An Ecological Study Of The Effects Of Cattle Grazing On Willow (Salix sp.) On Two Riparian Zones Located In The Beaverhead National Forest, Beaverhead County, Montana

Abstract

A comparison was made between two woody riparian trend plots from one Bureau of Land Management (BLM) allotment grazed during the hot season and another BLM allotment grazed during the cool season. Statistic, field, and photographic studies showed that willow (Salix sp.) growth and reproduction was severely damaged by cattle grazing on the allotment used during the hot season. However, on the allotment grazed during the cool season there was a substantial increase in willow growth. Since cattle prefer the cooler and more nutritious riparian zones during the warm summer months, the number of days cattle spent there increases substantially compared to the warmer adjacent uplands. To correct this situation, the length of stay on a pasture grazed during the hot season should be based on the percentage of pasture actually being utilized by cattle during that time period, and not on the pasture as a whole.