Sources, preservation, and influencing factors of organic carbon from the Dagu River Basin
HUANG Tie-han1,2, LIU Ke3, LI Li1,2, XIAO Xiao-tong1,2
1. Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; 2. Laoshan Laboratory, Qingdao 266237, China; 3. National Marine Environmental Monitoring Center, Dalian 116023, China
Abstract:In this study, surface water, suspended particulate matters and sediments were collected in the Dagu River of Shandong Peninsula during the dry (May) and wet (September) seasons in 2022 for the determination of total organic carbon (TOC) and nitrogen (TN), stable carbon isotopes (δ13C), biomarkers, and mineralogical parameters. The results showed that the sources of organic matter in the surface suspended particulate matter in the Dagu River in the wet and dry seasons were quite different. The surface suspended particulate matter in the wet season had a negative δ13C (–29.1‰) and a low POC/PN (6.3), and its organic matter mainly came from river phytoplankton; the surface suspended particulate matter in the dry season had a more positive δ13C (–26.8‰) and a higher POC/PN (8.8), and its organic matter were derived from river phytoplankton as well as from C3and C4plants brought in by riverine erosion of the soil, and the source of organic matter in surface sediments were more complicated, in addition to river phytoplankton, the contribution of C3 plants, C4 plants, marine phytoplankton, and sewage source were also mixed. The relative contribution of the terrestrial organic matter in river sediments based on the two-end member model of δ13C decreases from 58% to 0% from upstream to downstream. Principal component analysis showed that the presence of dissolved inorganic nitrogen (DIN) led to phytoplankton blooms in the river corresponding to high levels of POC, chlorophyll-a and short-chain alkanes. The sediments in the estuarine section could absorb more organic matters due to fine grain size and large specific surface area, thus resulting higher TOC content than that in the riverine section. Comparison of the TOC loading in riverine and estuarine sediments showed that the organic matters underwent resuspension during transportation, and the longer oxygen exposure time resulted in the microbial decomposition of about 85% of the terrestrial organic matter into CO2. The results of this study provide data support and references for understanding the source and conservation characteristics of organic matters in small and medium-sized rivers.
黄铁汉, 刘珂, 李莉, 肖晓彤. 大沽河流域有机质来源、保存及影响因素分析[J]. 中国环境科学, 2024, 44(7): 3919-3930.
HUANG Tie-han, LIU Ke, LI Li, XIAO Xiao-tong. Sources, preservation, and influencing factors of organic carbon from the Dagu River Basin. CHINA ENVIRONMENTAL SCIENCECE, 2024, 44(7): 3919-3930.
[1] Hedges J I, Keil R G, Benner R. What happens to terrestrial organic matter in the ocean? [J]. Organic Geochemistry, 1997,27(5):195-212. [2] Galy V, Peucker-Ehrenbrink B, Eglinton T. Global carbon export from the terrestrial biosphere controlled by erosion [J]. Nature, 2015,521(7551):204-207. [3] Schlünz B, Schneider R R. Transport of terrestrial organic carbon to the oceans by rivers: Re-estimating flux- and burial rates [J]. International Journal of Earth Sciences, 2000,88(4):599-606. [4] Yang M, Liu Z, Sun H, et al. Organic carbon source tracing and DIC fertilization effect in the Pearl River: Insights from lipid biomarker and geochemical analysis [J]. Applied Geochemistry, 2016,73:132-141. [5] Han L, Wang Y, Xiao W, et al. Seasonal changes of organic carbon mixing, degradation and deposition in Yangtze River dominated margin related to intrinsic molecular and external environmental factors [J]. Journal of Geophysical Research: