Good trees below sawlog size form 93 percent 

 of the forests of the unit, of which pines account for 

 41 percent and hardwoods 52 percent (fig. 4). 

 Many of these small hardwoods are partially 

 defective or of inferior species; their removal would 

 greatly improve the productive capacity of the 

 forest. Trees 17 inches and larger in diameter, 

 which yield the highest grades of lumber, make up 

 only 1 percent of the total stand. 



In figure 5 the age-class and volume distribution 

 of the present forest in the longleaf- and shortleaf- 



GROSS VOLUME 



PER ACRE (CUBIC FEET 



3,000 1 



61-70 YEARS 



r^JM 



0-10 U - 20 21-30 



YEARS YEARS YEARS 



(8%l 18%) (H%> 



EVAIL1NG ACE CLASSES AND VOLUMES 



E SAME AREA UNDER MANAGEMENT 



Figure 5. — Prevailing age class and volume distribution (7935) 

 compared with those on the same area under management. Gross 

 volume per acre is measured inside bark on trees 5 inches d. b. h. 

 and larger, turpentine butts not included. Under management, 

 each age class occupies 74.3 percent of the total 



loblolly-hardwood types are compared with those 

 on a managed forest of the same general type 

 handled on a rotation of 70 years. The portion 

 of the figure showing the prevailing age classes 

 and volumes represents a rough division of the 

 4,909,400 acres of the present forest in these types 

 into areas characterized by the respective age 



classes. The volume per acre and extent of occur- 

 rence of each age class is based upon the actual 

 stand as it existed at the time of the survey. In 

 the managed forest the area is divided into seven 

 equal areas, each containing one age class. The 

 per-acre volumes are the averages of the best 

 stocked 10 percent of the uncut stands on the 

 weighted average site in each age class of the pres- 

 ent pine and pine-hardwood stand. 



Inspection of this figure reveals several important 

 facts about the present forest. (1) The average 

 stand is understocked, in that its present volume is 

 only 48 percent of that of the managed stand. 

 (2) The distribution of age classes by area closely 

 approximates that of the managed stand, the chief 

 discrepancies being in the two age classes below 

 21 years, which together occupy only about half 

 of the area desirable in a managed forest. (3) 

 The ideal distribution of age classes could be 

 attained theoretically by a gradual cutting of a 

 small percentage of the area in each of the four 

 oldest age classes during the next 10-year period 

 so that the areas in stands below 21 years of age 

 would be increased proportionately. 



Volume per Acre 



Tables giving the average volume per acre do 

 not show the extremes within a particular type 

 and condition but they do indicate the range in 

 volumes of the various conditions in a given type 

 or type group, and in addition they portray the 

 relative abundance of the various species groups. 

 A better conception of the make-up of the forest 

 may be obtained from table 5, which gives average 

 board-foot and cordwood volumes per acre of the 

 shortleaf-loblolly-hardwood group, constituting 

 more than 60 percent of the forested area. The 

 board-foot volume is expressed in the Inter- 

 national %-inch rule and includes only saw- 

 timber material; the cordwood volume is of all 

 sound trees at least 5 inches d. b. h., including 

 the saw-timber material expressed in board feet. 1 



i A more complete and detailed presentation of the 

 average volumes per acre of forest land can be found in 

 Southern Forest Survey Release No. 26, Volumes on an 

 Average Acre in the Various Units of the Pine Hardwood 

 Region West of the Mississippi, issued July 12, 1937. 



12 



