|Lowrance, Robert - ARS, SWRC, TIFTON, GA|
|Williams, Randall - ARS, SWRC, TIFTON, GA|
Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: April 22, 2005
Publication Date: May 12, 2005
Citation: Graff, C.D., Sadeghi, A.M., Lowrance, R.R., Williams, R.G. 2005. Sensitivity of the riparian ecosystem management mode (REMM) to perturbation in vegetation parameters: Evaluating the effectiveness of specific conservation practices [abstract]. BARC Poster Day. Technical Abstract: The Riparian Ecosystem Management Model (REMM) was developed by ARS scientists in Tifton, GA, to evaluate the fate of nutrients and sediment through a riparian buffer up to the edge of a stream. A one-at-a-time sensitivity analysis was performed on REMM to evaluate the effects changing buffer characteristics have on modeled N, P and sediment in surface and ground water. Vegetation characteristics such as rooting depth, LAI, and plant height, along with some physical buffer characteristics such as slope and Manning's N, were varied and compared to a ‘base case’ scenario. Outputs were not sensitive to changes in plant height or LAI but moderately sensitive to changes in SLA. Nutrients in surface water were only sensitive to changes in rooting depth when roots were not allowed to grow below the top-most layer of the soil profile. Sediment yield and dissolved nitrate in surface water were the most sensitive to changes in Manning’s N, while other soil physical characteristics such as surface roughness surface condition, and % bare soil had no effect on model outputs. Dissolved surface nitrate, organic P, and dissolved subsurface nitrate were all moderately sensitive to changes in permeability rate and the slope of the buffer. Results indicate that vegetation characteristics do not directly play a role in the physical transport of nutrients and sediment in REMM, and therefore utilizing this model to evaluate load reductions from specific plant types may be ineffective.