Sources and transport of organic carbon from the Dongjiang River to the Humen outlet of the Pearl River, southern China

doi:10.1007/s11442-014-1078-2

Abstract

Abstract:

Transport of organic carbon via rivers to estuary is a significant geochemical process in the global carbon cycle. This paper presents bulk total organic carbon (TOC) from the Dongjiang catchment to the adjacent Humen outlet, and discusses the applicability of δ¹³C and ratio of carbon to nitrogen (C/N) as indicators for sources of organic matter in the surface sediments. Survey results showed that organic carbon concentration in summer were higher than in the winter. An elevated trend of TOC occurred along the river to the Humen outlet in both surveys, and the highest mean values of dissolved and particular organic carbon (DOC~279 μmol L^-1 and POC~163 μmol L^-1) were observed in the urban deltaic region in summer flood flow. Winter samples had a wide range of δ¹³C and C/N (δ¹³C -24.6‰ to -30.0‰, C/N 4-13), and summer ones varied slightly (δ¹³C -24.2‰ to -27.6‰, C/N 6-18). As results suggest that POC in the three zones of upstream-delta-outlet dominantly came from riverbank soil, phytoplankton and agricultural C3 plants in winter, whereas main sources were from the riverbank and mangrove soil in summer. Moreover, anthropogenic sewage inputs had 11% and 7% contribution to POC in the deltaic and outlet. Transport accompanied with seasonal freshwater variation, phytoplankton production and degradation, and removal behavior caused variation of organic carbon concentration. The results also discovered that TOC export bulk in Dongjiang was approximately one quarter of Humen flux in the dry flow, and anthropogenic activity significantly impacted the river export contribution.

Key words: Dongjiang River, Humen outlet, total organic carbon, flux, δ¹³C, C/N

FU Yingchun, TANG Congguo, LI Jun, ZHAO Yaolong, ZHONG Wei, ZENG Xiantie. Sources and transport of organic carbon from the Dongjiang River to the Humen outlet of the Pearl River, southern China[J]., 2014, 24(1): 143-158.

