Ecological Study On Macrobenthos Community In Shazhou Wetland In The South Of Minjiang River

The paper studied the macrobenthos community in different habitats of Shupaisha Wetland in South Branch of the Oujiang Estuary in three habitats forms, including mangrove habitats, Spartina alterniflora habitats, and naked beach habitats through several times. Based on the survey data of abundance and biomass of macrobenthos, several studies were conducted in three habitats forms, including researches on species composition, the dominance, spatial and temporal variation of the density and biomass, and the relationship of macrobenthos distribution to quality of sediment. Furthermore, assemblage structure and diversity of macrobenthos, stability of the community, and the relationship of diversity of species to sediment quality was discussed. Finally, the paper analysised group species composition, spatial and temporal distribution, diversity characteristics, and the relationship of functional group to sediment quality of macrobenthos functional. The main results of this research were as follows:A total of 48 macrobenthos species were recorded in three habitats forms, i.e., mangrove habitats, S. alterniflora habitats, and naked beach habitats, belonging to 40 genus, 31 families, 15 classes, and 5 phyla. The species number were the highest in mangrove habitats(38), followed by S. alterniflora habitats(28) and naked beach habitats(25). The one-way ANOVA analysis showed that species number has no Significant difference between seasons(F=1.088,P=0.497). However, species number had Significant difference between habitatss(F=7.268,P=0.013). There were some differences in the dominant species of macrobenthos in different habitats. Cerithidea largillierti, C. cingulate, Assiminea brevicula, A. latericea, Uca arcuate, Helice tientsinensis, Chiromantes haematocheir, Metaplax longipes and Periophthalmus modestus were the dominant species in mangrove habitats. C. largillierti, A. brevicula and A. latericea were the dominant species in S. alterniflora habitats. C. largillierti, A. brevicula, A. latericea, M. longipes and P. modestus were the dominant species in naked beach habitats. The average inhabitant density and biomass were the highest in mangrove habitats, followed by S. alterniflora habitats and naked beach habitats. The canonical correspondence analysis of the quality of sediment and macrobenthos in different habitats showed that C, S, Ge, As, Oil and Hg impacted on macrobenthos distribution in the mangrove habitats; S, C, Cr, Oil, Cu, Ge, Pb and Zn impacted on the macrobenthos distribution in S. alterniflora habitats; S, Ge, C, As, Hg, Cu, Zn, Gr, Pb and Oil impacted on the macrobenthos distribution in naked beach habitats.Shannon Wiener diversity index(H'), Pielou uniformity index(J') and Margalef species richness index(D) of macrobenthos changed largely in different habitats, and the species diversity was highest in mangrove habitats. The one-way ANOVA analysis showed that shannon Wiener diversity index and margalef species richness index had Significant difference among habitats(F= 5.135,P=0. 033; F=5.152,P=0.032), and the rest were not significant. The paerson correlation analysis indicated that species diversity index of macrobenthos and sediment quality had no significant correlation in different habitats. The G-F analysis indicates that the G- index and F- index were highest in mangrove habitats, however, G-F index was highest in S. alterniflora habitats. On the macrobenthos community level clustering found that in different habitats of macrobenthos community was significant difference. In autumn, winter and spring in different habitats were clustered into three groups, and the summer were clustered into four groups. According to the ABC curve analysis the macrobenthos community in different habitats were subject to varying degrees of interference.This paper divided the macrobenthos into five functional groups, including plankton eaters, plant eaters, predator, omnivore, and clastic predators, according to the feeding habit. The five functional groups in different habitats of inhabiting density and biomass were different. Macrobenthos functional group diversity in mangrove habitats was significantly higher than partina alterniflora habitats, and naked beach habitats. The canonical correspondence analysis of the quality of sediment and macrobenthos functional group in different habitatss showed that Oil, Cu, Pb, Hg and As impacted on macrobenthos functional group in mangrove habitats; C, S, Cr, Cu, Pb and Zn impacted on macrobenthos functional group in partina alterniflora habitats; Oil, C, S, Pb, Zn and As impacted on macrobenthos functional group in naked beach habitats.