28 WORKING PLAN FOR FOREST LANDS NEAR PINE BLUFF, ARK. 



hardwoods were cut, it is a most fortunate circumstance that even 

 after ordinary lumbering the pine will eventually predominate, for 

 the simple reason that the locality is one naturally suited to it. 



Only those silvicultural operations are allowable which are justified 

 by future returns. In this particular case there is no doubt that the 

 very slight expense caused by leaving an occasional seed tree and main- 

 taining a system of tire protection is well justified by the increase in 

 value which will result to the future stand. Anything beyond this 

 would involve ;i present expense without the certainty of an improve- 

 ment in the forest which would pay for it. 



Occurrence. — In the present composition of the forest the Shortleaf 

 Pine occurs most frequently by single specimens, although found at 

 times in small groups. It is almost invariably associated with the 

 hardwoods, seldom forming pure stands. In the future forest the 

 occurrence of this species should be more and more by groups, and by 

 groups constantly increasing in size. Such will be the case if fire is 

 kept out. 



Development. — Under ordinary forest conditions this species pro- 

 duces a long and straight cylindrical bole, having at times a clear 

 length of nearly 60 feet. The crown is irregular in shape, approach 

 ing the form of a truncated cone, and the stem has a tendency to fork 

 near the top of the crown. The height of merchantable trees varies 

 from 70 to 120 feet. Trees over 40 inches in diameter breasthigh are 

 very rarel} T met with. 



The accompanying diagrams illustrate the growth of the Shortleaf 

 Pine. They are simply graphic presentations of the figures obtained 

 from the stem analyses. 



Relation of diameter to height. — This curve shows the relation 

 between the diameter and the height growth of Shortleaf and Loblolly 

 Pine, since the two species exhibit no marked difference in this respect. 

 As can be seen from the curve, the height increases very rapidly with 

 diameters up to 5 or 6 inches. The rate then diminishes in a very 

 uniform manner until the largest diameters are reached. (See fig. 4.) 



Relation of age to diameter. — The relation between age and diameter 

 breasthigh is here shown for both Shortleaf and Loblolly Pine. 



The diameter of the Shortleaf increases very regularl} 7 for the first 

 hundred years, after which the rate of increase begins gradually to 

 fall off. For the first hundred years the average time required to 

 grow 1 inch in diameter is five and one-half years. It will be seen 

 from the curve that if 12 inches be taken as the cutting limit, Short 

 leaf Pine first becomes merchantable after sixty-two years. (See fig. 5.) 



Relation of age to height. — The height growth for both Shortleaf 

 and Loblolly Pine is represented in this diagram. For Shortleaf the 

 height growth is exceedingly uniform and quite rapid for the first 

 twenty years, after which period the rate gradually diminishes. For 



