388 Forestry Quarterly. 



for removal, since they attack trees weakened in the struggle, or 

 old trees whose vitality is ebbing. 



Table I. — Yield or Longleaf Pine in Pure, Even-aged Stands. 

 Doyle Rule. 



Tyler County, Texas. 

 Age, Yield per Acre, 



Years. Board Feet. 



100, 8,600 



1 10, 9.50O 



120, 10,300 



130, 11,000 



140, 11 ,600 



150, 12,200 



160, 12,800 



170, 13,500 



180, 14,000 



190, 14,400 



200, 14,800 



210, 15,100 



220, 15,400 



230, 15,600 



240, 15,800 



250, 16,000 



260, 15,900 



270, 15,700 



280, 15,400 



290, 1 5,000 



300, 14,350 



310, 13,000 



320, 12,400 



Treatment in Cutting. 



If a cutting is made with the intention of leaving a thrifty 

 growing stand, this process of waste and overcrowding will be 

 checked provided each acre is treated separately. Trees are de- 

 pendent on their immediate surroundings, and the thinning made 

 on one acre will not benefit the trees on an adjoining acre. But 

 properly made, a heavy cutting will put the whole forest into 

 shape so that for the next twenty years the largest possible growth 

 will be obtained, with practically no loss. 



This means the removal of: 



1. All trees affected by red rot or otherwise injured. 



2. Trees with burns or cat faces at the base. 



3. Stunted or suppressed trees, no matter what size. 



These trees are either not increasing at all in value or are liable 

 to complete destruction before the second cut, and their presence 

 prevents other trees from making rapid growth. 