References

Abril G M, Nogueira H, Etcheber G et al., 2002. Behaviour of organic carbon in nine contrasting European estuaries. Estuarine, Coastal and Shelf Science, 54: 241-262.
Bai J H, Xiao R, Cui B S et al., 2011. Assessment of heavy metal pollution in wetland soils from the young and old reclaimed regions in the Pearl River Estuary, South China. Environmental Pollution, 159: 817-824.
Balakrishna K, Probst J L, 2005. Organic carbon transport and C/N ratio variations in a large tropical river: Godavari as a case study, India. Biogeochemistry, 73: 457-473.
Barros G V, Martinelli L A, Oliveira Novas T M et al., 2010. Stable isotopes of bulk organic matter to trace carbon and nitrogen dynamics in an estuarine ecosystem in Babitonga Bay (Santa Catarina, Brazil). Science of the Total Environment, 408: 2226-2232.
Bouillon S, Connolly R M, 2009. Carbon exchange among tropical coastal ecosystems. In: Nagelkerken I. Ecological Connectivity among Tropical Coastal Ecosystems. Springer, 45-70.
Cai D L, 1998. Geochemical studies on organic carbon isotope of the Huanghe River (Yellow River) Estuary. Science in China (Series B), 37(8): 1001-1015. (in Chinese)
Cai Y Y, Han W Y, 1990. Research of organic carbon of the Pearl River Estuary. Marine Environmental Science, 9(2): 8-12.
Callahan J, He M, Chen R F et al., 2004. Distribution of dissolved organic matter in the Pearl River Estuary, China. Marine Chemistry, 89: 211-224.
Chen Z Q, Li Y, Pan J M, 2004. Distributions of colored dissolved organic matter and dissolved organic carbon in the Pearl River Estuary, China. Continental Shelf Research, 24: 1845-1856.
Cifuentes L A, Coffin R B, Solorzano L et al., 1996. Isotopic and elemental variations of carbon and nitrogen in a mangrove estuary. Estuarine, Coastal and Shelf Science, 43: 781-800.
Cole J J, Prairie Y T, Caraco N F et al., 2007. Plumbing the global carbon cycle: Integrating inland waters into the terrestrial carbon budget. Ecosystems, 10: 171-184.
Dittmar T, Lara R J, 2001. Driving forces behind nutrient and organic matter dynamics in a mangrove tidal creek in North Brazil. Estuarine, Coastal and Shelf Science, 52: 249-259
Fogel M L, Cifuentes L A, 1993. Isotope fractionation during primary production. In: Engel M H (ed.). Organic Geochemistry: Principles and Applications. New York: Plenum Press, 73-98.
Fry B, Sherr E B, 1984. δ¹³C measurements as indicators of carbon flow in marine and freshwater ecosystems. Marine Science, 27: 13-47.
Gao J H, Wang Y P, Pan S M et al., 2008. Spatial distributions of organic carbon and nitrogen and their isotopic compositions in sediments of the Changjiang Estuary and its adjacent sea area. Journal of Geographical Sciences, 18(1): 46-58.
Gao Q Z, Tao Z, Shen C D et al., 2002. Riverine organic carbon in the Xijiang River (South China): Seasonal variation in content and flux budget. Environmental Geology, 41: 826-832.
Gao Q Z, Tao Z, Yao G et al., 2007. Elemental and isotopic signatures of particulate organic carbon in the Zengjiang River, southern China. Hydrological Process, 21: 1318-1327.
Goni M A, Thomas K A, 2000. Sources and transformations of organic matter in surface soils and sediments from a tidal estuary, North Inlet, South Carolina, USA. Estuaries, 23: 548-564.
Gonneea M E, Paytan A, Herrera-Silveira, 2004. Tracing organic matter sources and carbon burial in mangrove sediments over the past 160 years. Estuarine, Coastal and Shelf Science, 61: 211-227
Griffith D R, Barnes R T, Raymond P A et al., 2009. Inputs of fossil carbon from wastewater treatment plants to U.S. rivers and oceans. Environmental Science & Technology, 43(15): 5647-5651.
He B Y, Dai M H, Huang W et al., 2010. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions. Biogeosciences, 7: 3343-3362.
He B Y, Dai M H, Zhai W et al., 2000. Distribution, degradation and dynamics of dissolved organic carbon and its major compound classes in the Pearl River estuary, China. Marine Chemistry: 119: 52-64.
Hedges J I, 1992. Global biogeochemical cycles: Progress and problems. Marine Chemistry, 39: 67-93.
Hedges J I, Keil R G, Benner R, 1997. What happens to terrestrial organic matter in the ocean? Organic Geochemistry, 27(5/6): 195-212.
Hu J F, Peng P A, Jia G D et al., 2006. Distribution and sources of organic carbon, nitrogen and their isotopes in sediments of the subtropical Pearl River estuary and adjacent shelf, southern China. Marine Chemistry, 98: 274-285.
Jia G D, Peng P A, 2003. Temporal and spatial variations in signatures of sedimented organic matter in Lingding Bay (Pearl estuary), southern China. Marine Chemistry, 82: 47-54.
Jia G D, Xu S D, Chen W F et al., 2013. 100-year ecosystem history elucidated from inner shelf sediments off the Pearl River estuary, China. Marine Chemistry, 151: 47-55.
Jiao S L, Tao Z, Gao Q Z et al., 2008. Stable isotopic composition of riverine dissolved inorganic carbon of the Xijiang River Inner Estuary. Journal of Geographical Sciences, 18(3): 363-372.
Kao S J, Liu K K, 1997. Fluxes of dissolved and nonfossil particulate organic carbon from an Oceania small river (Lanyang Hsi) in Taiwan. Biogeochemistry, 39: 255-269.
Li X, 1997. Application of remote sensing for monitoring and analysis of urban expansion: A case study of Dongguan. Geographical Research, 16(4): 56-62.
Liu Kon-Kee, Kao Shuh-Ji, Wen Liang-Saw et al., 2007. Carbon and nitrogen isotopic compositions of particulate organic matter and biogeochemical processes in the eutrophic Danshuei Estuary in northern Taiwan. Science of the Total Environment, 382: 103-120.
