High-Precision Elevation Model to Evaluate the Spatial Distribution of Soil Organic Carbon in Active Floodplains

Abstract

This study examines the spatial distribution of soil organic carbon (SOC) and other properties in soils in active floodplains using a high precision digital elevation model (DEM) and geographic information system. Floodplain microtopography may influence wetland hydrology and the physical and chemical properties of soil, thus affecting the balance of plant nutrients in this riverine environment. The selected sites were composed of three floodplains dominated by a forest consisting of silver maple (Acer saccharinum L.) with some green ash (Fraxinus pennsylvanica Marsh.). These floodplains were frequently subject to floods during spring (and also in summer and fall) that create dynamic processes in the formation of alluvial soils and in the structure and composition of floodplain vegetation. The maximum and minimum SOC rates that were obtained ranged from 0.05% to 3.16%, with median values of 0.87%. In addition, no preferential pattern was detected on SOC spatial distribution in floodplain soils even when a high precision digital elevation model was used to define floodplain microtopography. Frequent floods and vertical aggradation maintain the soil in an immature state and cause a depletion of the soil’s organic carbon content.