Between 1962 and 1970, cropland area increased and the 
area in pine management types on other private owners 
dropped by an average 434,000 acres per year. This 
declined to 356,000 acres per year between 1970 and 1977 
and has fallen further, to 309,000 acres per year since 
1977. The reduction in pine type acreage since 1962 is now 
contributing to lower softwood ingrowth and declining net 
annual growth. 
Since 1977, net pine type losses to landclearing have 
amounted to about 90,000 acres per year. Since clearing for 
cropland or pasture is roughly in balance with reversions 
of cropland to timberland, the net loss of pine type acreage 
is the result of urban and industrial expansion, new rights- 
of-way, new rural residences, and other relatively permanent 
timberland withdrawals. 
Lack of adequate pine regeneration also contributes to 
losses in pine type acreage. Inadequate regeneration follows 
on about half of all other private timberland clearcuts in the 
South Central region, causing an annual loss of 150,000 
acres of pine types. Partial harvests, almost always in- 
volving removal of merchantable softwood from a mixed 
stand, produce a net shift to hardwood type of 60,000 acres 
annually. 
A second factor contributing to the reduction in pine growth 
is an increase in mortality. Based on recent surveys, soft- 
wood mortality has roughly doubled in the South Central 
region in the last 10 years (table 3.17). Pine bark beetles 
and disease, principally fusiform rust, account for two-thirds 
of the mortality loss. Weather, other insects, and suppres- 
sion also account for a significant proportion of growth loss. 
Mortality now causes losses equal to 15 percent of gross 
growth, or an annual volume loss of 415 million cubic feet 
for all owners, including 246 million cubic feet for other 
private owners. Since 1976, net annual growth of softwoods 
on other private timberland has declined by 174 million 
cubic feet while annual mortality increased by 125 million 
cubic feet. Mortality has been responsible for more than 70 
percent of the change in net softwood growth on other 
private timberland since 1976. 
A third factor related to mortality is cull increment, an 
increase in the number of growing stock trees becoming 
rough or rotten and unusable for industrial wood products. 
Losses in cull trees used to be insignificant, but they now 
amount to roughly 16 percent of mortality. This is an addi- 
tional loss of 65 million cubic feet annually for all owners. 
Causes of cull increment are similar to causes of mortality. 
Both mortality and cull increment are expected to increase 
further as the average age and stocking of South Central 
softwood stands increase. 
A fourth contributing factor may be changes in stocking 
levels, which reflect management intensity. Recent surveys 
have highlighted an increase in both overstocked and under- 
stocked stands, neither of which is likely to grow at optimum 
rates. In Alabama, the area of understocked timberland 
(timberland less than 60 percent stocked with growing stock 
trees) increased from 2.7 million to 4.8 million acres 
between 1972 and 1982. Likewise, the area of overstocked 
timberland (timberland more than 130 percent stocked with 
growing stock trees) increased from 0.9 million to 1.4 
million acres. 
Although radial increment of softwoods in the South Central 
region has dropped, the decline does not appear to have 
significantly lowered volume growth. The average net annual 
softwood growth per acre on pine types in the South Central 
region has actually changed very little in recent years, rising 
from 53 cubic feet per acre in 1970 to 56 cubic feet per 
acre in 1976 and falling to 54 cubic feet per acre in 1984. 
Net annual growth of softwood in the South Central region 
is projected to decline sharply through 1990 and then turn 
back up. In 1990, net annual growth of softwood is pro- 
jected to total about 2.6 billion cubic feet, or 8 percent 
below present levels. Beyond 1990, annual growth of 
softwood climbs back up to 3.7 billion cubic feet in 2030. 
Softwood growth on forest industry land continues to 
increase throughout the projection period, rising from 0.9 to 
1.6 billion cubic feet. Between now and 1990, softwood 
growth on other private land falls from 1.6 to 1.2 billion 
cubic feet. It then climbs back to 1.6 billion cubic feet. 
Currently, forest industry land produces about 34 percent of 
the softwood growth in the South Central region, a propor- 
tion that is projected to climb to 45 percent by 2000. 
Pine plantations are projected to provide an increasing share 
of the softwood growth. In 1984, net annual growth of 
softwood on pine plantations totaled 0.4 billion cubic feet, 
only 15 percent of the total. Compared to the Southeast, 
more of the plantations in the South Central region are in 
the sapling—seedling stage of development. Large areas 0! 
plantations will reach merchantable size by 2000, whe: 
proportion of softwood growth attributed to this type i 
projected to account for 58 percent of the total. S af 
growth on pine plantations in the South Central region i: 
projected to increase to 2.5 billion cubic feet and eventually 
account for two-thirds of the total. 
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