Differences in crab burrowing and halophyte growth by habitat types in a Korean salt marsh

Crabs and halophytes are important indicators of soil composition and fertility in salt marsh ecosystems. Many previous studies have examined the effects of crab excavation on soil properties, but little is known about the combined effects of crabs and halophytes on salt marsh soils. The purpose of this study was to identify the distribution of halophytes and crabs in a macrotidal salt marsh, and to determine effects of the combination of crabs and halophytes on the physicochemical properties of soils. Vegetation structure and soil properties in relation to seed dispersion distance and habitat type were analyzed using Kruskal-Wallis tests, Cluster Analysis (CA), and Principal Component Analysis (PCA). Plant biomass and height of individual marsh plants tended to be higher at distances > 1 m from stands of parent plants. Crabs preferred habitats with high vegetation cover. Low densities of burrowing crabs and halophytes also caused considerable changes in soil properties. The combination of crabs and halophytes increased the spatial variability of physicochemical parameters in these salt marsh soils. Thus these combinations may be important to a complete understanding of plant distribution and soil nutrient cycling in salt marsh ecosystems.