1a.Objectives (from AD-416):
Assist NRCS in providing science-based data, results, and information to routinely inform conservation decisions affecting wetland ecosystems and the services they provide. Assist NRCS in developing a collaborative foundation that facilitates the production and delivery of scientific data, results, and information.
1b.Approach (from AD-416):
The funds used for in-house efforts will focus on assessments of denitrification in the wetland sites. The denitrification enzyme assays will be done on the approximately 60 evaluation sites. Greenhouse gas chamber analyses will be done on a select number of sites via a static chamber and a photoacoustic analyzer. The East Carolina effort will be done via an SCA focused on a site rating system. The Mitchell Ecology effort will be done via an SCA focused on amphibian evaluations. In both cases, the SCA evaluations will consider potential connections with the conditions for and the level of denitrification.
This research supports project objective 3: Develop practices and technologies that enhance denitrification with minimized nitrous oxide emissions in water table managed fields and wetlands.
There were forty-eight total sites sampled from wetlands in Delaware, Maryland, Virginia, and North Carolina. Each site was sampled at 4 landscape elevations (wettest to driest). The sites were sampled three times over a three-year period. The denitrification component of nitrogen cycling within these wetlands was assessed by measuring denitrification enzyme activity (DEA). DEA values varied significantly with relative elevation and management. The DEA response to non-limiting nitrate-nitrogen additions also varied significantly with relative elevation and management. The percentage of denitrification as nitrous oxide (a potent greenhouse gas) was different with relative elevation and management. The restored wetlands were more similar to the natural wetlands in all aspects of DEA.