An observational, geostatistical, and experimental assessment of edaphic properties and processes in created, restored and natural wetlands of the southeastern coastal plain

Current monitoring of created (CW) and restored wetlands (RWs) does not require any assessment of soil properties. This is a cause for concern because soil forms the foundation of these developing ecosystems and inadequate soil properties can be detrimental to wetland function. In response to these concerns, my dissertation utilized observational, geostatistical, and experimental approaches to assess edaphic properties and processes in CW/RWs and natural wetlands (NWs) of the southeastern Coastal Plain.; I hypothesized that the spatial variability of soil properties in CW/RWs would be less than that of paired NWs, as prior-land-use and mitigation activities tend to homogenize wetland soils. Moran's I analysis revealed that, for certain soil properties, significant fine-scale autocorrelation present in NWs was absent from CW/RWs. Frequency distributions, Cochran's tests, and interpolated contour maps indicated that certain soil properties, such as nitrate, were considerably more homogeneous in CW/RW than NW plots across four hydrogeomorphic subclasses. For other properties, such as soil organic matter, there were no consistent differences in patterns of variability between CW/RW and NWs or across subclasses. I also illustrated how two riparian NWs with similar vegetation and hydrology had considerably different phosphorus (P) sorption capacities and associated spatial distributions. At both sites, after accounting for autocorrelation, variability in P sorption was best explained by oxalate extractable aluminum. Uniform or random sampling designs would have failed to capture these plots' rich spatial structure.; As a lack of organic matter and homogeneous edaphic conditions appear to be two main limitations of CW/RWs, I concluded with an assessment of two strategies designed to ameliorate such conditions: organic amendments and microtopographic reestablishment. I determined the optimal range of organic amendments at a CW to be between 60 and 110 Mg compost ha-1. Such amendment levels stimulated denitrification with only slight decreases in P sorption. By the third growing season after microtopographic reestablishment at a RW, inorganic nitrogen was highest in the hummocks, species richness was highest in flats, and aboveground biomass was highest in hollows. The ability to mimic the complexities of NW soils is arguably the next great challenge of wetland creation and restoration.