Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/20/2003
Publication Date: 11/3/2003
Citation: Lowrance, R.R., Hubbard, R.K., Bosch, D.D., West, L.T., Vellidis, G., Potter, R. 2003. Soils control nutrient filtering in coastal plain riparian ecosystems. Soil Science Society of America Annual Meeting. Abstract 507-600341, SSSA Proceedings (Compact Disk) Interpretive Summary:
Technical Abstract: Forested riparian ecosystems typically have waterborne nutrient outputs that are an order of magnitude less than outputs from adjacent agricultural fields. This occurs despite riparian ecosystems being responsible for most of the stream flow generation within a watershed. Studies of soil processes in Coastal Plain riparian ecosystems have shown that a combination of biotic and abiotic soil processes help to limit the nutrient output from riparian ecosystems. Solute movement into riparian zones occurs as both saturated and unsaturated flow. Although saturated flow brings generally larger volumes, unsaturated flow has the potential to bring higher concentrations of solutes such as nitrate. Denitrification is important for nitrate removal with most riparian soils studied responding to nitrogen additions without the need for additional carbon or water inputs as a stimulus. Denitrification is generally highly stratified from surface to subsurface and is higher in very poorly drained riparian soils than in poorly drained or moderately well drained ones. The most important mechanism for P removal is to provide rapid infiltration with co-deposition of particles. Soil associated with the litter layer can be used to estimate the amount of dissolved P adsorption from direct surface runoff. In mature forest buffers, soil processes may become more important for nutrient filtering, especially as net primary production decreases. As more agricultural areas are restored to forested riparian buffers, evaluation of the long-term changes in soil properties will be necessary to provide an accurate assessment of the water quality impacts of buffers.