RIPARIAN ECOSYSTEM MANAGEMENT MODEL (REMM): II. TESTING OF THE WATER QUALITY AND NUTRIENT CYCLING COMPONENT FOR A COASTAL PLAIN RIPARIAN SYSTEM

Abstract

The Riparian Ecosystem Management Model (REMM) was used to simulate nitrogen (N), phosphorus (P), andcarbon (C) cycling and transport in a Coastal Plain riparian buffer system near Tifton, Georgia. The riparian bufferconsisted of zone 3 (grass next to a row crop field); zone 2 (mature pine forest downslope from zone 3); and zone 1(hardwood forest downslope from zone 2, adjacent to a stream). Uncalibrated simulation results for a five-year periodwere compared to measured values for the same time period at the research site. In general, simulated water tablenutrient concentrations were within one standard deviation of observed values on an annual basis. Surface runoff loadsexiting zone 3 for most N and P forms were simulated within one standard deviation of the observed. In contrast zone 2,surface runoff loads for inorganic N species were an order of magnitude lower than observed. Although some of thesurface runoff differences (observed vs. simulated) were large in relative terms, the overall trends within the riparianbuffer were generally well-represented and differences were not large in absolute terms. Simulated values for one of themost important processes responsible for effectiveness of riparian zones denitrification, were within the range of thoseobserved. Much of the temporal dynamics of the observed data were also captured in the REMM simulations. Certainconstraints of the model use are discussed, but REMM appears to be useful for representing many of the specificprocesses and general trends in riparian ecosystem buffers.