Table II . --Aacioriulative mortality on thicket thinning treatments 

 3, 5, and 10 years after thinning"^ ^ 



Thinning 

 treatment 



3 years 



5 years 



10 years 



Light 



Medium 



Heavy 



13 

 17 



17 



26 

 28 



23 



Average 



15 



26 



^Expressed as a percent of the reserve stand. 

 ^The number of years is only approximate because of 

 different measurement schedules. 



Suppressed, poor vigor trees accounted for nearly all of the mortality. Dominant 

 trees of good vigor made up only a small portion of the mortality during the study 

 period, as shown in the following tabulations. 



Crown class 



Mortality 



(Percent of total) 



Dominant 

 Codominant 

 Intermediate 

 Suppressed 



1 



5 



26 

 68 



Total 



100 



Vigor class 



Mortality 



(Percent of total) 



Good 

 Fair 

 Poor 



4 



14 



82 



Total 



100 



Although heavy thinnings produced more Christmas trees in the first 10 years, the 

 possibilities of future production were better on the medium and lightly thinned areas, 

 They still had about three times as many dominant and codominant trees and twice as 

 many trees of good or fair vigor as did the heavily thinned areas (table 12). 





Table 



12. --Crown and xtigor olassifioation of the residual 

 10 years after the original thinnings 



stands 







Thinning 



: Total 

 : residual 

 : stand 





Crown class 





: Vij 



jor class 



treatment 



: Dominant 



: Codominant : Intermediate 



Suppressed 



: Good 



Fair : 



Poor 



Light 



Medium 



Heavy 



7,820 

 5,920 

 4,720 



220 

 240 



60 



------ Trees per aare - 



1,160 2,320 

 920 1,760 

 380 1,420 



4,120 

 3,000 

 2,860 



460 

 600 

 180 



3,140 

 2,200 

 1,240 



4,220 

 3,120 

 3,300 



Average 



6,153 



173 



820 1,833 



3,327 



413 



2,193 



3,547 



13 



