46 



TIMBER RESOURCES FOR AMERICA' S FTJTTRE 



Also of special significance is saw timber growth 

 and cut in contrast to growing stock. About 84 

 percent of the timber cut is saw timber and, even 

 with generous allowance for improved utilization, 

 future use will continue to be heavily weighted to 

 saw timber. For these reasons, greater emphasis 

 is given to sawtimber in the subsequent summary. 



In appraising timber growth and timber utiliza- 

 tion or cut, care should be taken not to over- 

 emphasize or misuse broadly generalized growth- 

 cut balances. There is a popular tendency to 

 believ^e that if overall national comparisons 

 indicate that growth exceeds cut, the forest 

 situation is favorable, and if cut exceeds growth, 

 the reverse is true. Neither conclusion is justified. 

 Significant comparisons of growth and cut are the 

 relationships by species, or by softwoods and 

 hardwoods, or by certain regions. Even here 

 care must be taken not to confuse growth-cut 

 ratios based on old-growth timber with those for 

 second growth, or ratios for growing stock with 

 those for sawtimber, nor to overlook the level at 

 which the balance or unbalance may occur. 

 Erroneous use of growth-cut relationships is the 

 most frequent misinterpretation of findings of the 

 Timber Resource Review. 



Growth Is Increasing 



Timber growth as used in the Timber Resource 

 Review is net growth, which means growth after 

 deductions for mortality. In this respect it differs 

 from the growth estimates in the 1945 Reap- 

 praisal report of the Forest Service which used 

 gross growth or growth before deductions were 

 made for mortality. The 1944 estimates are also 

 not directly comparable because of changing in- 

 ventory standards over the years. For this and 

 other reasons, the 1944 estimates have been ad- 

 justed in the subsequent disciission to permit rea- 

 sonably valid comparisons with 1952. Annual 

 growth includes the growth of timber on hand at 

 the beginning of the year plus the total volume of 

 young timber that becomes measurable during the 

 year (commonly referred to as "ingrowth"). 



As in the Reappraisal, growth estimates apply 

 to the year preceding the date of inventory. The 

 inventory estimates were made as of January 1, 

 1953, but they are referred to as "1953" estimates. 

 The growth period is the calendar year 1952. 



Growth Up 9 Percent Since 1944 



It is significant and reassuring that sawtimber 

 growth in 1952 was apparently 9 percent greater 

 than the adjusted 1944 level (table 28 and fig. 21). 



The change is even more significant in the second 

 growth of the East. Here softwood and hard- 

 wood sawtimber growth increased 11 and 16 

 percent, respectively, over 1944. The percentage 

 increases in growing-stock growth were somewhat 

 more pronounced. 



In the West, indications are that sawtimber 

 growth decreased 3 percent betw'een 1944 and 

 1952, and growing-stock grow^th showed a 2- 

 percent decline. As old-growth areas in the West 

 are cut and second-growth stands reach measur- 

 able size, western growth should substantially 

 increase. Considering the large areas of second 

 growth in the West, it would be expected that 

 western growth would be greater in 1952 than in 

 1944. A probable explanation of the decrease is 

 unusually high mortality due to bark beetle 

 attacks in the Northern Rockies, and premature 

 cutting of second-growth timber mainly on small 

 private ownerships in the Northwest. 



Mortality of timber by causative agents, un- 

 portance, and geographical occurrence is sub- 

 sequently discussed in this summary and also in 

 the section on Forest Protection. Total mortality 

 (without reference to amounts salvaged) is show-n 

 near the bottom of table 29, where it is apparent 

 that mortality is equivalent to about 25 percent 

 of net growth of both sawtimber and growing 

 stock, and is much higher in softwoods than in 

 hardw'Oods. If mortality could be substantially 

 reduced, it would be one of the most effective 

 measures to extend the available supply of timber. 



One-Half of the Nation's Timber Growth Is in 

 the South 



The South leads the Nation in growth of both 

 sawtimber and growing stock. Likewise, it leads 

 both West and North in softwood growth, and lags 

 onl}' slightly behind the North in growth of hard- 

 woods. Of the national total of 47.4 billion board- 

 feet of sawtimber growth in 1952, 51 percent 

 occurred in the South. Over 20 percent occurred 

 in the Southeast region alone — almost equal to the 

 sawtimber growth in the entire West (table 29). 

 In terms of growing stock, with a national total 

 of 14.2 billion cubic feet, the South grew 48 percent 

 or 6.8 billion. Growth in the West continues to 

 be held down by the large residual of old-growth 

 timber which has little net growth. 



Sixty percent of all sawtimber growth in the 

 South is softwoods, as well as half of all growing- 

 stock growth. Only in the North do hardwoods 

 dominate the growth picture and there nearly 

 four-fifths of the sawtimber growth is in hard- 

 woods. 