Biogeosciences, 2021, 126(12):e2021JG006637. [6] Zhang W, Jin H, Yao X, et al. Grain size composition and transport of sedimentary organic carbon in the Changjiang River (Yangtze River) Estuary and Hangzhou Bay and their adjacent waters [J]. Acta Oceanologica Sinica, 2015,34(10):46-56. [7] Ge T, Xue Y, Jiang X, et al. Sources and radiocarbon ages of organic carbon in different grain size fractions of Yellow River-transported particles and coastal sediments [J]. Chemical Geology, 2020,534:119452. [8] Li Y, Fu C, Zeng L, et al. Changes in organic carbon fractions and sources in deltaic topsoil and subsoil layers: Autochthonous and allochthonous inputs [J]. European Journal of Soil Science, 2021, 72(5):2276-2291. [9] Farnsworth K L, Milliman J D. Effects of climatic and anthropogenic change on small mountainous rivers: The Salinas River example [J]. Global and Planetary Change, 2003,39(1):53-64. [10] Kao S J, Milliman J D. Water and sediment discharge from small mountainous rivers, Taiwan: The roles of lithology, episodic events, and human activities [J]. The Journal of Geology, 2008,116(5):431-448. [11] Liu J T, Hung J J, Huang Y W. Partition of suspended and riverbed sediments related to the salt-wedge in the lower reaches of a small mountainous river [J]. Marine Geology, 2009,264(3):152-164. [12] Milliman J D, Farnsworth K L. River discharge to the coastal ocean: A global synthesis [M]. Cambridge: Cambridge University Press, 2011. [13] Blair N E, Aller R C. The fate of terrestrial organic carbon in the marine environment [J]. Annual Review of Marine Science, 2012, 4(1):401-423. [14] Bianchi T S. Estuarine science and biogeochemical cycles [M]. Oxford University Press, 2006:0. [15] O’Reilly S S, Szpak M T, Flanagan P V, et al. Biomarkers reveal the effects of hydrography on the sources and fate of marine and terrestrial organic matter in the western Irish Sea [J]. Estuarine, Coastal and Shelf Science, 2014,136:157-171. [16] Raymond P A, Bauer J E. Riverine export of aged terrestrial organic matter to the North Atlantic Ocean [J]. Nature, 2001,409(6819):497-500. [17] Ruttenberg K C, Goñi M A. Phosphorus distribution, C:N:P ratios, and δ13Coc in arctic, temperate, and tropical coastal sediments: Tools for characterizing bulk sedimentary organic matter [J]. Marine Geology, 1997,139(1):123-145. [18] 张连凯,覃小群,杨慧,等.珠江流域河流碳输出通量及变化特征[J]. 环境科学, 2013,34(8):3025-3034. Zhang L K, Qin X Q, Yang H, et al. Transported fluxes of the riverine carbon and seasonal variation in Pearl River basin [J]. Environmental Science, 2013,34(8):3025-3034. [19] 孟盼盼.大沽河流域地下水污染现状及成因分析[J]. 绿色科技, 2020,(20):85-87. Meng P P. Analysis of groundwater pollution status and causes in Dagu River basin [J]. Journal of Green Science and Technology, 2020,(20):85-87. [20] 马晓波.大沽河河口区氮磷营养盐输移转化行为特性研究[D]. 青岛:中国海洋大学, 2015. Ma X B. Research on nitrogen and phosphate transport and transformation at Dagu Estuary [D]. Qingdao: Ocean University of China, 2015. [21] 张禹洋,聂世豪,蔡国强,等.植被缓冲带对地表径流阻控效果调查及模拟[J]. 水土保持研究, 2022,29(2):36-42. Zhang Y Y, Nie S H, Cai G Q, et al. Investigation and simulation on the effect of vegetation filter strip on surface runoff [J]. Research on Soil and Water Conservation, 2022,29(2):36-42. [22] 张艳艳,孔范龙,郗敏,等.青岛市湿地保护红线划定研究[J]. 湿地科学, 2016,14(1):129-136. Zhang Y Y, Kong F L, Xi M, et al. Delimitation of red line of wetland conservation in Qingdao city [J]. Wetland Science, 2016,14(1):129-136. [23] 丁冰岚,姜德娟,李新举,等.山东大沽河溶解性碳的时空分布及影响因素[J]. 农业环境科学学报, 2022,41(3):670-680. Ding B L, Jiang D J, Li X J, et al. Tempo-spatial distribution and its influencing factors of dissolved carbon in the Dagu River, Shandong Province [J]. Journal of Agro-Environment Science, 2022,41(3):670-680. [24] 董妍汝.大沽河下游主要支流沉积物DOM的来源、结构特征及生态指示[D]. 