广西合浦榕根山小型海草床的群落演替及其保护和修复研究

2001～2011年现场调查和监测广西合浦沙田镇附近的榕根山海草床,研究小型海草床的群落演替及其保护和修复.结果发现,从2001年到2005年,榕根山海草床的面积从13.3 hm2增加到17.1 hm2,但是2006年以后海草床的面积开始减少,至2011年面积已减少到不足1 hm2.海草的群落也由矮大叶藻(Zostera japonica)单一优势种群落演替为贝壳喜盐草(Halophila beccarii)优势种群落,引起海草的盖度、生物量和茎节密度明显变化.榕根山海草床衰退主要是由于海水水质变化、互花米草(Spartina alterniflora)入侵,以及鸭子放养引起,保护和修复榕根山海草床要控制海草床周边互花米草扩散和整治岸边的畜禽养殖及污水排放,同时还要加强对海草床的监测和保护及修复研究,探索海草与互花米草的竞争机制及互花米草控制方法,为小型海草床的保护和修复提供理论和技术支持.

Community Succession and Preventive Countermeasures of Small Seagrass Bed in Ronggenshan of Hepu Guangxi

As incidentally influenced by environmental change,community succession and decline occurred in small seagrass bed.Based on the data of investigations from 2001 to 2011,this research selected a small seagrass bed of Ronggenshan seagrass bed, which was near the Shatian town in Guangxi,to study community succession and its reasons in small seagrass bed.Seagrass area in Ronggenshan ranged from 13.3 hm² to 17.1 hm² from 2001 to 2005.However,it decreased from 2006,and was less than 2 hm² from 2009 to 2011.The community of the seagrass had changed, that is,Halophila beccarii took the place of Zostera japonica as the new dominated species.As a result, the coverage,biomass and branching density of seagrass had changed.In order to protect small seagrass bed,pertinence advices have been discussed for the Ronggenshan seagrass bed as well as for other seagrass beds to refer.