macrophyte (Potamogeton pectinatus) growing zone, sediment characteristics of Lake Wuliangsuhai from different sampling sites began to change abruptly at 32.5-cm depth just when TSL was formed. Ratio of total nitrogen to total phosphorus (N/P) and organic matter that is associated with eutrophic species, such as Potamogeton pectinatus, decreased with depth after the TSL was formed. Dry matter and metals also began to increase with depth above the TSL, indicating a transformation of external source. Data from this study supported such conclusions that it was possible to discriminate trophic state change of the lake by using sediment characteristics, and that anthropogenic pollutant loading was the key factor leading to eutrophication of Lake Wuliangsuhai. Coastal salt marshes contain rich ecosystems and are habitats for many birds and unique halophyte flora; they have high conservation and resource values, sustaining the productivity of estuarine and tidal flat ecosystems and representing important nutrient and contaminant sinks. As one of the most typical areas of coastal salt marsh evolution, the ecological environment is degrading in response to human activities and environmental contamination of the coastal wetlands. In order to understand the environmental quality of the Quanzhou Bay, six short cores were drilled along the coastal salt marshes, including mangrove marsh, Spartina altemiflora marsh and bare flat, these sediment cores were cut at intervals of 5 cm in-situ. At the laboratory, the sediment samples were mixed with HC1 to a concentration of 5% and put aside overnight, and washed with distilled water till pH=7, dried at 60~ and ground as fine power. 36 samples were analyzed for the total organic carbon and total nitrogen using ELEMENTAR. The analysis results show that the average contents of TOC in Spartina altemiflora marsh are (1.05177 much higher than those of mangrove marsh and bare flat, which are (0.84 and (0.91 respectively; the average contents of TN in Spartina altemiflora marsh are (0.16177 higher than those of mangrove marsh and bare flat, which are all (0.14 In the vertical direction, TOC and TN in different salt marshes all tend to decrease downwards. The contents of TOC and TN are higher in Shuitou where heavy contamination is reported than in the Luoyangjiang estuarine. The contaminants in fresh water can be hold back by Spartina altemiflora markedly when the dam is opened to drainage the contaminated water. Coastal salt marshes are among the most productive ecosystems in the world, where there is adequate protection from destructive waves and storms. The important physical and chemical variables that determine the structure and function of the salt marsh include hydrodynamic and nutrient limitation, particularly by nitrogen and sulfur. Sulfur is an interesting marsh soil chemical because of its toxicity, acid-forming properties, and ability to store energy from organic forms. In order to understand the sulfur variability of coastal marshes in the QuanThou Bay, six shorts of cores were collected in different marshes, including mangrove marsh, Spartina altemiflora marsh and bare flat; these sediment cores were cut at intervals of 5 cm in-situ. In the laboratory, the sediments were dried at 60~ and ground as fine power, and 36 samples were analyzed for sulfur by ELEMENTAR. The analysis results show that the average content of S in Spartina altemiflora marsh at Shuitou is (0.28+0.07) %, higher than that of the bare flat, which is (0.21 At Luoyangjiang estuarine, the average content of S in Spartina altemiflora marsh is (0.24 much higher than that of mangrove marsh and bare flat, which are (0.13 and (0.11 respectively. In the vertical direction, S in different salt marshes shows a tendency of decreasing downwards. The contents of S are higher in Shuitou where contamination is heavier than in the Luoyangjiang estuarine.
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