106 FARM FORESTRY 



trees and seldom results in a revenue to the owner, owing to 

 the small size of the material removed. The work of cleaning 

 can be carried on in the winter time. It will repay the owner, 

 in that the trees will grow faster and the poorer kinds of 

 trees will be removed, assuring a stand of desirable trees in 



the future. 



In making a cleaning only sufficient material should be re- 

 moved to accomplish the purpose desired. Sometimes a tree 

 overtopping a better tree can be broken off or bent to the 

 ground so that it will no longer injure the tree beneath. Some- 

 times the cutting of a single branch will release to the light 

 the tree being shaded. Only material should be removed that 

 is necessary, so that the cleaning should be made rapidly and 

 at little expense. 



Pruning. Pruning is the cutting of lower dead or living 

 branches from trees. The objects of pruning are to improve 

 the form of trees, to concentrate the growth in a single leader, 

 and to secure trunks clear of limbs, so that lumber free from 

 knots will be grown. Pruning would not be a practical opera- 

 tion over a large forest, but in a small farm woodlot or forest 

 planting it can often be done with great advantage to the trees 

 and profit to the owner. Pruning takes place naturally in the 

 woodlot where trees stand closely together. Young saplings 

 are often seen with long, clear boles, free of branches for many 

 feet. With intolerant trees this natural pruning takes place 

 rapidly. With tolerant trees the lower branches will remain 

 alive many years and will remain on the tree many years 

 after they have died. 



In pruning limbs they should be cut off smoothly and as 

 close to the trunk as possible without tearing the bark. With 

 large limbs it is best to make an undercut first, so that the 

 limb in falling will not tear the bark of the tree. Limbs that 

 are dead and the wood brittle can be knocked off. The trunks 

 of the most vigorous trees in the woodlot should be pruned 

 of branches for from 16 to 20 feet, so that at least one good 



