286 



JOURNAIv OF FORESTRY 



that the groups are too dense for maximum volume production. On 

 the other hand, it is quite obvious that the larger openings in virgin 

 as well as in cut-over stands could be more heavily stocked without 

 causing harmful competition. 



Investigations by Weitknecht in eastern Oregon show that the di- 

 ameter accretion in western yellow pine after cutting is considerably 

 greater at breast height than further up the stem, and therefore incre- 

 ment figures based upon breast-high measurements will be too high. 

 This question has not been investigated in the present study, but un- 

 doubtedly it demands consideration. It is believed, however, that the 

 discrepancy between growth at breast height and at other points in the 

 stem will be less in Arizona and New Mexico than in Oregon, be- 

 cause in the former region the bulk of the reserved stand occurs in 

 groups which were practically undisturbed in cutting. 



NATURAL REPRODUCTION 



The seedling record in Table 6 indicates that reproduction is pro- 

 gressing unsatisfactorily. These results are typical of considerable por- 

 tions of the Conconino and Tusayan National Forests. It is a dis- 

 couraging fact that on none of the areas cut by the Forest Service on 

 these two forests has good reproduction taken place since the cutting. 



