Small-scale spatial variability of soil properties in a Korean swamp

Wetland soils have distinctive biogeochemical processes and ecosystem functions. Therefore, knowledge of wetland soils is important for conserving and rehabilitating wetland ecosystems. We investigated soil properties and their spatial variability in a temperate swamp and compared them with those of an adjacent upland within a small-scale watershed in Korea. Soil water content and carbon and nitrogen concentrations were two- to four-times higher in wetland than in upland soils. Soil water content and organic matter, which represented a large proportion of the variability of wetland soil properties, could be considered primary soil quality indicators for wetland soils. Wetland soils were characterized as having high spatial variability and moderate to strong spatial autocorrelation within a 30- to 50-m range. Nutrient availability was mainly regulated by soil water content and organic matter, not by pH, which had low variability and showed an independent pattern. These findings imply that wetland soils should be surveyed using an appropriate sampling design to determine characteristics of spatial variability in soil quality indicators in wetlands. Reference values of wetland soil properties reported from this study are expected to contribute to wetland conservation and rehabilitation.