不同发育时间的互花米草盐沼对大型底栖动物群落的影响

2004-2006年对长江口崇明东滩湿地芦苇(Phragmites australis)盐沼和不同发育时间的互花米草(Spartina alterniflora)盐沼的大型底栖动物群落特征进行分析研究.结果表明:互花米草盐沼发育初期,大型底栖动物群落以腹足类为主,物种丰富度(D=2.18)和多样性(H′=2.19)均低于芦苇盐沼(D=2.61, H′=2.29);随着时间的推移,互花米草与本地生物逐渐形成互动和稳定的格局,大型底栖动物群落组成中多毛类的种类逐渐上升(由3种变为6种),物种数和物种丰富度也上升,从而逐步形成新的大型底栖动物群落,物种丰富度(D=2.70)和多样性(H′=2.48)逐渐上升并高于芦苇盐沼(D=2.19, H′=2.09);从大型底栖动物群落的重新形成到稳定阶段,需要若干年的时间.

Influence of Spartina alterniflora salt marsh at its different development stages on macrobenthos

In 2004-2006,the community characteristics of macrobenthos in Phragmites australis salt marsh and in Spartina alterniflora salt marsh at its different development stages were investigated in Chongming Dongtan of Yangtze River estuary.At the early development stages of S.alterniflora salt marsh,macrobenthos were mainly composed of gastropod,and the species richness(D=2.18) and diversity(H'=2.19) were lower than those in P.australis salt marsh(D=2.61,H'=2.29).With the shift of time,S.alterniflora gradually interacted with native species and formed stable pattern,and the species numbers of polychaeta increased from 3 to 6.The species number and abundance of macrobenthos increased,and a new pattern of macrobenthos community was formed.The species richness(D=2.70) and diversity(H'=2.48) of macrobenthos were higher in S.alterniflora salt marsh than in P.australis salt marsh(D=2.19,H'=2.09).It would take several years for the establishment of new and stable macrobenthos community.