The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council. |
Wednesday, January 30, 2008
51
Impacts of Cattle Trampling on Streambank Integrity
Stephanie A. Sever, Jeffrey C. Mosley, and Tracy K. Brewer. Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717
Streambank trampling by livestock potentially can degrade riparian ecosystems. Resource managers, particularly on public lands in the West, have responded by implementing streambank-trampling guidelines for managing riparian livestock grazing, and streambank trampling measurements are often the trigger that initiates moving livestock to a new unit or moving them off a grazing allotment. However, no research studies have quantified the threshold levels of streambank trampling that degrade streambank integrity. Our study evaluated the effects of 3 different cattle trampling intensities (none, moderate, heavy) along one foothill rangeland stream in west-central Montana . Cattle trampling treatments (3 replicates per treatment) were applied in late summer-early fall of 2005 and 2006. Pre-treatment streambank measurements were made in late summer-early fall of 2005, and streambank response was measured in late summer-early fall of 2006 and 2007. Streambank response variables included bank cover, bank stability, bank height, bank angle, and bank undercut. Preliminary results indicate that heavy trampling (mean=47% streambank disturbance) degraded 4 of the 5 streambank variables compared with the control (i.e., no cattle trampling), whereas moderate cattle trampling (mean=23% streambank disturbance) degraded 2 of 5 streambank variables.