108 



THE OUTLOOK FOR TIMBER IN THE UNITED STATES 



overstocked, plus 26.5 million acres on which a 

 manageable stand was lacking and which would 

 contribute very little to the timber supply until 

 converted, planted, or regenerated (table 86) . Re- 

 sults of this analysis clearly indicated that within 

 each ownership class there is a large accumulation 

 of idle, nonstocked or poorly stocked acres where 

 planting, conversion, or regeneration will be 

 necessary if the large differences between pro- 

 spective and potential timber yields from the lands 

 are to be eliminated or reduced. 



Of the 10.7 miUion acres of young immature 

 stands identified as overstocked, a commercial 

 thinning opportunity was estimated to exist on 

 7.8 million acres. On the remaining 2.9 million 

 acres, it was judged that precommercial thinning 

 would be required to correct overstocking prob- 

 lems. 



3. The third step involved a breakdown by 

 broad management classes and by ownership of 

 the 26.5 million acres considered suitable for inten- 

 sive management but where there is an absence of 

 a management stand (table 87). These included 

 a range of types and stocking conditions. The 

 category of farm and miscellaneous private 

 ownerships accounted for a major part of the 

 total, with 20.8 million acres where conversion or 

 regeneration will be necessary to obtain satisfac- 

 tory yields. 



4. The fourth step involved an estimate of 

 current levels of forestry activities to aid in 

 determining additional areas where management 

 might be intensified. These data, based upon 

 estimates of past treatment and disturbance on 

 measured field plots, showed an estimated level 

 of forestry activities in 1970 as follows: 



Million 



Practice acres 



Harvesting 1. 7 



Intermediate cutting 1. 6 



Planting 0. 5 



Total 3. 8 



These data suggest that for the category of 

 farm and miscellaneous ownerships expected 

 accomplishments over the next decade with cur- 

 rent management would leave about 19.6 million 

 acres untreated. The make-up of this area is shown 

 in table 88 and figure 46. 



In this detailed analysis for the farm and mis- 

 cellaneous category of ownership, some 5 million 

 acres of hardwood types were eliminated from 

 detailed study, not because of the unimportance 

 of hardwoods, but rather because of primary 

 concern at this time over supplies of softwood 

 sawtimber. 



Estimated Increases in Yields 



The potential yields of pine plantations that 

 might be established on areas converted or regen- 

 erated vary widely depending upon site, species, 

 density, and age. Forest areas were, therefore, 



Forest conditions in the southeast, 1970 



total 

 66 3 



poor sites 



stands in good condition 



stands ready for harvest 



area treated annually 



area suitable 

 for treatment 



5 10 15 20 25 



MILLION ACRES 



Figure 46 



divided into good and medium sites in order to 

 take account of the considerable differences in 

 potential yields attributable to site differences. 

 Areas by site were estimated from Forest Survey 

 plot data, except for idle cropland where it was 

 assumed that half of the acreage available would 

 occur on good sites and half on medium sites. 



Available yield tables for slash pine and loblolty 

 pine were utilized in estimating potential increases 

 in harvests after allowances for understocking and 

 losses to destructive agents. 



Evaluation of thinning opportunities required 

 taking into account the product objectives of 

 forest landowners. Thus, for pulpwood production 

 many owners select spacings that do not require 

 thinning during the rotation. Others insist that 

 thinning must be financially advantageous, even 

 for pulpwood rotations. On the other hand, in 

 all-purpose management that includes both small 

 and large product objectives, thinnings will of 

 necessity play a role in maintaining stand struc- 

 ture and diameter growth. Also in overstocked 

 stands precommercial thinning may be an impor- 

 tant management opportunity. 



Estimates of increased future harvests obtain- 

 able from thinning treatment were developed by 

 a stand table projection method. 



In such growth projections, it was assumed that 

 the current program of prescribed burning would 

 be continued along with other protection activities. 

 Estimated yields necessarily included a substantial 

 allowance for probable losses in plantations and 

 in natural stands from destructive agents such 

 as fire, insects, and disease. Forest Survey findings 

 in this region indicate that mortality losses have 

 been reducing gross growth by an estimated 10 to 12 

 percent, while other growth losses resulted in 

 additional differences between current growth and 

 potential growth. 



