铁山港海草生态区各种形态N的含量变化及其相互关系

根据2008年1月—2008年11月在铁山港海草生态区进行4个季节月综合调查所获取的数据资料,首次对水体中5种形态氮的含量变化特征及其相互关系进行研究。结果表明:不同形态N的含量变化具有海草生态区特点,TN含量明显偏高,DIN含量却显著偏低,依次排列为:TN>DN>DON>PN>DIN;其中TN、PN和DIN均以春夏季明显高于秋冬季出现,ON则呈夏秋季高、冬春季低特征,只有DON表现为夏季高、秋冬季次之、春季最低。相关分析显示:各种形态N之间以TN与PN、DN与DON之间的关系最为密切,多达非常显著(P≤0.01)的正相关水平,但在季节上却以秋季最为突出,所有形态N之间均以非常显著的正相关出现,具有很好的同源性。整个海区不同形态N/P比均较高,年平均值均在24.64～50.68之间,P相对于N呈匮乏状态,与N的补充源较丰富有关,海草枯落物在其中起重大贡献作用。

Content variation of nitrogen and their mutual relation in the sea-grass bed ecosystem of the Tieshan Bay

Based on the data from the comprehensive investigation on sea-grass bed ecosystem in the Tieshan Bay during Jan.2008 to Nov.2008,the content variation of nitrogen and their mutual relation were studied.The results showed that the variation of contents of different states of nitrogen accorded with the characteristics of sea-grass bed ecosystem.The content of TN was apparently high and DIN was apparently low,and the sequence from high to low was TN > DN > DON > PN > DIN.TN,PN and DIN contents were higher in spring and summer than those in autumn and winter,whereas DN content was higher in autumn and winter.DON content was highest in summer,followed by those in autumn and winter, and lowest in spring.Correlation analysis showed that there was significant correlation(p≤0.01) between TN and PN,and between DN and DON.In autumn,all the states of nitrogen showed notable positive correlation to each other,and their homology was good.The N:P ratio in the sea-grass bed area was high,and the annual average of the ratio was at 24.64 to 50.68.Nitrogen source was richer than Phosphorous,which thanks to the major contribution by sea-grass litter.