when the minimum cutting limit is about 16 inches d. b. h. 

 About two-fifths of the loblolly pine and one-fourth of the 

 shortleaf pine volume is in trees at least this size. For 

 hardwoods the minimum limit is generally, higher but 

 varies by species, age of timber, and kind ot product. 

 Two-fifths of the hardwood volume is in trees 19 inches 

 d. b. h. and larger (table 14). 



Table 14. — Distribution of the net board-foot volume (International x %-inch 

 rule) by species group and tree-diameter class, 1938 ' 



Species uroup 



10-12 14-18 20-24 26+ 

 inches ' inches inches I inches 



Softwoods: 



Loblolly pine _ 

 Shortleaf pine. 



Pond pine 



Longleaf pine. 

 Virginia pine . 



White pine 



Hemlock 



Red spruce 



Red cedar 



White-cedar 

 Cypress 



All softwoods . 



Hardwoods 



Sweet gum 



Black and water tupelo. 



Yellow poplar .. 



Red oaks 



White oaks 



Chestnut 



Other hardwoods 



All hardwoods. 

 Ml species 



Percent 

 38.6 

 58.8 

 51.4 

 40.9 

 69.6 

 28.3 

 7.4 

 34.8 

 61.5 

 49.8 

 25.4 



Percent 

 44.5 

 34.4 

 43.5 

 44.8 

 29.5 

 37.3 

 21.2 

 51.3 

 28.9 

 42.9 

 36.8 



62.7 

 59.0 

 62.5 

 54.0 

 52.1 

 29.7 



57.9 



( 3 ) 



65.9 



Percent Percent 



13.5 



6.1 

 4.2 

 12.9 

 .9 

 21.6 

 21.3 

 13.9 

 9.6 

 4.7 

 22.6 



3.4 



.9 

 1.4 

 (') 

 12.8 

 50.1 

 ( 2 > 

 (') 

 2.6 

 15.2 



3.6 



24.9 

 29.9 

 25.7 

 30.2 

 27.4 

 34.0 

 22.6 



27.2 



12.4 



11.1 

 11.8 

 15.8 

 20.5 

 36.3 

 10.6 



14.9 



23.5 



10.6 



i For similar distribution by physiographic divisions, see table 39. appendix. 

 ! Negligible. 



3 The volume of softwoods in the 10-12-inch class is not included in the 

 volume from which all-species percents are derived. 



The distribution of the softwood volume by tree-diame- 

 ter class is more favorable for profitable sawmilling in the 

 Coastal Plain than in the piedmont (fig. 28), as shown by 

 the 40 percent of the volume in 10-1 2-inch diameter class 

 in contrast with nearly 60 percent in the piedmont. In the 

 mountain region the larger percentage of softwood volume 

 in trees 25 inches d. b. h. and over is mostly hemlock, gen- 

 erally considered a poor species. 



In the mountain region an even higher proportion ot 

 hardwood volume is in the larger diameters. Again a 

 single species has a strong influence, for over one-third ot 

 the volume in trees 26 inches d. b. h. and larger is dead 

 chestnut. In the piedmont a large part of the hardwood 

 volume is in small trees because most ot the largest, best- 

 quality timber has been cut, and the second-growth oak and 

 sweetgum is still relatively immature. Here the oaks grow 



slowly and many trees are 80 to 100 years old before thev 

 reach minimum saw-timber size. 



It seems inconsistent to find such a large part of the 

 hardwood volume in trees smaller than 20 inches d. b. h. in 

 the Coastal Plain, where, according to figure 27, 60 percent 

 of the volume is in old-growth stands. One explanation 

 is that two-thirds of the volume in the smallest diameter 

 group is sweetgum and black and water tupelo. These 

 species have reproduced prolifically in the partly cut old- 

 growth stands of swamp hardwoods, and small second- 

 growth trees torm an important part of the stand volume. 

 Another reason is that many pure stands of old-growth 

 black and water tupelos are densely stocked with tall trees 

 of medium diameter. 



/ olumes Per Acre 



Volume per acre is the primary standard for judging a 

 logging chance. Size, age, quality, and location of the 

 timber are taken into consideration, but there must be 

 enough saw timber per acre to support the operation. The 

 minimum varies with the type ot operation, the terrain, 

 and the kind of timber. Stationary mills supplied by 

 logging railroads must operate in heavy stands of extensive 

 acreage in order to repay the large investment in railroad 

 and logging equipment. As a rule the second-growth 

 stands of North Carolina are too light and too scattered 

 for railroad logging. The development of portable saw- 

 mills, efficient motortrucks, and a network of improved 

 highways has altered former concepts ot an operable timber 

 stand. For truck logging to a stationary mill, a stand of 

 2,000 board feet per acre is considered a fair logging chance. 

 Operators ot portable sawmills, however, will set up tor as 

 little as 300 feet per acre if the timber is within a quarter of 

 a mile of the mill. 



Judging by these standards, most of the board-foot 

 volume in the sawlog-size conditions can be profitably 

 cut. More than two-thirds of the land is stocked 2,000 



Figure 28. — Distribution of board-foot volume by diameter class, 1938 



3i 



