Table 5. — Net board-foot (International \i-inch rule) and cordwood volume per acre of the shortleaf -loblolly -hardwood group, classified according 



to species group and forest condition 



Forest condition 



Shortleaf-loblolly pines 



Pulping hardwoods 



Nonpulping hardwoods 



All species groups 



Old growth: 



Uncut 



Partly cut 



Second growth: 

 Savvlog size: 



Uncut 



Partly cut 



Under sawlog size. _ 



Reproduction 



Clear-cut 



Weighted average 



Board feet 

 8,160 

 3,660 



3,830 



2,250 



300 



120 



Cords 

 20.4 

 10.3 



13.6 



9.1 



2.8 



.4 



.3 



Board feet 

 740 

 580 



280 

 210 

 30 



._,.,( i 



Cords 

 3.9 

 2.7 



1.7 

 1.4 



.5 

 .1 



Board feet 



1,140 



850 



440 



3(10 



Cords 

 5. 1 

 3.9 



2 7 



2.4 



1.0 



.1 



.1 



Board 

 10. 

 5 



feet 

 040 

 090 



,550 



,820 



390 



140 



100 



3. 2110 



Cords 

 29.4 

 16.9 



18.0 

 12.9 

 4.3 



.4 



13.5 



i Includes a negligible quantity of longleaf. 



Age 



The old-growth timber stands are characterized 

 by trees varying in age from 70 to over 150 years. 

 The typical trees in sawlog-size second-growth 

 pine stands are 30 to 70 years old (average about 

 45). Hardwood stands of the same condition 

 are somewhat older, averaging about 70 years of 

 age. Second-growth stands under sawlog size of 

 both pine and hardwood are characterized by 

 trees 10 to 50 years old, but most of these stands 

 are 20 to 30 years. Most of the trees of both pine 

 and hardwood in the reproduction condition are 

 less than 10 years old. 



Site 



Differences in the productive capacity of forest 

 land are dependent upon many factors, such as 

 topography, soil, moisture, and drainage. The 

 term "site" is used to include the combination of 

 these many factors and is a valuable measure of 

 possible productivity. In pines, the site index is 

 the height of the average dominant trees at 50 

 years of age. A site on which dominant trees of 

 the prevailing species grow 80 feet or more the 

 first 50 years will produce the maximum volume 

 per acre in tall, well-formed trees in a shorter 

 time than poorer sites with a lower site index. 

 Figure 6 compares the approximate percentage of 

 site classes in each of the three pure pine types. 

 The sites are designated as "50 feet and less," 

 "60 and 70 feet," and "80 feet and over." 



The hardwood area was segregated into three 



broad site classes (good, fair, and poor), based 

 upon height, form, and general thriftiness of the 

 trees. In figure 7, giving the percentage of the 

 sites in each hardwood type, the cypress-tupelo 

 type with 96 percent of its area in fair or good 



AREA 

 (PERCENT) 



■I 





J 



n 



SHORTLEAF PINE 



LONGLEAF PINE 



50 FEET 

 AND LESS 



Figure 6. — Percent of area in pine types in three site classes 



sites, is in marked contrast to the scrub-hardwood 

 type with 98 percent of its area in poor sites. 

 These two types illustrate the difference in site 

 quality that obtains on two entirely distinct 

 topographic situations; the cypress-tupelo type 

 occurs in the deep, fertile soil of the river bottoms, 

 while the scrub hardwoods are found on the 

 dry, sterile soil of the rolling uplands. 



13 



