Ecological Implications

The USDA Forest service (Welsch, 1991) issues the official definition of a riparian buffer zone as: “the aquatic ecosystems and the portions of the terrestrial ecosystem that directly affect or are affected by the aquatic environment” (Mitsch, 1999). These buffer zones function in various ways. Their colonizing plants stabilize banks and shorelines, provide habitat for both aquatic and terrestrial species, and of course, function as sinks, protecting aquatic ecosystems from the types of nonpoint source pollution we address throughout our website.

Mitsch (1999) detailed a series of requirements for riparian buffer zones to maximize nutrient removal. The most important is hydrology, making sure that water moves slowly enough for sediment to fall to the benthos and also making sure that ground water comes into contact with plant roots to enable denitrification. If the water moves too quickly, it will carry almost as many sediment and nutrients out of the system as it did in. Other important attributes of riparian buffers are the width, vegetation amount and zonation. However, these tend to vary according to specific site and requirements.

Riparian buffer zones and wetlands are not always equally efficient. Mitsch (1999) uses the example of a drainage system. Wetland basins are more effective at nutrient removal than riparian buffers when drainage tubes are being utilized. Therefore, while both can be very important to use in non-point source pollution management, whichever one is used depends on the area morphology.