闽江河口湿地短叶茳芏氮、磷含量与积累量季节变化

Seasonal variation of nitrogen and phosphorus concentration and accumulation of Cyperus malaccensis in Minjiang River estuary

对闽江河口湿地优势植物短叶茳芏(Cyperus malaccensis)N、P养分含量与积累量进行了1年的监测。结果表明:地上部分N、P浓度的器官分配模式为花>叶>茎,绿色部分大于立枯部分,冬春季节浓度>夏秋季节;N、P积累量的器官分配为茎>叶>花,地下部分N、P浓度和积累量空间变化趋势一致,即0～15cm>15～30cm>30～60cm;地上N平均浓度、N、P积累量在各个季节始终高于地下部分,但地上与地下P平均浓度的高低呈波动变化,N积累总量在秋季达到最大值(42.9g.m-2),P积累总量在夏季达到最大值(7.3g.m-2);P浓度和积累总量极显著地低于N(P<0.01)。从N/P比值看,N为限制短叶茳芏初级生产力的一个重要营养因子。

A one-year investigation on the N and P concentration and accumulation of Cyperus malaccensis in the wetlands of Minjiang River estuary showed that the N and P concentration of C. malaccensis aboveground parts was in the order of flower 〉 leave 〉 stem, being higher in living plants than in dead standings, and in spring and winter than in autumn and summer; while the N and P accumulation was in the order of stem 〉 leave 〉 flower. The N and P concentration and accumulation of C. malaccensis below ground parts were 0-15 cm 〉 15-30 cm 〉30-60 cm. The average N concentration and the N and P accumulation of aboveground parts were higher than those of belowground parts, while the average P concentration fluctuated throughout the year. The N accumulation reached the peak （42. 9 g · m^-2） in autumn, while P accumulation had its peak （7.3 g · m^-2） in summer. The P concentration and accumulation were significantly lower than N （ P 〈 0.01 ）. From the viewpoint of N/P ratio, N was a key element limiting the primary productivity of C. malaccensis.