인공구조물에 따른 조간대 대형저서동물 군집 변화

Abstract

The wetlands including tidal flats have been considered as an interactive system between biological and non-living environment and a crucial role in the survival of numerous fauna and flora living within wetland, suggesting the construction of artificial tidal flats considering the creation and restoration of tidal flats. Artificial structures such as seaweeds and timber fence were designed to increase the activation of creation and restoration of tidal flat. However, little is known about that whether the artificial construction is affected to the macrobenthic community structure. On a intertidal flat in front of Iwon Dike, west of Korea, the effect of the artificial structures on macrobenthic community was studied throughout the years 2001-2005. In total, 137 macrobenthic species were recorded during this study, with crustaceans (47%), polychaetes (18%), and molluscs (27%) having the highest species diversity. The density of polychaetes comprised over 50% of the total density, followed by gastropods (38%) and crustaceans (11%). Macrobenthic species composition was similar between artificial and natural sites, with several common dominant species found at the beginning of the experiment, but differing after 7 months. The gastropod Umbonium thomasi, the most dominant species, appeared at all sites within 1 month after the start of the experiment, but disappeared in the artificial sites after 7 months, suggesting disturbance by the environmental variance. The number of species and diversity (H') varied significantly within regions at the beginning of the experiment, but no difference was observed after 7 months. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure between the experimental and natural areas. The community structures were mainly influenced by U. thomasi. The community structures in the artificial sites were affected by variable environmental factors, which changed over time. We observed no significant