56 PRACTICAL FORESTRY IN 



composed of many comparatively small branches, and with 

 rough dark bark showing no flat scaling, are sure to be grow- 

 ing rapidly, even if quite large. They are also less desired 

 by the lumberman, who often calls them black pine or black- 

 jack, so may often be spared, without much sacrifice, for seed 

 trees or in order to continue their rapid wood production. 



The seed tree problem in such a pine forest and under such 

 a system as has been described is comparatively simple, for 

 there are likely to be enough young trees of fruiting age left 

 to fill up the blanks between existing seedlings. The density 

 of the latter determines to a large extent the number and 

 location of seed trees necessary, but there should always be 

 two to four to the acre, even if this requires leaving some that 

 would otherwise be logged. 



Under this system recurring cuts may be made at periods of 

 perhaps 30 or 40 years, taking out each time the trees which 

 have passed the minimum diameter since the last previous 

 cut. It is obvious, however, that if the process is to continue 

 indefinitely, protection must be absolute. Destruction of 

 young growth will stop the rotation at the time the surviving 

 older material is harvested. At each cut the brush should be 

 disposed of with this end in view. If the stand is very thin 

 it may not add much to the danger of fire and, especially if 

 reproduction is difficult and requires shelter, may best be left 

 spread on the ground at some distance from remaining trees. 

 Otherwise, and this is the rule, it should be piled and usually 

 burned. In this process and in logging every effort should be 

 made to protect existing young growth from injury. Ground 

 fires should be prevented now and always hereafter. 



So far, however, we have been considering how to make the 

 most of a stand of many ages, due to constant reproduction 

 permitted by the light supply in a fairly open forest. On the 

 other hand, yellow pine sometimes produces a mature stand 

 so heavy that there is little young growth beneath it, or even 

 a thin old stand with either little reproduction or an invasion 

 of lodge-pole pine. Such conditions arc usually due to fire 

 at some period. In the first of these cases, usually the dense 



