| David L. Turner and Warren P. Clary |
| Authors are statistician, Rocky Mountain Research Station, Forestry Sciences Laboratory, 860 North 1200 East, Logan, Ut 84321 and supervisory range scientist, Rocky Mountain Station, Forestry Sciences Laboratory, 316 E. Myrtle Street, Boise, Ida 83702. |
Abstract |
| Stubble height, a measure of the amount of vegetation remaining after grazing, is thought to be a useful variable in the management of riparian areas. A number of riparian and grazing processes appear to be directly or indirectly affected by the residual stubble height. Thus, average stubble height is often used to evaluate the livestock impact a pasture has received, particularly in riparian zones. Stubble height sampling methodology has received little previous attention. A sequential sampling procedure for stubble height was investigated. The procedure provides statistically defensible answers in the shortest possible amount of time. The procedure does not require a rigid sample size and involves simple yes/no answers at each observation. A small initial sample of readings is selected and evaluated. If there is sufficient information to make a clear decision, then grazing is either continued or stopped. If the initial evidence does not clearly support either decision, then sampling proceeds. This may continue for several iterations before a decision is reached. Statistically supportable decisions can typically be made within a short time frame using this method. This method may also be applied to evaluate trampling and other yes/no responses. |
| Key Words: grazing management, riparian areas |