浒苔对NH+4-N与NO-3-N吸收的相互作用

在国内首次研究了大型海洋绿潮藻浒苔(Ulva prolifera)对NH4+-N与NO 3--N两种氮源的选择吸收作用。结果表明:当两种氮源等浓度比例存在时,随着NH4+-N与NO3--N浓度升高,藻体对NH4+-N的吸收速率逐渐升高,而对NO3--N吸收受到抑制;当NO3--N和NH 4+-N高浓度比存在时,藻体对NH4-N的吸收速率随着NO3--N/NH4+-N比例的升高和NH4-N浓度的下降而降低;当NO3--N和NH4+-N低浓度比存在时,藻体对NH+4-N保持较高的吸收速率,而对NO3--N的吸收效率随着NO3--N浓度的降低而降低;浒苔具有同时利用水体中较高浓度的NH+4-N和NO3--N的能力,只有当NH4+-N或NO3--N浓度较低时,才以吸收相对应的氮源为主。这说明浒苔能够快速、大量地吸收水体中氮源,为爆发性增殖贮备物质条件。同时,即便两种氮源同时存在,浒苔对NH+4-N的吸收速率也远高于对NO3--N的吸收速率,因此,控制NH4+-N的大量输入仍是预防浒苔绿潮爆发的关键。

The interaction between NH+4-N and ?NO-3-N in nitrogen uptaking by Ulva prolifera

The nitrogen uptake by Ulva prolifera in the forms of NH⁺₄-N and NO^-₃-N was investigated. With increasing concentrations of the total nitrogen (NH⁺₄-N/NO^-₃-N= 1), the absorption rate of NH⁺₄-N was increased, but the absorption rate of NO^-₃-N? was inhibited. With the ratio of NO^-₃-N / + NH⁺₄-N > 1, the absorption rate of NH⁺₄-N decreased with the increase of the ratio of NO^-₃-N/NH⁺₄-N. With the ratio of NH⁺₄-N/ NO^-₃-N > 1, the absorption rate of NH⁺₄-N was significantly higher than that of NO^-₃-N by U. prolifera. NH⁺₄-N and NO^-₃-N can both be absorbed by U. prolifera; the species with higher concentrations will be the main N resource. Therefore U. prolifera can quickly uptake the nitrogen in water for blooning. Moreover the absorption rate of NH⁺₄-N of U. prolifera.was significantly higher than that of NO^-₃-N in the presence of NH⁺₄-N and NO^-₃-N. Hence, to prevent the Green Tide blooming, it is key to control the importing of NH⁺₄-N.