













; 

since 1936 has been accompanied by a 24-percent 
decrease in basal area. While both basal area and volume 
of saw-timber and pole-timber hardwoods declined, 
volume decreased more than basal area in both classes. 
In all other classes of timber throughout the State, 
basal area increased in spite of decreases in volume. 
Even where volume increased, as in the case of pole 
timber, basal area increased even more. 
Stand Quality Declines . 
The decline in volume since 1936 in the face of an 
increase in basal area indicates a general downgrading 
of the stands. As the best stands are cut and the best 
trees in the stands are removed, the trend is toward a 
higher proportion of shorter trees of poorer form. 
Further, the proportion of defect per tree, notably 
among the hardwoods, 
trees are removed. 
The result of this decline in stand quality means a 
lower average net volume per tree. In 1936, the average 
volume per saw-timber tree was 123 board feet; in 
1947, it was 105, a 15-percent decrease (table 9). This 
reduction in volume is only partially explained by a 
shift to smaller-diameter timber. The slight decrease in 
average size of the timber since 1936 can account for 
but a small part of the total change. Most of the 
change represents shorter boles, poorer and 
more defect. 
Not only has the quality of the sound trees decreased, 
but the proportion of cull material in the stands has 
increased. Cull tree volume, mainly hardwoods, now 
makes up 18 percent of the total volume, compared to 
11 percent in 1936. 
increases as the better-quality 
form, 
Slight Decrease in Diameter of Timber 
Apparently, the shift from old-growth timber to small 
second growth was largely completed before 1936. In 
spite of the extremely heavy wartime drain on saw 
timber, the average diameter of saw timber dropped 
only three-tenths of an inch (fig. 36). Only in the 
largest diameter classes has the number of trees decreased 
(fig. 37). These reductions in the number of large trees, 
while sizable in terms of percent, actually do not affect 
the average diameter of the timber very much. Only 
about 6 percent of the total number of saw-timber trees 
are over 19 inches in diameter. The proportionately 
greater increases in number of small trees was the 
principal reason for the slight reduction in the average 
diameter of the timber. 
Hardwoods Increasing 
The relatively large increase in hardwood types since 
1936 has been paralleled by only a small increase in 
the proportion of hardwood basal area (fig. 38). What 
has happened is that the removal of a relatively small 
number of pines served to convert large areas of pine 
type to hardwood. For instance, the removal of the few 
scattered overstory pines in the Sandhills served to 
SPECIES GROUP 
SIZE CLASS AVERAGE DIAMETER AT BREAST HEIGHT 
AND YEAR 
















































SOFTWOODS 
9 INCHES + 
WLLL PEEEEEEEQH0-. 
33’ YWYYYywyxu_cuUUv>™_” 
| INCH + 
1957 CF 
1936 WY Mla 
HARDWOODS 
9 INCHES + 
1947 OUffu7>oao_—>"_u2——o)pJpoHG 
1936 WWI Oo 
| INCH+ 
19467 ffIff7 
1936 eee 





8 
INCHES 
FIGURE 36.— Change in average tree diameter by spectes and 
size of timber, 1936 to 1947. 
TABLE 9.— Change in the average net board-foot volume per tree, by size class and species group, 1936 to 1947 












Softwoods Hardwoods! All species 
Diameter class = 
(inches) 1936 1947 Change 1936 1947 Change 1936 1947 Change 
Bad. ft. Bad. ft Percent Bd. ft Bad. ft. Percent Bad. ft. Bd. ft. Percent 
60 55 -9 57 Si/ie| ere 60 56 —7 
176 159 -—9 121 122 + 1 149 140 — 6 
446 403 —10 315 261 —17 | 373 315 —16 
UO7Fs SCGRBS 5 bone Don Be a aCe 1,019 863 —15 731 537 —27 833 651 —22 
Alisizesioavyapys sote ccna pois 117 98 —16 135 117 --13 123 105 —15 
1 Does not include 10-inch diameter-class trees. 
re ysher Supply Outlook in South Carolina 29 
