不同滩涂促淤围垦方式对大型底栖动物群落的影响

INFLUENCE OF DIFFERENT TIDELAND RECLAMATION WAYS ON MACROBENTHOS COMMUNITU

滩涂促淤围垦会对大型底栖动物造成一定程度的影响,但关于不同促淤方式对大型底栖动物的影响未见有报道。以长江口浦东机场外侧滩涂促淤区为研究对象,分析吹沙促淤区域和抛坝促淤区域中大型底栖动物的分布特点。结果显示:大型底栖动物在抛坝促淤区和吹沙促淤区年均密度分别为(835.98±572.41)ind./m^2和(52.85±12.04)ind./m^2,年均生物量分别为(135.25±63.99)g/m^2和(40.82±6.84)g/m^2,单因素方差分析显示,两者存在显著性差异(P<0.05),进而表明不同促淤方式对大型底栖动物的密度和生物量影响不同。CLUSTER聚类和MDS排序图说明吹沙促淤区和抛坝促淤区断面之间的大型底栖动物群落组成存在差异性。对各断面间群落相似性矩阵进行SIMPER分析表明河蚬、光滑狭口螺和谭氏泥蟹为两种区域共有优势种,其贡献度分别为56.10%、10.81%、9.62%,且三者在吹沙促淤区中的密度分布少于抛坝促淤区。研究表明泥沙淤积的快慢程度是影响促淤围垦区内大型底栖动物分布的重要因素。

Effects of tideland reclamation on composition of macrobenthos have been confirmed by many reports.However, few studies were conducted on the impacts of reclamation ways on macrobenthos. In this study, we chose the tidal flat silting zone outside Pudong airport as the investigated subject to explore the different distribution characteristics of macrobenthos in a sand blowing siltation zone and a dike building siltation zone, respectively. Results indicated that the annual average density and biomass of macrobenthos were（835.98±572.41） ind./m^2 and（135.25±63.99） g/m^2 in the dike building siltation zone, whereas those were（52.85±12.04） ind./m^2 and（40.82±6.84）g/m^2 in the sand blowing siltation zone.One-way ANOVA analysis showed that there were significant differences between these two areas（P0.05）, indicating that reclamation ways had different effects on density and biomass of macrobenthos. Clustering and sequencing diagram showed that there were significant differences between the sand blowing siltation zone and dike building siltation zone in terms of macrobenthos composition. SIMPER analysis indicated that Corbicula fluminea, Stenothyra glabra and Iiyoplax deschampsi were the dominant species in those two areas, with the contributions of 56.10%, 10.81%, and 9.62%,respectively. Density of Corbicula fluminea, Stenothyra glabra and Iiyoplax deschampsi in the sand blowing siltation zone were less than those in the dike building siltation zone. The results imply that the rate of sedimentation was the key factor for the distribution of macrobenthos in the siltation and reclamation zones.