Ludwig W, Probst J L, Kempe S, 1996. Predicting the oceanic input of organic carbon by continental erosion. Global Biogeochemical Cycles, 10(1): 3-41.
Meybeck M, 1982. Carbon, nitrogen, and phosphorous transport by world rivers. American Journal of Science, 282(4): 401-450.
Meybeck M, Vörösmarty C, 1999. Global transfer of carbon by rivers. Global Change Newsletter, 37: 18-19.
Meyers P A, 1997. Organic geochemical proxies of paleoceanographic, paleolimnologic, and paleoc-limatic processes. Organic Geochemistry, 27: 213-250
Ni H G, Liu F H, Luo X L et al., 2008. Riverine inputs of total organic carbon and suspended particulate matter from the Pearl River Delta to the coastal ocean off South China. Marine Pollution Bull., 56: 1150-1157.
Ouyang Y, 2003. Simulating dynamic load of naturally occurring TOC from watershed into a river. Water Resource, 37: 823-832.
PRWRC/PRRCC, 1991. The Pearl River Records 1 (Zhujiang Zhi). Guangzhou: Guangdong Science and Technology Press, 271. (in Chinese)
Saliot A, Parrish C C, Sadouni N M et al., 2002. Transport and fate of Danube Delta terrestrial organic matter in the Northwest Black Sea mixing zone. Marine Chemistry, 79: 243-259.
Spitzy A, Ittekkot V, 1991. Dissolved and particulate organic carbon in rivers. In: Mantoura R F C, Martin J M, Wollast R eds. Ocean Margin Processes in Global Change. New York: John Wiley and Sons, 5-17.
Statistical Yearbook of Guangdong (SYG), 2000. Statistical Bureau of Guangdong Province, Beijing: China Statistics Press, 60. (in Chinese)
Statistical Yearbook of Huizhou (STY), 2005. Statistical Department of Huizhou (Guangdong Province). Beijing: China Statistics Press, 370-371. (in Chinese)
Sun H G, Han J, Lu X X et al., 2010. An assessment of the riverine carbon flux of the Xijiang River during the past 50 years. Quaternary International, 226: 38-43.
Tao Z, Gao Q Z, Guo W P et al., 2011. Temporal and spatial variability of dissolved organic carbon concentration in the Xijiang River, South China. Journal of Mountain Science, 8: 694-703, doi: 10.1007/s11629-011-2000-3.
Tucker J, Sheats N, Giblin A E et al., 1999. Using stable isotopes to trace sewage-derived material through Boston Harbor and assachusetts Bay. Marine Environmental Research, 48: 353-375.
Wang G F, Zhou W, Cao W X et al., 2011. Variation of particulate organic carbon and its relationship with bio-optical properties during a phytoplankton bloom in the Pearl River estuary. Marine Pollution Bulletin, 62: 1939-1947.
Wang J T, Yu Z G, Zhang J, 1998. Study on dissolved organic carbon in the estuary of the Yalujiang River. Journal of Ocean University of Qingdao, 28: 471-475. (in Chinese)
Wang X C, Che R F, Gardner G B et al., 2004. Sources and transport of dissolved and particulate organic carbon in the Mississippi River estuary and adjacent coastal waters of the northern Gulf of Mexico. Marine Chemistry, 89: 241-256.
Wei X G, 2003. Study on riverine carbon flux and erosion of Zhujiang (Pearl River) drainage basin. PhD Thesis. Guangzhou: Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. (in Chinese)
Wei X G, Shen C D, Li D Q, 2004. The inventory and fluxes of carbon in soil of Pearl River basin. Ecology and Environment, 13(4): 670-673.
Wei X G, Shen C D, Li N L et al., 2010a. Apparent ages of suspended sediment and soil erosion of the Pearl River (Zhujiang) drainage basin. Chinese Science Bulletin, 55(15): 1547-1553.
Wei X G, Zhou M N, Guo Z X et al., 2010b. Carbon and nitrogen stable isotope composition of soil, vegetation and suspended sediment in Dongjiang river basin. Ecology and Environmental Sciences, 19(5): 1186-1190. (in Chinese)
Wu Y, Zhang J, Liu S M et al., 2007. Sources and distribution of carbon within the Yangtze River System. Estuarine Coastal and Shelf Science, 71: 13-25.
Xiao H Y, Liu C Q, 2010. Identifying organic matter provenance in sediments using isotopic ratios in an urban river. Geochemical Journal, 44: 181-187.
Yin K D, Qian P Y, Wu M C et al., 2001. Shift from P to N limitation of phytoplankton growth across the Peal River estuarine plum during summer. Marine Ecology Progress Series, 221: 17-28.
Yin K D, Zhang J L, Qian P Y et al., 2004. Effect of wind events on phytoplankton blooms in the Pearl River Estuary during summer. Continental Shelf Research, 24: 1909-1923.
Yu F L, Zong Y Q, Jeremy M L, 2010. Bulk organic δ¹³C and C/N as indicators for sediment sources in the Pearl River delta and estuary, Southern China. Estuarine, Coastal and Shelf Science, 87: 618-630.
Zhang J, Yu Z G, Wang J T et al., 1999. The subtropical Zhujiang (Pearl River) estuary: Nutrient, trace species and their relationship to photosynthesis. Estuarine, Coastal and Shelf Science, 49: 385-400.
Zhang N X, Song J M, He Z P, 2006. Biogeochemical mechanism of particulate organic carbon (POC) variations in seawater. Acta Ecological Sinica, 26(7): 2328-2329.
Zhang S R, Lu X X, Higgitt D L et al., 2007. Water chemistry of the Zhujiang (Pearl River): Natural processes and anthropogenic influences. Journal of Geophysical Research, 112: 1-17.
Zhang S R, Lu X X, Sun H G et al., 2009. Geochemical characteristics and fluxes of organic carbon in a human-disturbed mountainous river (the Luodingjiang River) of the Zhujiang (Pearl River), China. Science of the Total Environment, 407: 815-825.
Zong Y Q, Yu F L, Huang G Q, 2010. Sedimentary evidence of Late Holocene human activity in the Pearl River Delta, China. Earth Surface Processes and Landforms, 35: 1095.

