Livestock and Streams The Effects of Grazing Management on Riparian Areas

The Environmental Protection Agency states that agriculture has a greater impact on stream and river contamination than any other nonpoint source. Grazing, particularly improper grazing of riparian areas may con-tribute to nonpoint source pollution. This series of fact sheets looks at the issues of livestock and streams and what livestock producers can do to protect this precious resource. In any discussion about managing grazing livestock to decrease nonpoint pollution, it would be helpful to review what is known about the management of grazing in riparian areas. Although the original grazers were bison, moose, and deer rather than cattle, horses, sheep, and goats; most na-Photo courtesy of USDA Natural Resources Conservation Service. Rotationally grazing cattle on a well-managed pasture is a good best management practice compared to continuous grazing. tive riparian plants species re-grow following a period of grazing (Mosley, et al. 1998; Ohmart, 1996). When farmers displaced these occasional roaming grazers with continuously grazing livestock, riparian areas suffered. Provided with limited grazing areas and little stimulus to move from one area to another, continuously grazing livestock trample streambanks, congregate in the shade and cool breezes next to streams, and overgraze the lush vegetation in these fertile areas (Bellows, 2003). One cannot discuss the effects of livestock grazing on streams without recognizing the interwoven and connected nature of watersheds, riparian zones, streams, and water-shed activities. Activities affecting watersheds or riparian zones also affect stream ecosystems directly, indirectly, and cumulatively. Although this series of fact sheets pri-marily focuses on the riparian areas, it is understated that mismanagement of the land resources in the watershed can have as big an impact on surface water