THE MACROBENTHIC COMMUNITY AND NICHE ANALYSIS OF CREEKS IN DIKED TIDAL FLAT AT LINGKUN ISLAND, WENZHOU BAY

From Nov. 2003 to Aug. 2004, the macrobenthic community and niche analysis at creeks in diked tidal flat in 1997 were studied at Lingkun Island, Wenzhou City, Zhejiang Province. The result showed: Altogether 33 species belonging to 20 families, 8 classes and 6 phyla were collected, most of which were arthropods and the mollusks. In different habitats of the creeks (the grass flat, the bank of creek and the bottom of the creek), the composition and abundance of the macrobenthos were different from one another. There were 18 species in the grass flat, most of the grass flat species were arthropods and mollusks, 23 species in the bank of the creek. Most of the bank species were arthropods, mollusks and polychaetes, and 13 species at the bottom of creek, most of the bottom species were crustaceans and arthropods. The Margalef. s species diversity index: BaC > GF > BoC; the Shannon-Wiener. s index: BaC> Boc > GF; thePielou. s index: BoC > BaC > GF; the Simpson. s index: GF > BoC > BaC. Based on the data of the four times extraction of the density of macrobenthic species using the Hierarchical Cluster of between-groups linkagemethod and the Non-matricMultidimentional Scalingmethod, the 21 specieswere classified in-to three groups: the widespread species, the familiar species at bank of creek, the rare species. The species of different groups had different niche overlap characters. The results revealed that the niche breadth and the niche overlaps reflected the species distribution, the quantity of characters and the species ability to utilize the environmental resource.