252 



TIMBER RESOURCES FOR AMERICA'S FUTURE 



only is considered. The effects of species com- 

 position and premature cutting in modifying the 

 stocking rating will also be discussed separately. 



Stocking Most Significant Element 

 IN Productivity 



Existing stocking as determined by the survey 

 of recently cut land consists of crop trees left on 

 the ground after cutting plus any which may have 

 become established between the time cutting was 

 completed and the date of examination by the 

 survey. This interval varied from 7 years to 

 only a few months. Frequently then, the field 

 examination occurred at a time when stocking of 

 new growth was incomplete and changing rapidly, 

 especially on clear cuttings. Thus, any analysis 

 of existing stocking alone could easily prove mis- 

 leading with respect to future productivity on 

 recently cut lands. After careful estimates of the 

 prospects for further stocking are made and added 

 to existing stocking, the resulting totals give a 

 much better measure of the probable effect of 

 stocking on growth following cutting. 



Total stocking shows many significant varia- 

 tions by both major sections of the country and 

 by ownership classes, but it consistently exerts the 

 greatest influence of the several elements contrib- 

 uting to the combined productivity ratings. For 

 example, figure 83 shows that 40 percent of re- 

 cently cut land on small private ownerships was 

 found to be in the upper productivity class. It 

 shows further that the remaining 60 percent, which 

 constitutes a deduction from a feasible 100 per- 

 cent, consisted of 43 percent due to total stocking 

 on the ground which fell below the 70 percent 

 minimum required by the upper stocking stand- 

 ard, 6 percent due to the composition standard 

 not being met, and 11 percent due to premature 

 cutting. A similar relation between total stock- 

 ing and the other rating elements was found for 

 each broad ownership class and major section of 

 the country. 



Stocking Poorest on Small Ownerships 



On the basis of total stocking (existing plus 

 prospective), 74 percent of all recently cut lands 

 meet standards for the upper level of stocking 

 (table 147 and fig. 84). However, there are 

 marked differences between broad ownership 

 classes. Little over half (57 percent) of the re- 

 cently cut lands in small ownerships have attained 

 upper level stocking standards as compared to 

 slightly more than 80 percent for private owners 

 of medium and large size and for public forests. 

 The major stocking deficiencies on these small 

 ownerships are in the South and West. Here the 

 proportion of recently cut lands qualifying for 

 upper stocking standards is substantially below 

 the national average for all ownerships. Over 30 



percent of all commercial forest lands are in the 

 small ownerships of these two sections. Stocking 

 on small ownerships of the North about equals 

 the national average for stocking. This is partly 

 due to the large proportion of hardwood types 

 where establishment of reproduction is relatively 

 easy. 



Lack of Provision for Future Crops Responsible. — 

 Prospects of future stocking are much poorer for 

 small ownerships than for other classes. Com- 

 parisons of existing and total stocking for the 

 continental United States shows that on small 

 ownerships only 19 percent of recently cut lands 

 qualify for upper stocking standards on the basis 

 of prospective stocking only (table 147). Com- 

 parable increases for other ownership classes equal 

 or exceed 30 percent. Small private ownerships 

 show a similar weakness with respect to prospec- 

 tive stocking in all three major sections of the 

 country. 



Conditions on the ground after cutting that 

 affect the establishment of new tree crops are, 

 therefore, much less favorable on small private 

 ownerships than on others. Corrective measures 

 require a variety of positive actions. These vary 

 widely by forest types, methods of cutting used, 

 economic possibilities, and other factors. In 

 some situations, only one or two simple changes 

 may accomplish great improvement — in others a 

 more complex combination of treatments is re- 

 quired. 



Stocking Deficiencies Greatest 

 in the South 



The proportion of recently cut lands meeting 

 upper standards for total stocking is 83 percent 

 in the North and 77 percent in the West. These 

 proportions both exceed the national average of 

 74 percent. However, the score for total stocking 

 in the South — 65 percent — is considerably below 

 the national average. 



Recently cut areas on public lands in the 

 South have met upper standards for total stocking 

 as well or better than public lands elsewhere. 

 The comparatively low rating in the South is due 

 primarily to the conditions found on private 

 lands and particularly on small private ownerships. 

 Only 48 percent of recently cut lands in small 

 southern ownerships met high standards for total 

 stocking, the poorest stocking in the country. 

 The fact that half of the operating area in the 

 South was found to be in these small ownerships 

 is primarily responsible for the low overall stocking 

 in this section. The proportion of recently cut 

 lands meeting upper standards for stocking on 

 medium and large private ownerships of the 

 South exceeds the national average but is lower 

 than for this class of ownership in either North 

 or West. 



J. 



