31 



might happen that this line between the ranges may be well located 

 for a fire lane and under these conditions would serve for both 

 boundary line and fire protection. 



Each range may again be divided into smaller divisions called 

 blocks. These may or may not be of value other than reducing the 

 area into workable sizes. If it should be convenient to divide the 

 range into blocks by natural boundaries, very good; if not, it may 

 be no detriment to the range. On large ranges this division into 

 blocks may aid in designating any particular part of the range. 



Again blocks are divided into compartments. Compartments are 

 sometimes called the sylvicultural unit because they form the unit 

 of work. The whole of this division is effected by using in addition 

 to the outer boundary lines, interior natural lines, as creeks and 

 smaller water courses; or some geographic unit, as a basin formed 

 by two hills, the entire flat on top of a hill, or, in some cases, from 

 the top of a hill to a ravine. 



The boundaries of compartments may be made to coincide with the 

 conditions of growth. For instance, a compartment may be com- 

 posed of a pure stand of pine, of chestnut, or of some other species. 

 Age conditions and, in some cases, public roads may conveniently 

 form compartment boundaries ; but it is best to have some geographi- 

 cal feature form boundaries when convenient. This will do away with 

 the possibility of the lines ever being changed, something that must 

 be guarded against. 



The size of the compartments as well as of other divisions depends 

 on the intensity of management, the extent of danger from fire, and 

 the size of the former division. 



When there is necessity for dividing compartments these divisions 

 are known as sub-compartments. Such sub-divisions should be 

 avoided as much as possible because of the additional expense in- 

 curred in their management. When a compartment is composed of 

 an area of large trees and an area of small trees each area may be 

 called a sub-compartment, but as soon as there areas can be thrown 

 together without much distinction of age classes it should be worked 

 as one compartment. 



Among the advantages to be gained by dividing the reserves are 

 the following: 



Each ranger knows exactly the area which he is to cover or patrol. 



In case of operations a record can be kept and the exact location 

 designated. 



The best management can be effected by striving toward the ideal 

 forest, and this is most easily accomplished by a systematic division 

 of the forest into workable units. 



