenv.2016.12.051 [11] Weishaar J L, Aiken G R, Bergamaschi B A, et al. Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon[J]. Environmental Science & Technology, 2003, 37(20): 4702-4708. http://www.tandfonline.com/servlet/linkout?suffix=CIT0027&dbid=8&doi=10.1080%2F01919512.2018.1444977&key=14594381 [12] Cook S, Peacock M, Evans C D, et al. Quantifying tropical peatland dissolved organic carbon (DOC) using UV-visible spectroscopy[J]. Water Research, 2017, 115: 229-235. doi: 10.1016/j.watres.2017.02.059 [13] Pickard A E, Heal K V, McLeod A R, et al. Temporal changes in photoreactivity of dissolved organic carbon and implications for aquatic carbon fluxes from peatlands[J]. Biogeosciences, 2017, 14: 1793-1809. doi: 10.5194/bg-14-1793-2017 [14] Zhang Y, Shi F, Mao R. Alnus sibirica encroachment promotes dissolved organic carbon biodegradation in a boreal peatland[J]. Science of the Total Environment, 2019, 695: 133882. doi: 10.1016/j.scitotenv.2019.133882 [15] Wang X, Huang X, Sachse D, et al. Molecular paleoclimate reconstructions over the last 9 ka from a peat sequence in South China[J]. PLoS ONE, 2016, 11(8): e0160934. doi: 10.1371/journal.pone.0160934 [16] Zhong W, Xue J, Ouyang J, et al. Evidence of Late Holocene climate variability in the western Nanling Mountains, South China[J]. Journal of Paleolimnology, 2014, 52(1/2): 1-10. doi: 10.1007/s10933-014-9774-6 [17] 汪正祥, 雷耘, 刘胜祥, 等. 湖北七姊妹山自然保护区发现亚高山泥炭藓湿地[J]. 华中师范大学学报: 自然科学版, 2005, 39(3): 387-388. doi: 10.3321/j.issn:1000-1190.2005.03.023 [18] 秦养民, 巩静, 顾延生, 等. 鄂西亚高山泥炭地有壳变形虫生态监测及对水位的指示意义[J]. 地球科学, 2018, 43(11): 4036-4045. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201811021.htm [19] 顾延生, 唐倩倩, 刘红叶, 等. 浙江景宁亚高山湿地群形成环境探究[J]. 湿地科学, 2016, 14(3): 302-310. https://www.cnki.com.cn/Article/CJFDTOTAL-KXSD201603003.htm [20] 赵素婷, 厉恩华, 王学雷, 等. 鄂西亚高山泥炭藓沼泽湿地高等植物多样性研究[J]. 长江流域资源与环境, 2013, 22(4): 468-475. https://www.cnki.com.cn/Article/CJFDTOTAL-CJLY201304013.htm [21] 韩爱艳, 曾砺锋, 黄康有, 等. 罗霄山脉山地沼泽全新世以来的古气候记录[J]. 热带地理, 2016, 36(3): 477-485. https://www.cnki.com.cn/Article/CJFDTOTAL-RDDD201603018.htm [22] 赵魁义. 中国沼泽志[M]. 北京: 科学出版社, 1999. [23] 潘超, 刘林峰, 高健, 等. 神农架大九湖后生浮游动物群落结构和水质评价[J]. 长江流域资源与环境, 2018, 27(3): 564-573. doi: 10.11870/cjlyzyyhj201803012 [24] 黄咸雨, 张志麒, 王红梅, 等. 神农架大九湖泥炭湿地关键带监测进展[J]. 地球科学, 2017, 42(6): 1026-1038. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201706012.htm [25] 罗涛, 伦子健, 顾延生, 等. 神农架大九湖湿地植物群落调查与生态保护研究[J]. 湿地科学, 2015, 13(2): 153-160. https://www.cnki.com.cn/Article/CJFDTOTAL-KXSD201502003.htm [26] 王东香, 张一鸣, 王锐诚, 等. 神农架大九湖泥炭地孔隙水溶解有机碳特征及其影响因素[J]. 长江流域资源与环境, 2018, 27(11): 2568-2577. https://www.cnki.com.cn/Article/CJFDTOTAL-CJLY201811018.htm [27] 哈希公司. 水质分析实用手册[M]. 第2版. 北京: 化学工业出版社, 2016. [28] Grayson R, Holden J. Continuous measurement of spectro photometric absorbance in peatland stream water in northern England: Implications for understanding fluvial carbon fluxes[J]. Hydrological Processes, 2012, 26(1): 27-39. doi: 10.1002/hyp.8106 [29] Huang X, Meyers P A. Assessing paleohydrologic controls on the hydrogen isotope compositions of leaf wax n-alkanes in Chinese peat deposits[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2019, 516: 354-363. doi: 10.1016/j.palaeo.2018.12.017 [30] 何报寅. 神农架大九湖泥炭的环境变化记录[M]. 武汉: 中国地质大学出版社, 2007 [31] 冯宝飞, 张涛, 曾明. 2016年秋长江中下游枯水分析及对水库调度的启示[J]. 