Table 20. — Average increment per acre, shown in board feet, cubic feet, and cords, 1934 (uninfluenced by cutting) 





Board feet (lumber tally) 



Cubic feet (inside bark) 



Cords 



Forest condition 



Pine 



Hard- 

 wood 



Cy- 

 press 



All 

 species 



Pine 



Hard- 

 wood 



Cy- 

 press 



All 

 species 



Pine 



Hard- 

 wood 



Cy- 

 press 



All 

 species 





-23 



86 



53 



4 



52 



22 

 2 

 0) 



3 



2 

 1 



32 



110 

 56 



4 



-7.5 



12.0 



14.8 



.2 



11.5 



9.0 



2.2 



.1 



0.5 



.4 

 .3 

 (') 



4.5 



21.4 



17.3 



.3 



-0.10 



.16 

 .21 

 .01 



0.17 



.14 

 .04 

 (>) 



0.01 

 .01 



(') 



0) 



08 



Second growth: 



31 





.25 





01 









45 



16 



2 



63 



8.3 



5.6 



.3 



14.2 



.12 



.09 



(0 



21 







1 Negligible. 



> The average increments per acre for all conditions except reproduction and clear-cut for 1934 are: board feet, 72; cubic feet, 16.5; and cords, 0.24. 



increase in volume of all trees 5.0 inches d. b. h. 

 and larger, plus the volume of those trees reaching 

 5.0 inches d. b. h. during the year, minus mortality. 

 Growth prior to cutting of trees removed from the 

 stand during the year has been included. 



Table 19 shows the increment, all conditions 

 combined, in board feet and cubic feet (inside bark) 

 by species groups for the 3-year period 1934-36. 



Average Increment per Acre 



The average increment for 1934, uninfluenced by 

 cutting (table 20), for the entire area and for all 

 species groups combined amounts to 63 board feet 

 of saw-timber material per acre, or one-fifth cord 

 of all material. Since in calculating the increment 

 per acre it is assumed that no trees are removed 

 from the stand for commodity drain during the 

 year, the figures are slightly higher than those which 

 may be derived from table 18, where only the 

 growth prior to cutting was taken into account for 

 trees removed. 



Effect of Turpentining on Increment 



Although longleaf and slash pine have the ad- 

 vantages of dual-purpose trees, those turpentined 

 pay a very heavy toll in reduced increment. Deep 

 chipping, inserting tins too deeply, cupping small 

 trees, overcupping, and failing to protect resting 

 or worked-out trees from fire have retarded the 

 diameter growth of the individual trees, reduced 

 their volume of merchantable timber, and in- 

 creased the number of trees lost through insects, 

 wind throw, and fire. Fires have prevented much 

 of the area from fully restocking. 



Board-foot and cordwood comparisons of the 



actual growth of the timber when turpentined with 

 that of the timber if it had been left round, are 

 given in table 21. The actual mortality of the 

 timber when turpentined and the mortality of the 

 same timber if left round is also listed, together with 

 the volume of turpentine butts that it is assumed 

 will be lost during the working period of the virgin 

 crops hung in 1934. 



Table 21. — Effects of turpentining on forest increment, 1934 1 





If left round 



As turpentined 



Turpentining 

 net loss 



Growth 



Mortality _ 



Loss in butt vol- 

 ume.. 



M board 



feet 

 657, 300 

 107, 200 



M cord? 



1,367 



319 



M board 



feet 

 342, 600 

 407, 500 



M cords 



849 



1,675 



M board 



feet 

 314, 700 

 300, 300 



49,900 



M cords 



518 

 1,356 



75 















Total loss.- 











664, 900 



1 949 















1 Board-foot volumes expressed as lumber tally, based on International 

 J 4 -inch rule. 



The working of small trees under 9 inches d. b. h., 

 along with the accompanying excessive mortality, 

 not only is responsible for a large share of the nega- 

 tive increment in cords, but also reduces the possi- 

 bility of a future cut of high-quality timber and 

 endangers the stability of those industries dependent 

 upon saw timber. Under improved naval stores 

 practices, adequate fire protection, more intensive 

 forest management, and improved utilization, the 

 enormous loss in 1934 of approximately 665 million 

 board feet, lumber tally, or almost 2 million cords 

 of material of all sizes (table 21) could have been 

 reduced appreciably. Such reduction is most de- 

 sirable in order that there may be more timber for 

 the wood-using industries, which furnish much- 

 needed jobs and add to the general wealth of the 

 community. 



42 



