闽江河口湿地植物氮磷吸收效率的季节变化

Seasonal dynamics of nitrogen-and phosphorus absorption efficiency of wetland plants in Minjiang River estuary

以闽江河口湿地土著种芦苇与入侵种互花米草为研究对象,测定了二者地上生物量和氮、磷吸收效率.结果表明:芦苇和互花米草地上生物量的季节变化呈典型的单峰值曲线,芦苇夏季地上生物量最大,达到2195.33g·m-2,互花米草则秋季最大,达到3670.02g·m-2;不同季节芦苇和互花米草氮、磷吸收效率均呈单峰值曲线,芦苇氮、磷吸收效率分别在夏季和秋季达到最高(21.06和1.12g·m-2),互花米草均在秋季达到峰值(26.76和3.23g·m-2);芦苇和互花米草的氮吸收效率极显著大于磷(P<0.01),且互花米草的氮、磷吸收效率显著大于芦苇(P<0.05);植物N/P、C/N和C/P对植物氮、磷吸收效率有一定指示意义.

Taking the native Phragmites australis and invasive Spartina alterniflora in Minjiang River estuary as test objectives, this paper studied the seasonal dynamics of their biomass and nitrogen-and phosphorus absorption efficiency. A typical single-peak curve was presented for the seasonal dynamics of aboveground biomass and nitrogen- and phosphorus absorption efficiency of the two species. P. australis had the maximum aboveground biomass （2195.33 g· m^-2） in summer, while S. alterniflora had it （3670. 02 g· m^-2） in autumn. The total nitrogen （TN） and total phosphorus （TP） contents ofP. australis reached the peak （21.06 g· m^-2 of TN and 1.12 g· m^-2 of TP） in summer and in autumn, respectively, while those of S. alterniflora all reached the peak （26. 76 g· m^-2of TN and 3.23 g· m^-2of TP） in autumn. Both of the two species had a higher absorption efficiency in TN than in TP （P 〈 0. 01 ）, and S. alterniflora had a significantly higher absorption efficiency of TN and TP than P. australis （P 〈 0. 05）. To some extent, the N/P, C/N, and C/P ratios of plants could indicate the nitrogen- and phosphorus absorption efficiency of the plants.