lowprj1

Problem:

Agriculture continues to be a major reason for nonpoint source pollution in the United States. Sediment, excessive nutrients, and habitat modification are among the sources of nonpoint pollution which agriculture can produce. Riparian ecosystems are known to be effective in reducing the impact of these nonpoint source pollutants. USDA has developed a three zone buffer specification which will be applied extensively through the Conservation Reserve Program and other state and federal cost share programs. Testing of the three zone buffer system needs to be done on a larger scale than has previously been done. Better techniques are needed to manage, restore, and enhance riparian ecosystems for nonpoint source pollution control.

Approach:

The Riparian Ecosystem Management Model (REMM) has been developed as a tool to determine the water quality functions of riparian ecosystems of different size, vegetation, soils, and management. REMM allows simulation of a wide variety of riparian ecosystems over long time periods (100 years +) in order to determine the effectiveness of the water quality functions of the riparian buffer. REMM is being tested with data from riparian ecosystem studies in the southeastern Coastal Plain near Tifton, GA and with data from other sites. A user interface for REMM is being developed in cooperation with USDA-NRCS and California State University.

Previous studies showed little impact of harvesting of riparian forest (Zone 2, not immediately adjacent to the stream). Larger scale studies on harvest impacts are underway at the same site.

Results:

Testing of REMM shows the model to be very sensitive to rotting depth of vegetation, maximum denitrification rates, and other ecosystem properties which can be determined in field studies.

REMM is being tested by researchers studying riparian ecosystems in diverse environment of the U.S. and Europe. Monitoring of two streams draining of field is underway in preparation for a larger scale riparian forest harvest experiment.