| Carin J. Corley, Gary W. Frasier, M. J. Trlica, Freeman M. Smith, and E. M. Taylor, Jr |
| Authors are former graduate research assistant, Dept. of Rangeland Ecosystem Science, Colorado State University, Fort Collins, Colo. 80523, research hydraulic engineer, USDA-ARS, Rangeland Resource Research Unit, 1701 Center Ave., Fort Collins, Colo. 80526, professor, Dept. of Rangeland Ecosystem Science, Colorado State Univ., Fort Collins, Colo. 80523, Professor, Dept. of Earth Resources, Colorado State Univ., Fort Collins, Colo. 80523, and Soil Scientist, USDA- ARS, High Plains Grasslands Research Station, 8408 Hildreth Rd., Cheyenne, Wyo., 82009. |
Abstract |
| It was hypothesized that the type and height of riparian vegetation would affect its ability to filter and retain inorganic nitrogen (nitrate-nitrogen (NO3--N), ammonium-nitrogen (NH4+-N)), and inorganic phosphorus (phosphate-phosphorus (PO4-3-P)). A rotating boom rainfall simulator was used to evaluate 2 montane riparian communities as filters for removing NO3--N, NH4+-N, and PO4-3-P nutrients from sediment laden overland flow water. One riparian community was characterized by Kentucky bluegrass (Poa pratensis L.) and tufted hairgrass (Deschampsia caespitosa (L.) Beauv.), while the second community was dominated by beaked sedge (Carex rostrata Stokes) and water sedge (Carex aquatilus Wahl.). Three vegetation height treatments were evaluated: control (natural condition), moderate treatment (clipped to 10-cm height and clipped material removed), and heavy treatment (clipped to ground level, clipped material removed, and litter vacuumed up). A 10-m wide riparian buffer zone was an efficient filter as about 84% NO3--N and 79% PO4-3-P was removed from the applied water and sediment. However, there were no consistent differences among specific vegetation height treatments or communities in the removal of N and P nutrients. |
| Key Words: Buffer strips, filtration, non-point source pollution, water quality, nutrient balance |