Table 4 . --Man-hours of work per acre and number of shrubs topped 

 per man-hour on three study areas, 1966 



Study area 



Topping method 



Lopping shears 



Chain saws^ 



Cutting time 



Total time 



MAN-HOURS PER ACRE 



Boise 5.5 1.3 2.4 



Sawtooth 6.4 1.6 3.9 



Modoc 9.5 3.1 5.6 



SHRUBS PER MAN-HOUR 



Boise 30 112 61 



Sawtooth 36 133 55 



Modoc 50 201 109 



^Total time includes time required for saw maintenance and for 

 somewhat more frequent rest periods than when shears were used. 



Effects on Shrub Condition 



Four and one-half years after the topping treatment none of the sample shrubs were 

 dead, and no obvious shrub mortality had occurred in the treated stands. Estimates 

 of the percent of dead canopy indicated no appreciable differences between topped and 

 control shrubs (table 5) . 



Table S.--Mean percent dead canopy'^ of topped and control 

 bitterbrush shrubs before topping and four 

 growing seasons later 



Study area 



: Topped 



shrubs : 



Control 



shrubs 



: March : 

 : 1966 : 



October : 

 1969 : 



March : 

 1966 : 



October 

 1969 



Boise 



6.0 



13.0 



10.0 



10.5 



Sawtooth 



8.0 



18.0 



3.5 



24.0 



Modoc 



10.0 



20.0 



10.0 



25.0 



■^Based on estimated percent dead canopy of 10 topped and 

 10 control shrubs at each location. 



7 



