Thursday, August 7, 2008

PS 69-173: The CEAP-Wetlands Project: Assessing wetland ecosystem services provided by agricultural conservation practices in the Piedmont-Coastal Plain

Diane De Steven, U.S. Forest Service Southern Research Station and Richard Lowrance, USDA Agricultural Research Service.

Background/Question/Methods Wetlands provide significant ecological “services” such as floodwater storage, water-quality improvement, wildlife habitat, and production of harvestable resources. Historically, agricultural land use was a major cause of wetland degradation and loss in the United States. Under current U.S. Farm Bill programs, environmental impacts of agriculture are mitigated by installing a variety of defined conservation practices, including some aimed specifically at protecting or recovering wetland functions. The USDA Natural Resources Conservation Service established the Conservation Effects Assessment Project (CEAP) to assess the ecological benefits derived from conservation programs and practices, and one component is evaluating wetland-related practices through regional field studies and literature syntheses. As part of the CEAP–Wetlands effort, we summarize the current state of practice implementation and research for the Piedmont–Coastal Plain.

Results/Conclusions Three relevant practice groups have been applied regionally: 1) wetland practices including restoration, creation, and habitat management, 2) conservation-buffer practices protecting adjacent wetlands, and 3) other practices that may affect wetlands indirectly, such as managing drainage or grazing. Among wetland-related practices (1 and 2), riparian forest buffers and wetland habitat management were the most commonly applied, whereas restoration and creation were less frequent. Of all wetland-related practices, only riparian buffers have been adequately studied in the region, where water-quality benefits have been well documented. In contrast, little is known about the outcomes of wetland restoration, creation, or habitat management in regional agricultural settings. The region is also experiencing rapid growth in numbers of created agricultural ponds, which may contribute to wetland quantity but not necessarily to quality. In a wetland-rich landscape such as the Piedmont–Coastal Plain, diverse hydrogeomorphic (HGM) wetland types likely differ in the ecological services provided. Documenting the HGM types involved in practice application could improve our understanding of expected benefits.