Spatial Variance in Soil Organic Matter in the Lost Creek Wetland Restoration

Abstract

Long-term studies monitoring wetland hydric soil development in restoration sites have been lacking in central Wisconsin. Understanding the impact of local elevation on hydric soil development and organic matter accumulation can help inform wetland restoration practices. Following degradation due to agriculture and land use changes, the Lost Creek wetland was restored between 2005 and 2009. The restoration area is located west of Stevens Point in Portage County, WI, USA. Landscape position determines the hydrology of the location, with saturated conditions leading to hydrophytic vegetation and decreased decomposition. Changing biochemistry leads to higher organic matter content in the surface of soils as hydric soils develop. The objective of this research is to determine if elevation differences have an impact on soil organic matter and to quantify the soil organic carbon (SOC) stocks. Samples of the surface horizon for were collected in the fall semester of 2025 and were used for loss on ignition to determine organic matter percentage. With the wetland delineation and organic matter values, ArcGIS Empirical Bayesian Kriging was used to interpolate organic matter values with elevation as a factor in the predictions and Cross Validation was used to validate them. Sample points located in identified wetlands exhibited higher soil organic matter values. Ascertaining the strength of elevation as a factor in developing organic matter can be used to predict hydric soil development more accurately in the continued monitoring of restored wetlands.