|
|
|
Seasonal variation of nitrogen and phosphorus
in Xiaojiang River—A tributary of the Three Gorges Reservoir |
| Zhe LI , Jinsong GUO , Man LONG , Fang FANG , Jinping SHENG , Hong ZHOU , |
| Faculty of Urban Construction
& Environmental Engineering, Chongqing University, Chongqing 400045,
China; |
|
|
|
|
Abstract A yearlong monitoring program in the backwater area of Xiaojiang River (XBA) was launched in order to investigate the eutrophication of backwater areas in tributaries of the Yangtze River in the Three Gorges Reservoir (TGR) in China, starting after the impoundment water level of the TGR reached 156 m. From March 2007 to March 2008, the average concentration of total nitrogen (TN) and total phosphorus (TP) were (1553 ± 484) μg·L−1 and (62 ± 31) μg·L−1, respectively. The mean value of chlorophyll was (9.07 ± 0.91) μg·L−1. The trophic level of XBA was meso-eutrophic, while the general nutrient limitation was phosphorus. The results indicated that XBA has a strong ability to purify itself and has non-point source pollution from terrestrial runoff. The variation of TN/TP ratio was caused by a variation in TN rather than in TP when TN/TP<22. N-fixation from cyanobacteria occurred and became an important process in overcoming the nitrogen deficit under a low TN/TP ratio. When TN/TP ≥ 22, the variation of TP affected the TN/TP ratio more significantly than TN. The increase of TP in XBA was caused mainly by particulate phosphorus, which could originate from a non-point source as adsorptive inorganic forms after heavy rainfall and surface runoff. An increase in the river’s flow could also contribute to an unstable environment for the growth of phytoplankton.
|
| Keywords
Three Gorges Reservoir
eutrophication
nitrogen
phosphorus
seasonal variation
chlorophyll
|
|
Issue Date: 05 September 2009
|
|
|
Wang B. Culturaleutrophication in the Changjiang (Yangtze River) plume: History andperspective. Estuarine, Coastal and ShelfScience, 2006, 69(3―4): 471―477
doi: 10.1016/j.ecss.2006.05.010
|
|
Cai Q, Hu Z. Studies on eutrophicationproblem and control strategy in the Three Gorges Reservoir. Acta Hydobiologica Sinica, 2006, 30(1): 7―11 (in Chinese)
|
|
Wu J, Huang J, Han X, Xie Z, Gao X. Three-Gorges Dam: Experiment in habitatfragmentation? Science, 2003, 300: 1239―1240
doi: 10.1126/science.1083312
|
|
Zeng H, Song L, Yu Z, Chen H. Distributionof phytoplankton in the Three-Gorge Reservoir during rainy and dryseasons. Science of the Total Environment, 2006, 367: 999―1009
doi: 10.1016/j.scitotenv.2006.03.001
|
|
Cao M, Cai Q, Liu R, Qu X, Ye L. Comparative research on physicochemical factors betweenXiangxi Bay and the front region of Three Gorges Reservoir. Acta Hydobiologica Sinica, 2006, 30(1): 20―25 (in Chinese)
|
|
Allan J, Castillo M. Stream Ecology: Structureand Function of Running Waters. Netherlands: Springer Press, 2007, 255―265
|
|
CEPA. Monitoringand Analysing Methods for Water and Wastewater. 4th ed. Beijing: China Environmental Science Press, 2002, 243―285 (in Chinese)
|
|
Li Z, Guo J, Fang F, Chen J, Zhang C, Tian G. Studyon spring algal bloom and nutrients characteristics in Xiaojiang RiverBackwater Area, Three Gorge Reservoir.Journal of Lake Science, 2009, 21(1): 86―94 (in Chinese)
|
|
Guildford S, Hecky R. Total nitrogen, total phosphorus,and nutrient limitation in lakes and oceans: Is there a common relationship? Limnology and Oceanography, 2000, 45(6): 1213―1223
|
|
Wetzel R G. Limnology: Lake and River Ecosystems. CA: Academic Press, 2001, 201―300
|
|
Håkanson L, Bryhn A, Hytteborn J. On the issue of limiting nutrient and prediction of cyanobacteriain aquatic systems. Science of the TotalEnvironment, 2007, 379: 89―108
doi: 10.1016/j.scitotenv.2007.03.009
|
|
Zheng B, Cao C, Qin Y, Huang M. Analysis ofnitrogen distribution characters and their sources of the major inputrivers of Three Gorges Reservoir. EnvironmentalScience, 2008, 29(1): 1―6 (in Chinese)
|
|
Havens K, James R, East T, Smith V. N:P Ratios,light limitation, and cyanobacterial dominance in a subtrophical lakeimpacted by non-point source nutrient pollution. Environmental Pollution, 2003, 122: 379―390
doi: 10.1016/S0269-7491(02)00304-4
|
|
Downing J, McCauley E. The nitrogen:phosphorus relationshipin lakes. Limnology and Oceanography, 1992, 37(5): 936―945
|
|
Howarth R, Marino R, Lane J. Nitrogen fixation in freshwater, estuarine, and marineecosystems. 1. Rates and importance. Limnologyand Oceanography, 1988, 33(4, part 2): 668―687
|
|
Xie L, Xie P, Li S, Tang H, Liu H. The low TN:TP ratio, a cause or a resultof Microcystis blooms? Water Research, 2003, 37: 2073―2080
doi: 10.1016/S0043-1354(02)00532-8
|
|
Ha K, Jan M, Joo G. Spatial and temporal dynamics of phytoplankton communitiesalong a regulated river system, the Nakdong River, Korea. Hydrobiologia, 2002, 470: 235―245
doi: 10.1023/A:1015610900467
|
|
Smith V. Thenitrogen and phosphorus dependence of algal biomass in lakes: An empiricaland theoretical analysis. Limnology andOceanography, 1982, 27(6): 1011―1112
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
