SHORTLEAF PINE IN VIRGINIA. 



41 



TABLE 20. 



Cost of producing shortleaf pine stum-page in plantations with six per cent 

 gross interest on investment. 



* On account of the small amount of the thinnings and the short period during which tha 

 money from them would be invested only 4 per cent, net is allowed on them. 



In neither of the foregoing calculations is any allowance made 

 for superintendence, and possible losses from insects, sleet and 

 snow breakage, and windstorm damage, but it must also be re- 

 membered that the constant increase in the price of timber is like- 

 wise neglected. 



THjE PROTECTION OF STANDS 



The two important dangers to pine stands, fire and insects. 

 are in a measure interrelated. Those trees which have been weak- 

 ened or injured by fires invite insects, while stands which are lit- 

 tered by the wood which has died from insect depredations, and 

 which have become grassy on account of openings made in the 

 crown cover where trees have been killed by insects are particularly 

 exposed to serious damage from fire. With both dangers, pre- 

 vention is the most effective means of control. 



Fires. While the danger of fire is always present, it is far 

 more serious in connection with young stands and particularly 

 those in process of stocking, such as fields which have recently 

 been turned out, or newly cut or lumbered land. Fires injure 

 such young stands at any season of the year in which they may 

 occur. Although many individuals of shortleaf pine between one 

 and two feet high, when killed by an early spring fire, will sprout., 

 the sprouting capacity is irregular and unreliable (Plate VI, fig. 2). 

 Moreover, most of such sprouts die in a few years, while many of 

 the survivors are forked. After the tenth year, the heavy shade of 



