Plant stems absorb the erosive force of flowing water and wave action, while roots hold soil in place. Plant stems slow and disperse flow of surface runoff, and promote settling of sediment.
Roots stabilize the trapped sediment and hold riparian soil in place.
Generally less effective for clayey sediments. Periodic removal of sediment from the buffer may be needed to sustain this benefit where sediment loads are high. Uptake and transformation of soluble contaminants by plants and soil microbes is promoted by improved infiltration of surface runoff and vigorous growth of vegetation. Soluble contaminants may be similarly removed from shallow groundwater. No fertilizers, pesticides, or animal wastes are applied to the buffer zone which could be picked up by runoff.