Study Shows Need for Site-Specific
Riparian Grazing Guidelines

by Carol Flaherty

BOZEMAN -- Montana streams may be as different from Kentucky creeks as a Montana twang is from a Kentucky drawl.

For that matter, different places along the same Montana stream are so different that it calls into question nation-wide grazing guidelines for such areas, say researchers.

That is the conclusion reached after a five-year study of a grazing allotment in the Beaverhead National Forest southeast of Dillon, Montana, says Clay Marlow, Montana State University range researcher. In the studies, livestock grazed some areas according to federal guidelines. In other areas, big game but not livestock grazed, and in one area neither livestock nor big game could graze, though small animals had access.

Stream channel responses to land management in the study areas were site-specific, says Marlow. Some grazed and ungrazed stream channels were no different after five years while a site grazed by both big game and cattle "improved," if improved is defined as the channel becoming narrower and deeper.

Deep narrow channels are sometimes considered "better," because they are cooler, which is better for fish. Similarly, loss of willow and shrubs is considered undesirable because they shade and maintain lower stream temperature. Over-grazing sometimes is indicated by stream channels becoming wider and shallower due to the impact of wildlife and livestock hooves.

Marlow coordinated the studies done by graduate students Mark Manukien and B.J. Rhodes on stream channels in mountain valleys dominated by mountain big sagebrush, wheatgrass and fescue grass. Manukien is now an MSU Extension agent in Prairie County. The areas right along the creeks--termed "riparian" areas--also have willow, sedges and Kentucky bluegrass.

One site was on Long Creek and it is there that one of the grazed stations deepened more than the site that kept out both cattle and big game. The other four Long Creek locations measured were all similar whether they were grazed or not. However, at the site on nearby Pole Creek, all four measured areas were significantly different from each other, with a grazed station showing more deepening than the area where cattle were kept out. All sites showed some deepening and narrowing every year measured.

"Because of the high variability along each stream, we really can't attribute any of the changes in the two pastures to either the livestock or to the grazing management," says Marlow.

"Current grazing guidelines for riparian areas do not have a substantial scientific basis," says Marlow. "Consequently, the grazing permittee, which was the Matador Cattle Company, and the Sheridan Ranger District of the Beaverhead National Forest, joined with the Montana Agricultural Experiment Station to learn how real streams respond to real grazing."

Use of the same grazing standards over large areas cannot be considered a reliable basis for monitoring efforts, because of the natural variation in streams even in the same watershed, says Marlow.

"The use of forest-wide or national standards may not benefit either the natural resource base or local economic uses," says Marlow, adding that this is why collaboration among the various agencies and users is important for long-term protection of the resources and maintenance of local rural economies.

Go to full report of this study.

Send questions or comments and your name, city/state/country and the name of the topic you read to Carol Flaherty, MSU Communications Services, Bozeman, MT 59717, or email Marlow and Flaherty.

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