CARING FOR THE GROWING WOODLOT 109 



ning will start to grow faster as soon as the crowns are liber- 

 ated. It will not be many years, owing to the spreading of 

 the crowns of these trees sidewise, before their crowns will 

 come together again and the crown canopy will be intact. The 

 trees will have grown considerably in height when this takes 

 place and this canopy will be many feet highsr above the forest 

 floor than it formerly was. As soon as the crowns touch the 

 struggle starts over again between the trees. The time when 

 this new struggle begins after the first thinning will vary with 

 the kind of tree and the severity of the first thinning. In 

 general in about ten years after the first thinning another 

 struggle will have started. This older stand will live over 

 again the life of the younger stand. The more severe the fight 

 the slower will the trees grow. Soon some trees will begin 

 to forge ahead and others to drop behind. The tree crowns 

 again become separated into dominant, intermediate and sup- 

 pressed trees. If the struggle is allowed to go on the trees 

 will practically cease to grow, the energy being used up in 

 the struggle for existence. It is time another thinning was 

 made. The trees that have fallen behind and whose crowns 

 have been overtopped should be removed to give the better- 

 formed and taller trees more room to expand. Care must be 

 taken, as before, not to remove too many trees so as to break 

 the crown canopy too much. The struggle must continue for 

 the production of clean boles. Owing to the large size of the 

 trees when this second thinning is made the trees cut out can 

 be worked up into cordwood. A cleaning and the first thin- 

 ning rarely pay for themselves, as the material obtained is 

 small. They are made for the benefit of the growing timber. 

 The second and subsequent thinnings should pay for the time 

 and labor needed to make them in the cordwood obtained. 



Throughout the life of the growing stand every ten or 

 fifteen years similar thinnings should be made. By relieving 

 the stand of the necessity of killing out the trees that fall 

 behind and by giving each tree the room it needs for its best 



