Author
FENSTERMACHER, D - University Of Maryland | |
RABENHORST, M - University Of Maryland | |
LANG, M - Us Forest Service (FS) | |
McCarty, Gregory | |
NEEDLEMAN, B - University Of Maryland |
Submitted to: Wetlands
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/23/2014 Publication Date: 10/8/2014 Publication URL: http://handle.nal.usda.gov/10113/59982 Citation: Fenstermacher, D., Rabenhorst, M., Lang, M.W., Mccarty, G.W., Needleman, B.A. 2014. Distribution, morphometry and land use of Delmarva bays. Wetlands. 34:1219-1228.. Interpretive Summary: Delmarva Bays are unique landscape features that occur on the Delmarva Peninsula within the Mid Atlantic Coastal Plain. These isolated wetlands are located in areas of intensive agricultural land use and they provide habitat to many rate and endangered species including certain amphibians. A significant portion of the Bays have been drained and converted from forested wetlands, to agricultural lands. We used a high resolution elevation map derived from LiDAR (Light Detection And Ranging) data to create an improved survey of Bays on the Delmarva. We now estimate that there are 17,000 Bays in the region, which is 10 times greater than earlier estimates based on aerial photography. Characterization of a subset of the Bay population showed that 80 percent of the Bays range in size from 1.1 to 14 acres with relief ranging from 1.8 and 6.6 ft. Among those characterized, 41% of the Bays have been converted to agricultural land use. These data will help us understand impacts of agriculture on the ecosystem functions related to Delmarva Bays and will lead to improved ability to restore wetlands and preserve remaining wetlands in the region. Technical Abstract: Delmarva Bays are depressional wetlands that are elliptical in shape with sandy rims, and occur mainly in the central portion of the Delmarva Peninsula within the Mid-Atlantic United States. It is postulated that they began as wind blowouts during the Pleistocene that filled with water and became elongated due to wind driven currents. Situated in a region with abundant agriculture, Delmarva Bays and other wetlands may enhance water quality by reducing nutrient and sediments levels in local waters. A significant portion of these features, have been drained and converted from forested wetlands, to agricultural lands. Bays were located and counted using LiDAR data. We now estimate that there are 17,000 Bays on the Delmarva Peninsula, which is an order of magnitude greater than earlier estimates based on aerial photography. Using a stratified sampling scheme based on Bay density, morphometric parameters of 1494 Bays were measured from the LiDAR data and their land use was assessed from aerial photography. Eighty percent of the Bays range in size from 0.46 to 5.68 ha, have a relief ranging between 0.55 and 2.02 m, and have a major to minor axis ratio between 1.08 and 1.65. Among those sampled, 41% of the Bays have been entirely converted to agriculture and another 29% have been partially converted. There are 29% of the Bays that retain full natural vegetative cover, although these may have experienced some hydrological disturbance. |