[1]	LU Yao, GAO Yang, YANG Tiantian. A review of mass flux monitoring and estimation methods for biogeochemical interface processes in watersheds [J]. Journal of Geographical Sciences, 2020, 30(6): 881-907.
[2]	LI Guodong, ZHANG Junhua, MIRZAEI Parham A., DING Shengyan, DING Yapeng, LIU Man. Monitoring thermal field, humidity field and energy balance over heterogeneous surfaces in the typical valley-city [J]. Journal of Geographical Sciences, 2020, 30(12): 2015-2032.
[3]	Gaocong LI, Liang ZHOU, Yali QI, Shu GAO. Threshold sediment flux for the formation of river deltas in Hainan Island, southern China [J]. Journal of Geographical Sciences, 2019, 29(1): 146-160.
[4]	Guirui YU, Wei REN, Zhi CHEN, Leiming ZHANG, Qiufeng WANG, Xuefa WEN, Nianpeng HE, Li ZHANG, Huajun FANG, Xianjin ZHU, Yang GAO, Xiaomin SUN. Construction and progress of Chinese terrestrial ecosystem carbon, nitrogen and water fluxes coordinated observation [J]. Journal of Geographical Sciences, 2016, 26(7): 803-826.
[5]	LIU Yue, SHINTARO Goto, ZHUANG Dafang, KUANG Wenhui. Urban surface heat fluxes infrared remote sensing inversion and their relationship with land use types [J]. Journal of Geographical Sciences, 2012, 22(4): 699-715.
[6]	QI Yuchun, DONG Yunshe, PENG Qin, XIAO Shengsheng, HE Yating, LIU Xinchao, SUN Liangjie, JIA Junqiang, YANG Zhijie. Effects of a conversion from grassland to cropland on the different soil organic carbon fractions in Inner Mongolia, China [J]. Journal of Geographical Sciences, 2012, 22(2): 315-328.
[7]	YANG Libiao, YAN Weijin, MA Pei, WANG Jianing. Seasonal and diurnal variations in N₂O concentrations and fluxes from three eutrophic rivers in Southeast China [J]. Journal of Geographical Sciences, 2011, 21(5): 820-832.
[8]	SHENG Wenping, REN Shujie, YU Guirui, FANG Huajun, JIANG Chunming, ZHANG Mi. Patterns and driving factors of WUE and NUE in natural forest ecosystems along the North-South Transect of Eastern China [J]. Journal of Geographical Sciences, 2011, 21(4): 651-665.
[9]	LI Yuecong, XU Qinghai, ZHANG Liyan, WANG Xueli, CAO Xianyong,YANG Xiaolan. Modern pollen assemblages of the forest communities and their relationships with vegetation and climate in northern China [J]. Journal of Geographical Sciences, 2009, 19(6): 643-659.
[10]	GAO Jianhua, WANG Yaping, PAN Shaoming, ZHANG Rui, LI Jun, BAI Fenglong. Spatial distributions of organic carbon and nitro-gen and their isotopic compositions in sediments of the Changjiang Estuary and its adjacent sea area [J]. Journal of Geographical Sciences, 2008, 18(1): 46-58.
[11]	JIA Liangwen, LUO Zhangren, YANG Qingshu, OU Shuying, LEI Yaping. Impacts of the large amount of sand mining on riverbed morphology and tidal dynamics in lower reaches and delta of the Dongjiang River [J]. Journal of Geographical Sciences, 2007, 17(2): 197-211.
[12]	WATANABE Masataka, WANG Qinxue, HAYASHI Seiji, MURAKAMI ShogoLIU Jiyuan, OUYANG Zhu, LI Yan, LI Yingnian, WANG Kelin. Monitoring and simulation of water, heat, and CO₂ fluxes in terrestrial ecosystems based on the APEIS-FLUX system [J]. Journal of Geographical Sciences, 2005, 15(2): 131-141.
[13]	John F. MCCARTHY. Carbon fluxes in soil: long-term sequestration in deeper soil horizons [J]. Journal of Geographical Sciences, 2005, 15(2): 149-154.
[14]	WEN Xuefa, YU Guirui, SUN Xiaomin, LI Qingkang, REN Chuanyou, HAN Shijie. Net water vapour exchange over a mixed needle and broad-leaved forest in Changbai Mountain during autumn [J]. Journal of Geographical Sciences, 2003, 13(4): 463-468.
[15]	PEI Zhiyong, OUYANG Hua, ZHOU Caiping, XU Xingliang. Fluxes of CO₂, CH₄ and N₂O from alpine grassland in the Tibetan Plateau [J]. Journal of Geographical Sciences, 2003, 13(1): 27-34.