Different hydrodynamic conditions on the deposition of organic carbon in sediment of two reservoirs
- 494 Downloads
In regulated freshwater ecosystems, the deposition process of organic carbon (OC) in sediment could be affected by all the changes of physical, chemical, and biological factors. To assess different hydrodynamic conditions on the deposition of OC in sediment, the combination of elemental and stable isotope analyses was carried out in two reservoirs: the Huairou Reservoir (HR), which undergoes seasonal water level fluctuation (WLF) like natural lakes, and the Shisanling Reservoir (SR), which undergoes daily WLF for the operation of pumped storage power station. In general, OC concentration and its variation were comparable in the two reservoirs, whereas the OC distribution showed completely different features. The OC burial rate in SR was nearly two times more than in the HR, which reflect the impact of WLFs on the erosion of soil. For the relative contribution of phytoplankton-derived OC (P-OC), macrophyte-derived OC (M-OC), and terrestrial OC (T-OC) in sediment, the T-OC and M-OC in the SR were both higher than those of the HR, whereas the P-OC was markedly lower. Furthermore, the classification of nearshore and offshore sediments suggested that hydrodynamic conditions affected the T-OC import by physical processes and the in situ contributions of P-OC and M-OC with a spatial difference.
KeywordsHydrodynamic condition Mixing model Sedimentary organic carbon Stable isotope Water level fluctuation
This work was supported by the State key Laboratory of Hydroscience and Engineering under Grant No. 2012-ky-1. Laboratory measurements for the elemental and stable isotope analyses were carried out in the School of Environment, Tsinghua University. The authors are very grateful to the authorities of Huairou Reservoir and Shisanling Reservoir for providing data, as well as those who helped with the numerous assistant projects during the sampling campaigns.
- Chen, Y., 2008. Studies on hydrophytes diversity of wetland in Beijing. Dissertation, Beijing Forestry University. (in Chinese).Google Scholar
- Cole, J. J., Y. T. Prairie, N. F. Caraco, W. H. McDowell, L. J. Tranvik, R. G. Striegl, C. M. Duarte, P. Kortelainen, J. A. Downing, J. J. Middelburg & J. Melack, 2007. Plumbing the global carbon cycle: Integrating inland waters into the terrestrial carbon budget. Ecosystems 10: 171–184.CrossRefGoogle Scholar
- Downing, J. A., J. J. Cole, J. J. Middelburg, R. G. Striegl, C. M. Duarte, P. Kortelainen, Y. T. Prairie & K. A. Laube, 2008. Sediment organic carbon burial in agriculturally eutrophic impoundments over the last century. Global Biogeochemical Cycles 22: GB1018. doi: 10.1029/2006GB002854.CrossRefGoogle Scholar
- IPCC, 2007. Climate change 2007: the physical science basis. Contribution of Working of Shop Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press.Google Scholar
- Lu, F. Y., Z. Q. Liu & H. B. Ji, 2012. Carbon and nitrogen isotopes analysis and sources of organic matter in the upper reaches of the Chaobai River near Beijing, China. Science China: Earth Sciences 12: 1912–1922. (in Chinese).Google Scholar
- Tenzer, G. E., P. A. Meyers & P. Knoop, 1997. Sources and distribution of organic and carbonate carbon in surface sediments of Pyramid Lake, Nevada. Journal of Sedimentary Research 67: 884–890.Google Scholar
- Tranvik, L. J., J. A. Downing, J. B. Cotner, S. A. Loiselle, R. G. Striegl, T. J. Ballatore, P. Dillon, K. Finlay, K. Fortino, L. B. Knoll, P. L. Kortelainen, T. Kutser, S. Larsen, I. Laurion, D. M. Leech, S. L. McCallister, D. M. McKnight, J. M. Melack, E. Overholt, J. A. Porter, Y. Prairie, W. H. Renwick, F. Roland, B. S. Sherman, D. W. Schindler, S. Sobek, A. Tremblay, M. J. Vanni, A. M. Verschoor, E. von Wachenfeldt & G. A. Weyhenmeyer, 2009. Lakes and reservoirs as regulators of carbon cycling and climate. Limnology and Oceanography 54: 2298–2314.CrossRefGoogle Scholar
- Xing, G. H., 2011. Research on Huairou Reservoir watershed runoff and future water resources management. China Flood & Drought Management 21(S1): 40–42. (in Chinese).Google Scholar
- Zhang, N., X. J. Chen, G. S. Du & Z. F. Huang, 2012. Planktonic algae and trophic state in Huairou Reservoir in Beijing City. Water Resources Protection. 28: 55–58. (in Chinese).Google Scholar