不同氮磷比值下浒苔与石莼的竞争作用研究

The competition between Ulva prolifera and Ulva lactuca under different N/P

近年来,海水富营养化导致近海海域大型海藻过量繁殖,成为世界性的环境问题。自2007年以来,浒苔绿潮在黄海海域连续暴发,造成巨大经济损失。为探究浒苔大规模暴发与氮磷比值(N/P)的关系,及其与其他大型绿藻在不同N/P下的竞争机制,研究了浒苔(Ulva prolifera)与石莼(Ulva lactuca)在不同N/P下单独培养和共培养时的生长情况,探究了浒苔及石莼生长的变化;结合苏北浅滩海域现场N/P的调查结果,分析了浒苔绿潮暴发的可能机制。研究结果表明:(1)浒苔单独培养时,在一定范围内高N/P能促进浒苔的生长,氮对于浒苔的影响大于磷。(2)石莼单独培养时,低N/P下石莼长势最好,但改变N/P对石莼的影响并不显著。(3)浒苔和石莼共培养时,浒苔生长受到了一定限制,低N/P下浒苔生长受限更显著。(4)苏北浅滩海域高N/P更适合浒苔的生长,可能是浒苔绿潮能够大规模暴发的原因之一。

In recent years,the eutrophication of seawater has led proliferation of large seaweeds in offshore waters,becoming a worldwide environmental problem.Since 2007,the green tide of Ulva prolifera has continuously broken out in the Yellow Sea,causing huge economic losses.In order to investigate the relation between macroalgae and the ratio of nitrogen to phosphorus(N/P),and the competition mechanism with other macroalgae,we studied the growth of U.prolifera and U.lactuca when pure culture and co-culture.The results showed that:(1)When U.prolifera was pure cultured,the higher or lower N/P can promote the growth of U.prolifera.(2)When U.lactuca was pure cultured,the effect of the N/P on U.lactuca is not obvious.(3)U.prolifera growth was inhibited to some extent under the different N/P conditions when U.prolifera and U.lactuca were co-cultured,and the lowest N/P group was affected the most.(4)The N/P in the Subei Shoal is more suitable for the growth of U.prolifera,which may be one of the main reasons for the large-scale outbreak of U.prolifera green tide.