The Ecology Study Of Macrobenthos Community In Dongtan Of Chongming Island

The paper studied the macrobenthos community in Dongtan of Chongming through several times.The paper's emphases are below: the structure (species,density,biomass and biodiversity),the mechanism of forming,the factors of determination,and the relations among the space heterogeneity,vegetation ,the location of tide flat and wetland succession.Major conclusions from the research are the below: 1 , The structure of macrobenthos community in DongtanBased on the data collected from four sampling on the spot on the macrobenthos community in the Dongtan from Winter to Autumn in 2005, a total of 32 species were identified.There were 13 species molluscs, 11 species crustaceas,6 species annelids,one species little insect ,and one another species.The percent of them were 40.6% ,34.4%, 18.7%, 3.1% and 3.1%.The species of winter,spring,summer,and autumn were 17, 19, 21, 19.They were divided into three categories,i.e.,fresh water species,brackish water species and sea water species,which reflected the ecological characteristics of macrobenthos community in Dongtan. There were many costly species of macrobenthos in Dongtan.For example , Eriochier sinensis, Helice tridens tientsinensis, Sesarma dehaani, Exopalaemon carinicauda, Corbicula fluminea, Potamocorbula ustulata, Bullamya purificata, Sinonovacula constricta,and so on. 2,The relation between macrobenthos community and vegetationThe species of macrobenthos was following that : Scirpus mariqueter(17) , Phragmites australis(12) > Spartina alterniflora(10)>bare tidal flat(9).The mollusca was dominant in bare tidal flat,for example, Rissoina sp., Bullamya purificata; Rissoina sp., Moerella iridescens,and Hyoplax deschampsi were the dominant in Scirpus mariqueter; Helice tridens tientsinensis, and Sesarma dehaani were dominant in Phragmites australis. Assiminea latericera , Limnodrius hoffmeisteri and Sesarma dehaani were dominant in Spartina alterniflor.The density of macrobenthos was following that : Scirpus mariqueter >Phragmites australt> Spartina alterniflora> bare tidal flat.There were many Rissoina sp. in Scirpus mariquete,so the density of macrobenthos in Scirpus mariquete was the highest. The biomass of macrobenthos was following that : Scirpus mariqueter>Phragmites australi>Spartina alterniflora>baie tidal flat. The biodiversity of macrobenthos was following that : Scirpus mariqueter >Phragmites australi> Spartina alterniflora>bare tidal flat. The species of bare tidal flat was more than Spartina alterniflora,but the value of equitability in bare tidal flat was higher than Spartina alterniflora,so the value of biodiversity in bare tidal flat was higher than Spartina alterniflora.The crab in Scirpus mariqueter made many cavities which enhance the heterogeneity.So the...