Analysis of Denitrification in Restored Wetlands of the North Carolina Coastal Plain.

Abstract: Over the past several decades there has been considerable effort to protect and restore wetlands throughout the United States. The USDA Conservation Effects Assessment Project (CEAP) is a multi-agency effort to quantify the environmental benefits of conservation practices.  The Mid-Atlantic Region (MIAR) CEAP wetland study is one of five regional studies undertaken as part of the national effort. This project assessed various wetland functions and services for natural, converted, and restored wetlands in the region. A portion of our efforts were focused on the organic soils of the North Carolina coastal plain. Our objectives in this study were twofold:  (1) to determine the levels of denitrification enzyme activity within the soils of these wetlands; and (2) quantify the abundance of the gene nosZ, which encodes the enzyme responsible for the reduction of the green house gas nitrous oxide to nitrogen. Our results demonstrate that restored wetland areas have overall lower denitrification enzyme activity when compared to both converted and natural wetlands. Coinciding with these results are nosZ gene abundances, with nosZ quantities significantly lower in restored wetlands. These results reveal microbial communities in potential flux after hydrological restoration from a previous agricultural setting.