Comparison of Two Wetlands for Differences in Composition due to Age of Seeding
The Iowa Conservation Reserve Enhancement Program (CREP) wants to remove nitrogen and other agricultural chemicals before cropland tile-drainage water enters rivers and streams. This is done by the restoration or construction of wetlands in areas of high need for removal of excess nutrients. The goal is to protect drinking water supplies and reduce hypoxia in the Gulf of Mexico. The objective of this study was to survey wetlands across the north central region of Iowa for the success of seeding. These wetlands range in age from one to ten years and have been seeded at varying intervals. Each wetland received an identical seed mixture. We hypothesized that older wetlands would have a greater average shore to emergent edge width (littoral zone), less species diversity, and a predominance of monocultures. Vegetation surveys were completed using: transects and quadrats to estimate percent coverage, measuring the distance from shore to the emergent edge, and identify species. Preliminary results indicate that older wetlands are better at reducing levels of targeted nutrients from the watershed. This study can be used to inform future management strategies and the implementation of wetlands as a means to enhance water quality.