Response of a Southwest Montana Riparian System to Four Grazing Management Alternatives

Abstract.-The effects of deferred rotation, time control (Savory Grazing Method), season-long, and livestock exclusion on streambank stability and trout habitat condition in a southwestern Montana riparian zone has been monitored since 1986. Although livestock exclusion appeared to improve channel conditions in 1986, there was no significant difference among any of the treatments thereafter. The decline in trout habitat condition appeared to be more a function of stream discharge and channel aggradation than grazing management. The lack of significant differences (P< 0.10) in bank stability among the various treatments during three consecutive drought years suggests that it is the interaction between grazing and stream discharge events that dictate the magnitude ofstreambank alteration. Downward shifts in livestock numbers will probably not limit streambank degradation and loss of trout habitat. Decreasing the length of time cattle have access to a stream reach and adjusting the grazing period to coincide with low streambank moisture levels shows promise for the improve ment of riparian zone condition. Wildlife and land managers seldom have to defend the importance of riparian ecosystems since the 1978 Calla way Gardens Symposium (Johnson and McCormick 1978). N ow efforts are directed to finding the most effective ma