Table 2. — The average number of trees killed 

 by gophers on each aspect during 

 the 5-year period after planting 



Aspect 



Trees killed 





No. 



Northwest 



1.22a 1 



Southwest 



0.93ab 



Northeast 



0.36b 



'Values shown are means for 45 experimental 



units, each containing 10 trees. 



Means followed by 



the same letter are not significantly different, a = 



0.01. 





Table 3.— The average number of trees of 



each species killed by gophers 



during the 5-year period after 



planting 





Aspect 



Trees killed 





No. 



Ponderosa pine 



1.20a 1 



Douglas-fir 



0.82ab 



Lodgepole pine 



0.49b 



'Values shown are means for 45 experimental 

 units, each containing 10 trees. Means followed by 

 the same letter are not significantly different, a = 

 0.05. 



NO. OF TREES 



PfMlEHOSA 

 PINE 



NORTHWEST SOUTHEAST NORTHEAST 



Figure 4.— Average number of trees killed by gophers. Bars depict 

 the number killed by gophers per 10-tree plot. Lines depict mean 

 comparison intervals by Gabriel (1978). Treatment means with 

 lines that overlap are not significantly different. 



5 



