南麂列岛铜藻氮磷吸收特征研究

Absorption characteristics of N and P by a macroalga,Sargassum horneri,in Nanji Islands

实验室条件下测定了:(1)不同温度下,铜藻的磷吸收动力学;(2)氮磷比对铜藻氮磷吸收速率的影响;(3)不同化合态氮对铜藻氮磷吸收速率的影响;(4)成熟铜藻体内总氮总磷含量。结果显示:(1)20℃时,铜藻对磷的半饱和吸收常数最低,最大吸收速率最大;(2)氮浓度一定时,随着氮磷比值升高,铜藻对氮磷的吸收速率皆下降;磷浓度一定时,随着氮磷比值升高,铜藻对氮的吸收速率增加,对磷的吸收速率下降;(3)磷充足时,铜藻对硝氮的吸收速率随着氨氮硝氮比升高而下降,对氨氮和磷的吸收速率随着氨氮硝氮比升高先上升后下降;(4)干燥铜藻体内总氮总磷含量分别为5.70%和0.18%。

Three uptake experiments were performed under laboratory conditions： （1）Phosphate uptake kinetics of macroalga, Sargassum horneri, between 5 -25 ℃ ; （2）Effect of N： P ratio on the uptake of N and P by S. horneri ; （3） Effect of NH4 ＋ -N/NO3 - -N ratio on the uptake of N and P by S. horneri. The results were ： （ 1 ） The maximum absorption rate （ Vmax ） rises with temperature variation between 5 - 20 ℃, and reaches the max at 20℃ ; The half saturated absorption constant （Km） decreases with temperature variation between 5 -20 ℃, and reaches the min at 20 ℃ ; （2）when the N concentration was constant, the uptake rate of N and P decreases with the N： P ratio variation between 16：1 to 256：1 ; While the P concentration was constant, the uptake rate of N rises, and P decreases with the variation of N： P ratio. （3） when phosphate is adequate, the uptake rate of NO3 --N has a negative relation with NH4 ＋ -N/NO3 --N, while NH4 ＋ -N and P have a positive relation with NH4 ＋ -N/NO3 --N variation between 1：1 -8： 1, and a negative relation with that above 16： 1. （4）The TN and TP in S. horneri are 5.70% and 0.18% , respectively.