人民长江, 2018, 49(11): 9-13. https://www.cnki.com.cn/Article/CJFDTOTAL-RIVE201811003.htm [32] Zhao B, Zhang Y, Huang X, et al. Comparison of n-alkane molecular, carbon and hydrogen isotope compositions of different types of plants in the Dajiuhu Peatland, Central China[J]. Organic Geochemistry, 2018, 124: 1-11. doi: 10.1016/j.orggeochem.2018.07.008 [33] 万翔, 向武, 邬钰, 等. 高原泥炭沼泽区高浓度溶解性铁的成因研究[J]. 环境科学与技术, 2013, 36(11): 7-11. https://www.cnki.com.cn/Article/CJFDTOTAL-FJKS201311002.htm [34] 娄雪冬, 翟生强, 康冰, 等. 若尔盖泥炭地溶解有机碳季节变化特征及其影响因素[J]. 环境科学研究, 2014, 27: 157-163. https://www.cnki.com.cn/Article/CJFDTOTAL-HJKX201402007.htm [35] 杨文燕, 宋长春, 张金波. 沼泽湿地孔隙水中溶解有机碳、氮浓度季节动态及与甲烷排放的关系[J]. 环境科学学报, 2006, 26(10): 1745-1750. doi: 10.3321/j.issn:0253-2468.2006.10.026 [36] De Haan H. Solar UV-light penetration and photode gradation of humic substances in peaty lake water[J]. Limnology and Oceanography, 1993, 38(5): 1072-1076. doi: 10.4319/lo.1993.38.5.1072 [37] García C, Hernández T, Costa F. Microbial activity in soils under Mediterranean environmental conditions[J]. Soil Biology & Biochemistry, 1994, 26(9): 1185-1191. http://europepmc.org/abstract/AGR/IND20433313 [38] Adviento-Borbe M A A, Doran J W, Drijber R A, et al. Soil electrical conductivity and water content affect nitrous oxide and carbon dioxide emissions in intensively managed soils[J]. Journal of Environmental Quality, 2006, 35(6): 1999-2010. doi: 10.2134/jeq2006.0109 [39] 崔敏, 冉炜, 沈其荣. 水溶性有机质对土壤硝化作用过程的影响[J]. 生态与农村环境学报, 2006, 22(3): 45-50. doi: 10.3969/j.issn.1673-4831.2006.03.013 [40] Dorrepaal E, Toet S, van Logtestijin R S L, et al. Carbon respiration from subsurface peat accelerated by climate warming in the subarctic[J]. Nature, 2009, 460: 616-619. doi: 10.1038/nature08216 [41] Clark J M, Chapman P J, Adamson J K, et al. Influence of drought-induced acidification on the mobility of dissolved organic carbon in peat soils[J]. Global Change Biology, 2005, 11: 791-809. doi: 10.1111/j.1365-2486.2005.00937.x [42] 张晓雅, 胡益珩, 安菁, 等. 若尔盖泥炭沼泽土壤中可溶性有机碳含量对降水变化的响应[J]. 湿地科学, 2018, 16(4): 546-551. https://www.cnki.com.cn/Article/CJFDTOTAL-KXSD201804014.htm [43] Wang R C, Wang H M, Xiang X, et al. Temporal and spatial variations of microbial carbon utilization in water bodies from the Dajiuhu Peatland, Central China[J]. Journal of Earth Science, 2018, 29(4): 969-976. doi: 10.1007/s12583-017-0818-5 [44] Xiang X, Wang H M, Gong L F, et al. Vertical variations and associated ecological function of bacterial communities from Sphagnum to underlying sediments in Dajiuhu Peatland[J]. Science China: Earth Science, 2014, 57(5): 1013-1020. doi: 10.1007/s11430-013-4752-9 [45] Xu Ying, Wang Hongmei, Xiang Xing, et al. Vertical variation of nitrogen fixers and ammonia oxidizers along a sediment profile in the Dajiuhu Peatland, Central China[J]. Journal of Earth Science, 2019, 30(2): 397-406. doi: 10.1007/s12583-018-0982-2 [46] Tian W, Wang H, Xiang X, et al. Structural variations of bacterial community driven by Sphagnum microhabitat differentiation in a subalpine peatland[J]. Fronters in Microbiology, 2019, 10: 10661. http://www.researchgate.net/publication/334653852_Structural_Variations_of_Bacterial_Community_Driven_by_Sphagnum_Microhabitat_Differentiation_in_a_Subalpine_PeatlandData_Sheet_1docx [47] 张晶, 刘运德, 周爱国, 等. 硝酸盐污染地下水中溶解性有机质光谱特征及其指示意义: 以鄂尔多斯盆地北部湖泊集中区为例[J]. 地质科技情报, 2019, 38(4): 262-269. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ201904028.htm -
下载:
点击查看大图
图(6) / 表(1)
计量
- 文章访问数: 613
- PDF下载量: 857
- 被引次数: 0
