APPENDIX — CRITERIA FOR RATING PRODUCTIVITY 



675 



Table 86. — Prospective stocking of loblolly-shortleaj pine in the South Atlantic, Southeast, and Gulf Regions, 



by seed-tree size class 



Diameter breast 







Prospective stocking percent 



when 



number of seed trees per acre 



IS — 







high (inches) 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 



10 



12 



6 



8 



10 



13 



22 



13 

 16 

 20 



27 

 44 



20 

 24 

 30 

 40 

 67 



25 

 32 

 40 

 53 



89 



30 

 40 

 50 

 67 

 100 



37 

 48 

 60 

 80 



45 

 56 

 70 

 93 



51 



64 



80 



100 



59 

 72 

 90 



65 



80 



100 



71 



88 



77 

 96 



84 

 100 



90 



97 



100 



14 - 









16 --..-. 















18+ 











































1 



J 



Prospective Stocking 



Since the area was not fully stocked, the pros- 

 pects of future stocking were considered. The 

 following pine seed trees were observed on a 

 concentric 1-acre plot: one 10 inches d. b. h.; one 

 12 inches d. b. h. ; two 14 inches d. b. h. These 

 were tallied under "Seed trees per acre" on the 

 field worksheet, and the corresponding prospec- 

 tive stocking percentages shown in table 86 were 

 recorded. This table was derived from the basic 

 standards presented on page 689. 



The sum of the ratings for the various seed 

 trees was 34 percent. In other words, the seed 

 trees remaining were estimated to be capable of 

 producing seed enough to restock the plot to 34 

 percent of full stocking. Other seed sources were 

 considered, such as seed from adjoining uncut 

 stands of seed-bearing trees. The center of this 

 plot was 6 chains from a seed wall of uncut pines. 

 This was recorded under "Other seed sources 

 (distance in chains)." The corresponding pro- 

 spective stocking (30 percent) was taken from the 

 appropriate seed source standard (page 690) which 

 indicated that 30-percent stocking will result, on 

 the average, from seed dispersed from a source 

 5% to 6)2 chains distant. 



Therefore, sufficient seed was expected to fall 

 on this K-acre plot to restock the unstocked por- 

 tion of the area 64 percent of full stocking: Seeds 

 from seed trees, 34 percent + seeds from seed 

 wall, 30 percent=64 percent. This sum was 

 recorded under the column heading "Total pro- 

 spective stocking (percent)." 



The field examiner then estimated the percent- 

 age of the K-acre plot that was capable of being 

 restocked by the seed source. In this example, 

 54 percent of the area was occupied by existing 

 stocking, which left 46 percent unstocked. If 

 there were cull trees, brush, or other adverse 

 conditions on a portion of the unstocked area, 

 the portion so occupied was deducted to arrive 

 at the proportion of the plot area estimated to 

 be capable of restocking. Grazing damage and 

 other factors were considered in arriving at the 

 entry made here. In this case, for example, it was 

 determined that cull trees, brush, etc., occupied 



16 pei'cent of the plot area that was not stocked, 

 leaving only 30 percent of the area available for 

 future stocking. 



The final prospective stocking estimate then 

 was computed as the product of the "Total 

 prospective stocking (percent)" and the "Pro- 

 portion of plot area restockable," or 64 X .30=19 

 percent. This added to the total existing stocking 

 (54-i-19) = 73 percent. The final prospective 

 stocking percentage added to the percentage of 

 adjusted existing stocking gives a total adjusted 

 rating of 61 percent, i. e., 19-f42 = 61. The final 

 productivity rating for the area would be 61 

 percent if the timber was not cut prematurely, 

 or if the cutting was only a partial cut. However, 

 the example assumes a heavily cut, uneven-aged 

 stand, which requires calculation of a weighted 

 rating. 



Effect of Felling Age 



In this example, the following stumps were 

 recorded, by species, on the field worksheet: 



Diameter 



inside bark Age 



Species; (inches) {years) 



1 lobioUy pine 12 40 



1 shortleaf pine 10 35 



Do 10 30 



2 shortleaf pine 8 30 



3 shortleaf pine 6 25 



1 shortleaf pine 6 30 



2 loblolly pine 8 25 



1 shortleaf pine 12 50 



2 nongrowing pines ' 6 



' These two stock trees appeared to have been severely 

 suppressed or defective. 



The stocking factors were then recorded from the 

 existing-stocking table (table 85). D. i. b. on 

 stump was considered to be d. b. h. for this 

 purpose. 



The felling factors were read from the standards 

 showing the proportion of peak mean annual 

 growth reached at various ages by different spe- 

 cies cut for cordwood (table 102, columns 3 and 

 5). These were recorded in the column headed 



