Introduction 



Interpreting results from clipping studies on range plants 

 is frequently confounded by the conditions under which the 

 plants are clipped. Such studies are usually conducted in one 

 of three ways: (1) clipping selected plants in situ without 

 disturbing the surrounding vegetation; (2) clipping entire 

 plots of vegetation and observing the reaction of selected 

 species; and (3) clipping plants grown in pots without com- 

 peting vegetation. Each approach imposes different stresses 

 on the treated plants in addition to that of clipping. Obvious- 

 ly, clipping an individual plant without disturbing the sur- 

 rounding vegetation subjects the weakened plant to much 

 greater competition for moisture and nutrients than does 

 clipping both the plant and the surrounding vegetation. Mois- 

 ture and nutrient limitations to pot-grown plants would, of 

 course, depend primarily upon the watering regimen and the 

 amount and fertility of soil within the pot. 



Different clipping studies^ reported for the same species 

 often yield conflicting results. In many cases, these differ- 

 ences in plant response can be attributed to competition dif- 

 ferences. For example, Hormay and Talbot^ found that clip- 

 ping Idaho fescue (Festuca idahoensis Elmer) to 1.5-inch 

 stubble height during the flowering stage of growth reduced 

 flower stalk production the following year by 95 percent and 

 basal area by more than 85 percent. Apparently, the Idaho 

 fescue was clipped as individual plants in unaltered surround- 

 ing vegetation. On the other hand, Mueggler^ reported that 



^Hormay, A. L., andM. W. Talbot. Rest-rotation grazing . . . a new 

 management system for perennial hunchgrass ranges. U.S.D.A. Forest 

 Serv. Prod. Res. Rep. 51, 43 pp. 1961. 



^Mueggler, W. F. Response of mountain grassland vegetation to 

 clipping in southwestern Montana. Ecology 48(6): 942-949. 1967. 



1 



