title: [Temporal and Spatial Distribution of Nutrients in Daning River Sediments and Their Correlations with Chlorophyll in the Three Gorges Reservoir Area].
abstract: In order to understand the temporal and spatial distribution of nutrients in Daning river sediments and to investigate the relationship between nutrients and algal cells, samples were selected from 4 typical sampling sites, i. e. Caizi Dam, Baishui River, Shuanglong and Dachang. Vertical gravity mud samplers were used to collect the sediments from different layers within 20 cm in increment of 2 cm. Vertical distributions of TN, NH4(+)-N, NO3(-) -N, NO2(-) -N, TP, inorganic P and organic P in sediments of different sampling sites were investigated. And so was the vertical distribution of chlorophyll. Moreover, the correlation between chlorophyll and the nutrients was analyzed. Results showed that the contents of TN were the highest at the depth of 0.0-2.0 cm in the Caizi Dam sediments, and at the depth of 2.0-4.0 cm in the Baishui River sediments. The highest NH4(+) -N content occurred at 2.0-4.0 cm in the Caizi Dam sediments and at 4.0-6.0 cm in the Baishui River in January and February. As to NO3(-) -N and NO2(-) -N contents, they were the highest at 2.0-4.0 cm in Caizi Dam sediments except March. For NH4(+) -N, NO3(-) -N and NO2(-) -N, there was no significant difference under 4.0 cm sediments at the same sampling site. The distribution of TP was increasing from 0.0 to 6.0 cm in Baizi River sediments. But in Caizi Dam sediments TP and inorganic P contents in 0.0-2.0 cm were higher than those of others layers; TP and inorganic P in all different layers of Caizi Dam sediments were greater than those of corresponding layers in other sampling sites' sediments. The contents of organic P at Caizi Dam and Dachang were higher than those of Baishui River and Shuanglong, while the difference of organic P contents was not significant in different sediments layers at the same sampling site. The chlorophyll a contents in Dachang were the highest at every layer comparing to the corresponding layers of others, followed by Baishui River, Caizi Dam, and Shuanglong. Only one significantly positive correlation was observed between the content of inorganic P and chlorophyll a in Dachang site in January, with the correlation coefficient was 0.87. The correlation results implied that nutrients in sediments were not the main factors affecting the distribution of algal cells.
authors.forename: Yong-sheng
authors.initials: YS
authors.lastname: Zhang
authors.forename: Hai-ying
authors.initials: HY
authors.lastname: Li
authors.forename: Jia-ying
authors.initials: JY
authors.lastname: Ren
authors.forename: Jia
authors.initials: J
authors.lastname: Lu
mesh_terms: D002681:China; D002734:Chlorophyll / Q000032:analysis*; D000077194:Chlorophyll A; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D058086:Microalgae / Q000254:growth & development; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D045483:Rivers / Q000737:chemistry*; D062211:Spatio-Temporal Analysis
chemical_list: D002734:Chlorophyll; D010758:Phosphorus; D009584:Nitrogen; D000077194:Chlorophyll A