Pedosphere 14(4): 483--490, 2004
ISSN 1002-0160/CN 32-1315/P
©2004 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Lake sediments from Dianchi Lake: A phosphorus sink or source? |
GAO Li1,2 , YANG Hao1, ZHOU Jian-Min1, LÜ Jun-Jie1 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China). E-mail: ligoo117@126.com
2 Ocean School, Yantai Univercity, Yantai 204005 (China) |
| ABSTRACT |
| Dianchi Lake is a highly eutrophic lake in southwestern China where phosphorus (P) is the limiting element for eutrophication and where lake sediments play an important role in the P cycle. One hundred and eighteen sites were sampled throughout Dianchi Lake in 2002 to investigate the P loading of the lake sediments, while fresh surface sediments were studied in the laboratory to clarify its role for phosphorus. The results showed that concentrations of total phosphorus (TP) in sediments were very high, with a maximum value of 6.66 g kg-1, and decreased with sediment depth. P adsorption on surface sediments was rapid with adsorption amounts higher in acidic than in alkaline conditions. The release experiments showed that P release increased as pH rose from 7.0 to 10.5. Additionally, compared with aerobic conditions, P release was much higher under anaerobic: conditions, especially with low P content in the lake water. At present, the sediments in Dianchi Lake still function as a sink for phosphorus at high P levels in lake water. However, if the external P load was reduced and P content in lake water became low, the sediment would have a large potential for P release under anaerobic conditions. |
| Key Words: adsorption, Dianchi Lake, phosphorus, release, sediment |
| Citation: Gao, L., Yang, H., Zhou, J. M. and LÜ Jun-Jie. 2004. Lake sediments from Dianchi Lake: A phosphorus sink or source?. Pedosphere. 14(4): 483-490. |
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