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作 者 ：杨明生,熊邦喜,杨学芬,张清顺

期 刊 ：生态学报 2008年 28卷 4期 页码：1508~1513

关键词：南湖；沉积物；水生植物残体；总氮；总磷；分布；

Keywords:Nanhu Lake, sediments, aquatic plant residues, total nitrogen, total phosphorus, distribution,

摘 要 ：对武汉市南湖5个采样点30 cm沉积物柱样中水生植物残体的含量、植物残体的总氮和总磷量进行了研究。结果表明，在南湖中水生植物残体具有较大的沉积量，是一个重要的N、P库；不同采样点之间，水生植物残体的含量有着较大的差异性。在水生植物残体的TN和TP的垂向分布上，0~5cm段TN为20.230 mg•g-1, 25～30 cm段TN为 20.613 mg•g-1,检测TN 与沉积深度的相关系数为0.5851，P＞P 0.05,两者相关不显著；0～5cm 段的TP为2.546 mg•g-1 ，25~30 cm段的TP为 0.634 mg•g-1，上下相差4倍，TP 与沉积深度的相关系数为－0.9507（P＜P 0.01），说明两者呈紧密负相关，即沉积年代越早，TP值越低；沉积年代越晚，TP值越高，这与南湖的富营养化过程是一致的。研究表明，湖泊沉积物中的水生植物残体可作为湖泊富营养化过程的一种新的证据材料，其TP值可以作为一个环境变化的指标，对研究长江中下游浅水湖泊的富营养化过程具有参考意义。

Abstract:Nanhu Lake (30°29′N，114°21′E) is a shallow lake along the middle reaches of Yangtze River with a main surface area of 400 hm2, situated in Wuhan City, Hubei Province of China. There were large amounts of hydrophyte including submerged hydrophyte in Nanhu Lake in early 1980s. However, it has been developed into a eutrophic lake because of the inputs of massive nutrients and the water quality has been deteriorated, and no submerging plant could be discovered now. The distributions of the total nitrogen (TN) and total phosphorus (TP) in aquatic plant residues within 30 cm sediment cores of 5 sampling sites were studied during May, 2006. The results show that plant residue is an important N and P pool, substantial differences of aquatic plant residues content could be found among different sampling sites, and the largest amounts of aquatic plant residues in 5 sites are different according to its depth——site Ⅰ is in the depth of 11-15 cm; site Ⅱ is in the depth of 25-30 cm, and site Ⅲ is in the depth of 16-20 cm. However, site Ⅳ and site Ⅴ gradually increase from surface to bottom within 30cm sediments column in Nanhu Lake. The research on the aquatic plant residues shows that spatial distribution of aquatic plant in Nanhu Lake was uneven during the past decades .TN in the section of 0 cm to 5 cm is 20.230 mg•g-1, and 20.613 mg•g-1 in the section of 25 cm to 30 cm, respectively. The correlation coefficient between TN content and depth is 0.5851 (P > P 0.05), indicating no significant correlation between them. While TP in the two sections above are 2.546 mg•g-1 and 0.634 mg•g-1, respectively, four times discrepancy, and the correlation coefficient is -0.9507(P＜P 0.01), with a close negative correlation between TP content and the depth. Which means that the earlier the sediments were, the lower the TP content was,with vice versa. This is consistent with the eutrophication process of the Nanhu Lake. The study shows that aquatic plant residues in the sediments could be used as a new evidence during the eutrophic process, and the TP value could regarding as index of environment change, which provides a significant reference to the investigation of the eutrophic process in shallow lakes from the middle and lower reaches of Yangtze River region in China.

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