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

摘要

The Riparian Ecosystem Management Model (REMM) was used to simulate nitrogen (N), phosphorus (P), and carbon (C) cycling and transport in a Coastal Plain riparian buffer system near Tifton, Georgia. The riparian buffer consisted 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 period were compared to measured values for the same time period at the research site. In general, simulated water table nutrient concentrations were within one standard deviation of observed values on an annual basis. Surface runoff loads exiting 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 the surface runoff differences (observed vs. simulated) were large in relative terms, the overall trends within the riparian buffer were generally well-represented and differences were not large in absolute terms. Simulated values for one of the most important processes responsible for effectiveness of riparian zones — denitrification, were within the range of those observed. Much of the temporal dynamics of the observed data were also captured in the REMM simulations. Certain constraints of the model use are discussed, but REMM appears to be useful for representing many of the specific processes and general trends in riparian ecosystem buffers.