青岛大学, 2020. Dong Y R. Source, structural characteristics and ecological indication of sediment DOM in the primary tributaries of Dagu River downstream [D]. Qingdao: Qingdao University, 2020. [25] Liu K, Xiao X, Zhang D, et al. Quantitative estimates of organic carbon contributions to the river-estuary-marine system in the Jiaozhou Bay, China [J]. Ecological Indicators, 2021,129:107929. [26] 盛茂刚,崔峻岭,时青,等.青岛市环胶州湾各河流输沙特征分析[J]. 水文, 2014,34(3):92-96. Sheng M G, Cui J L, Shi Q, et al. Analysis of sediment discharge characteristics of rivers in Jiaozhou Bay, Qingdao city [J]. Journal of China Hydrology, 2014,34(3):92-96. [27] Yi W, Jianying H, Lihui A, et al. Determination of trophic relationships within a Bohai Bay food web using stable δ15N and δ13C analysis [J]. Chinese Science Bulletin, 2005,50(10):1021-1025. [28] Deines P. Chapter 9-THE Isotopic composition of reduced organic carbon [C]. 1980:329-406. [29] Hedges J I, Keil R G, Benner R. What happens to terrestrial organic matter in the ocean? [J]. Organic Geochemistry, 1997,27(5):195-212. [30] Li X, Zhang Z, Wade T L, et al. Sources and compositional distribution of organic carbon in surface sediments from the lower Pearl River to the coastal South China Sea [J]. Journal of Geophysical Research: Biogeosciences, 2017,122(8):2104-2117. [31] 王猛,王玉珏,刘栋,等.胶州湾水体和表层沉积物营养环境现状及影响因素[J]. 海洋学报, 2022,44(10):49-62. Wang M, Wang Y J, Liu D, et al. Nutritional environment and influencing factors of seawater and surface sediments in the Jiaozhou Bay [J]. Haiyang Xuebao, 2022,44(10):49-62. [32] 杨慧,李国庆,周越,等.近30a来胶州湾潮间带动态变化分析[J]. 应用海洋学学报, 2018,37(2):294-300. Yang H, Li G Q, Zhou Y, et al. Tidal zone dynamics in Jiaozhou Bay in recent 30 years [J]. Journal of Applied Oceanography, 2018,37(2): 294-300. [33] Rimmelin P, Dumon J C, Maneux E, et al. Study of Annual and Seasonal Dissolved Inorganic Nitrogen Inputs into the Arcachon Lagoon, Atlantic Coast (France) [J]. Estuarine, Coastal and Shelf Science, 1998,47(5):649-659. [34] Zhang F, Fu H, Lou H, et al. Assessment of eutrophication from Xiaoqing River estuary to Laizhou Bay: Further warning of ecosystem degradation in typically polluted estuary [J]. Marine Pollution Bulletin, 2023,193:115209. [35] Wang Z, Liu K. Nutrients transport behavior in inlet river in the Yellow River Delta in winter [J]. Marine Pollution Bulletin, 2023, 197:115815. [36] 夏云,张波涛,姜德娟.黄海溶解无机氮及颗粒有机氮收支与转化模型[J]. 农业环境科学学报, 2020,39(1):182-190. Xia Y, Zhang B T, Jiang D J. Budgets and transformation of dissolved inorganic and particulate organic nitrogen in the Yellow Sea: A model study [J]. China Environmental Science, 2020,39(1):182-190. [37] 青岛母亲河浑身是伤河道上肆意挖沙千疮百孔|半岛网[EB/OL]. [2023-07-13]. [38] Aller R C. Mobile deltaic and continental shelf muds as suboxic, fluidized bed reactors [J]. Marine Chemistry, 1998,61(3):143-155. [39] 潘慧慧,姚鹏,赵彬,等.基于水淘选分级的长江口最大浑浊带附近颗粒有机碳的来源、分布和保存[J]. 海洋学报, 2015,37(4):1-15. Pan H H, Yao P, Zhao B, et al. Sources,distribution and preservation of size-fractionated particulate organic carbon in the turbidity maximum zone of the Changjiang Estuary based on water elutriation [J]. Acta Oceanologica Sinica, 2015,37(4):1-15. [40] 张学雷,朱明远,陈尚,等.桑沟湾和胶州湾沉积物耗氧率研究[J]. 海洋科学进展, 2006,(1):91-96. Zhang X L, Zhu M Y, Chen S, et al. Study on sediment oxygen consumption rate in the Sanggou Bay and Jiaozhou Bay [J]. Advances in Marine Science, 2006,(1):91-96. [41] Aller R C, Blair N E. Carbon remineralization in the Amazon–Guianas tropical mobile mudbelt: A sedimentary incinerator [J]. Continental Shelf Research, 2006,26(17):2241-2259. [42] Keil R G, Mayer L M, Quay P D, et al. Loss of organic matter from riverine particles in deltas [J]. Geochimica et Cosmochimica Acta, 1997,61(7):1507-1511.