LOBLOLLY OR NORTH CAROLINA PINE. 49 



SLEET AND SNOW. 



The leaders of loblolly pine are sometimes broken by sleet or wet 

 sii<.\\. particularly in the northeastern counties. On shallow soils the 



:ire in exceptional cases overturned by the weight of wet snow. 



\VIMi-l IK MX ESS. 



On <lerp in. How soils in which the roots descend to a depth of three 

 feet ur in. . tin- loblolly pine is compurat ivcly wind-firm. On dry and 

 shallow soils the roots are not so deeply seated or so firm, and the trees 

 are more subject to windfall. The danger is greatest on heavy upland 

 clays and on shallow sandy soils underlaid by hardpan. In the old 

 fields on the red clays many of the roots often fail to penetrate below 

 the layers loosened in plowing. Staml< on such sites, if at all exposed, 

 an- particularly liable to suffer severely after a heavy thinning or after 

 culling. The numlxT of windfalls, three years after lumbering on 110 

 acres of cut-over land having a dry, compact clay soil amounted to 100 

 trees, 8 inches and over in diameter, or alxmt 4..~> per cent of the tree? 

 left. On the deep sandy soils, the loss from windfall after lumbering is 

 negligible. 



THE >VOOD AMI ITS USES. 



QUALITIES. 



The wood of the loblolly or North Carolina pine is heavy, hard, 

 strong, coarse grained, and decays rapidly in contact with the soil. It 

 shrinks and checks considerably in drying. In kiln drying the shrink- 

 age amounts to about 10 per cent of cross section (not length). From 

 3 to 4 per cent of the shrinkage is radial and 6 to 7 per cent is around 

 the circumference. In air drying the shrinkage is less.* The shrink- 

 age is greatest in the heavy sapwood from the base of young trees and 

 least in the lighter heartwood from the tops of old trees. The wood, 

 like that of all pine, swells again after commercial kiln-drying whenever 

 exposed to dampness. The heartwood is yellowish to orange brown in 

 'color; the thick sapwood much paler. The soft spring wood in each 

 annual layer is nearly white, while the very hard and tough summer 

 band is dark brown, the contrast in color and hardness between these 

 two layers being greatest near the stump and in the center of the log in 

 young, thrifty trees which have formed no heartwood. Although the 

 wood from the upper part of the stem is coarse grained, the summer 

 band is very narrow. (Plate X, A.) Because of the great differ- 

 ence in density between the spring and summer wood coarse-grained 

 boards, when plane.d, do not readily dress to a perfectly flat surface. 

 On the other hand there is great adhesion between the two layers which 

 reduces the tendency to split and sliver, so common in many coniferous 

 woods. 



Bui. 99. U. S. Forest Service. 

 4 



