390 Forestry Quarterly. 



acres square, each of which was tallied by diameters and esti- 

 mated. The object was to leave all the young thrifty timber, 

 take out all overmature, stunted and defective stuff, and leave 

 seed trees. 



The actual results are shown in tabular form, according to the 

 density of the original stand. 



TABLE II. 



Proportion of Merchantable Stand Per Acre of Longleaf Pine 

 Removed By a Selection Cutting. 



Class Average Amount Amount 



Bd. ft. per acre, stand. 



FEET PER acre — Bd. ft. 



Under 5,000 . . . 4,257 



5,000-7,500 6,704 



7,500-10,000 8,679 



Over 10,000 12,029 



Table III shows strikingly the contrast between an intelli- 

 gent selection of trees and an arbitrary rule of cutting. Even in 

 the 12-inch class, corresponding with 14 inches on the stump, 34 

 per cent, is removed because it is unfit to remain. On the other 

 hand, some timber is left standing that is over 20 inches. This 

 is in all cases left as seed trees, but is sound and windfirm and 

 will stand safely till the second cut and make considerable growth. 

 In the 14 to 20 inch classes a diminishing number of trees are 

 left, those taken being the trees that will not make good growth. 

 In these classes the trees which grow the best are also the best 

 seed trees, have well developed crowns and are not too tall. 



The amount of growth to be expected on such stands is influ- 

 enced by three factors : 



1. Number and size of merchantable trees left standing. 



2. Number of trees which will become merchantable before 

 the second cut. 



3. Increased growth due to opening up of the stand. 



The growth was studied on eight typical plots of ten acres 

 each or eighty acres, and the results show what can safely be de- 

 pended on for similar stands. 



A period of twenty years was taken as the time elapsing before 

 the second cut. First, the actual diameter growth of several hun- 

 dred trees was measured for the last twenty years on stumps, 



