Some Pu'iiKim nt Sample Plot Studies 125 



A temporary sample plot containing five acres was se- 

 lected on adjoining private land which had been cut over at 

 the same time that the timber ion the Government sale was cut. 

 All merchantable Jeffrey Pine above twenty inches in diame- 

 ter breast-high and all merchantable White Fir above thirty 

 inches was removed when this area was logged. Privately 

 logged-over areas contain about 1,500 board feet per acre, and 

 have about the following composition: 



Jeffrey Pine 65 per cent 



White Fir 34 per cent 



Other species 1 per cent 



The following data was collected from the two plots for 

 use in the study of the comparative financial returns to be der- 

 rived from clear cutting, as is the case on most private lands, 

 and from cutting for an anticipated second crop, which is 

 one of the objects of the Forest Service in the management 'of 

 the forests owned by the Federal Government: 



1. All trees left on the permanent plot wfyich would 

 have been utilized in a private logging operation were 

 scaled. 



2. All material left on the plot on the privately- 

 logged area which would have been utilized if the logging 

 had been supervised by Forest Officers were scaled. 



3. All material was scaled on the plot on Govern- 

 ment land which could have been removed but was not. 



4. About one hundred stump analyses of Jeffrey 

 Pine and White Fir were made, from which tables were 

 to be constructed showing the time required for a tree 

 to grow from one D. B. H. class to the next. From these 

 tables the rate of growth of the stand in board feet thirty 

 years from now on the plot on the Government land can 

 be computed. 



5. About fifty seedling analyses were made which 

 were used to determine the length of time it takes a seed- 

 ling to grow to stump height. This age must be added to 

 the age of the stump found by analysis. The data obtained 

 in this study was averaged by a curve relating to total 

 age. The following table showing the age of seedlings 

 of various heights was read from this curve : 



