Spatial Macrobenthos Habitat on Ganghwa Tidal Flat, Korea: Part I - Spatial Relationship between Potamocorbula laevis and Spatial Variables

This paper describes the spatial relationship between Potamocorbula laevis and spatial variables on an intertidal flat at Ganghwa, Korea, which is the largest tidal flat on the west coast of South Korea. In total, 5,700 Potamocorbula laevis were counted at 30 sampling locations, making it the dominant species in the study area. Eight spatial variables in the habitat were examined: distance from a channel network; density of channel network; elevation; slope; aspect; and the amounts of silt, clay, and sand on the tidal flat. The spatial distribution of Potamocorbula laevis in relation to each spatial variable was measured using a frequency ratio (FR) based on a geographic information system (GIS). The results indicate that Potamocorbula laevis prefer areas with an elevation of 407-498 m, less than 14 degrees of slope, a north aspect, within 30 m of a channel, near a high density of channels, and in areas with more silt and clay and less sand. The FR is a probability ratio that quantitatively describes specific relationships. The data provide important information for understanding intertidal estuarine ecosystems, and can be used as a baseline for comparing spatiotemporal macrobenthos distributions in the future.