Carbon Sequestration Potential at Central Wisconsin Wetland Reserve Program Sites.

The historical shift of natural lands to agriculture and the increased soil disturbance through tillage and drainage has lead to the depletion of organic soil carbon. Farm bill programs such as the Wetland Reserve Program (WRP) have allowed wetlands to be restored or protected. Studies have indicated overall landowner satisfaction with the programs, but have not done significant ecological monitoring to determine if the restored wetlands are functioning similarly to undisturbed wetlands. This study sought to quantify the amount of organic soil carbon that has accumulated since restoration of WRP sites. Composite soil samples have been taken from twenty three different WRP sites (varying in age of restoration from 1 to 19 years) located in Central Wisconsin. All sites were at one time drained for agriculture and now have been restored as wetlands. The success of the restoration efforts, in terms of organic soil carbon content, was determined through comparison to several undisturbed wetlands within the same geologic area. The depth, bulk density, and organic carbon content were quantified for the organic rich horizons at each location. The organic soil carbon content was quantified through combustion of organic materials using a Carbon and Nitrogen Analyzer. Organic soil carbon levels varied from 0.5 % to 38 %. Regression analysis of data demonstrated a correlation between carbon levels and length of time since completion of restoration.