Properties and Processes Effecting Wetland Soil Function in Restored and Natural Wetlands On the Delmarva Peninsula.

Within the past 20 years, there has been a shift in wetland conservation efforts past protection of existing wetlands to the restoration of previously disturbed wetlands. Through the Wetland Reserve Program, the USDA-NRCS has restored over 2.6 million acres of private land intending that they be functionally equivalent to natural wetlands. The primary method of restoration has been “scraping,” or the physical lowering of the surface to the water table through use of heavy machinery, often resulting in lower carbon stocks and increased compaction. This project will seek to assess whether these restored wetlands are functioning as intended or are negatively impacted by the restoration method. As part of the Mid-Atlantic CEAP effort, ten restored and five natural, depressional, freshwater wetlands have been selected for study. These wetlands demonstrate seasonal fluctuations and spatial variability in saturation, and various properties will be assessed along a hydrological and topographical gradient from the seasonally ponded wetland zone to the upland. Properties of interest include extent of soil compaction, carbon and nitrogen stocks, OM decomposition rate, and the degree of reducing conditions. Decomposition rate will be determined by measuring mass loss from buried wooden stakes. IRIS tubes will be used to compare reduced soil conditions among sites. Soil penetration resistance will be used as an indicator of soil compaction and will be measured to a depth of 45 cm. Comparisons will be made among the various wetland sites as well as across the hydrological gradient within each wetland. Preliminary data will be presented.