SHORTLEAF PINE: IMPORTANCE AND MANAGEMENT. 7 
pounds, but varies in accordance with the moisture content, which 
ranges from 12 to 18 per cent. Green shortleaf in the log averages 
45.5 pounds per cubic foot, with a moisture content of 31 per cent for 
heart and 88 per cent for sapwood. The loss of weight in drying 
amounts to about 25 per cent for the heartwood and about 60 per cent 
for the sapwood. In passing from a green to an oven-dry condition 
the wood shrinks about 12 per cent in volume, about one-third of 
which occurs in passing from the green to the air-dry (15 per cent) 
condition. ‘The density of absolutely dry wood is variable, its specific 
gravity being from 0.48 to about 0.56.1. This difference in density 
seems largely due to the varying conditions of growth over its wide 
geographic range. 
In resin content shortleaf ranks lower than longleaf pine and 
about the same as loblolly, although all are variable, and the amount 
of difference has not been definitely determined. When the sapwood 
of shortleaf is freshly cut limpid resin oozes out freely. Occasionally 
the heartwood and normally the bases of all large limbs become 
highly impregnated with resin and furnish “ lightwood” and “ pine 
knots,” extensively used for firewood. In fuel value shortleaf aver- 
ages about 12 per cent below longleaf, of which 1 cord is approxi- 
mately equivalent to a ton of coal. This is largely due to the differ- 
ence in the average density of the two woods. For woods of the 
same weight per cord of the two species it is believed there is little 
difference, if any, in heat producing power.’ 
The wood varies somewhat in hardness, and in some regions is 
moderately soft. In its southern range it averages about as hard as 
longleaf pine when there is the same proportion of summer wood 
in the annual rings. The wood grown in the more northern regions 
or at higher altitudes in the southern region seems to be softer. 
The width of the rings is greatest in early life. Ten to twelve 
rings to the inch is an average rate of growth during the middle 
period, say from 60 to 140 years. Within the individual annual 
ring, the transition from the spring to the summer wood is normally 
quite abrupt, giving the annual ring the appearance of two sharply 
defined lines or bands. In young and rapid-growing trees and in 
those growing where the summers are short, the transition is com- 
monly more gradual. 
Since the fibers are straight and do not interlock, the oot 1s 
straight grained, easy to split and but slightly subject to warp and 
check in drying. The wood is easily worked, may be given a good 
finish, and takes paint and wood preservative well. The contrast 
1 Latter figure not definitely determined. 
2 Forest Products Laboratory, Madison, Wis. 
