258 



TIMBER RESOURCES FOR AMERICA'S FUTURE 



thinnings or other partial cuttings in those which 

 have not completed their growth cycle would 

 help to raise the national level of growth. 



Premature Cutting Sometimes 

 Unavoidable 



In passing, it should be noted tliat often a 

 small amount of premature cutting is unavoidable 

 or even of advantage to the long-range main- 

 tenance or improvement of growth. Individual 

 logging units on large forests frequently cover 

 considerable acreages and may contain small 

 patches or stands of immature but operable tim- 

 ber. In some situations, such as mountainous 

 areas mainly of old-growth timber, the methods 

 of logging necessary are such that the small area 

 of young stands cannot be reserved from cutting. 

 Or they may pass the period of peak growth 

 before another cut in the area is possible. In such 

 cases, premature cutting is to be expected. 



A situation sometimes occurs where premature 

 cutting is advantageous to maintenance of growth. 

 This occiu's wliere past fires of large size, rapid 

 liquidation cutting, or a combination of both was 

 followed by development of a single age class or 

 very few age classes of young timber. Unless 

 premature cutting is carefully done to develop 

 a better distribution of age classes, large areas of 

 timber will mature more rapidly than they can be 

 harvested, with the result that in some species 

 losses in yield due to overmaturity may equal or 

 exceed those due to premature cutting. The 

 aspen tvpe of the Lake States is an example of 

 this. 



Thus, a controlled amount of premature cutting 

 has a definite and constructive part to play where 

 long-range plans are aimed at attaining an ulti- 

 mate balance of age classes for sustained yield of 

 forest products. However, situations where pre- 

 mature cutting is beneficial in any sense are few 

 and occur on only a small fraction of the recently 

 cut lands in any of the three sections of the 

 country. 



Study by Forest Type Groups Fur- 

 ther Identifies Deficiencies 



The foregoing discussion helps define the 

 geographic areas, ownership classes, and condi- 

 tions of recently cut lands responsible for limiting 

 the national level of growth insofar as timber 

 cutting is concerned. This can be sharpened 

 considerably by consideration of forest type in 

 addition to the factor of ownership class and 

 productivity elements. 



Statistics of table 149 provide the basis for 

 comparing the proportions of recently cut lands 

 in the upper productivity class for eacli forest 

 type group with tlie national average. These 



statistics also provide by type groups a basis 

 for appraising the effect of each rating element 

 on the proportion of recently cut lands in the upper 

 class. Such appraisals can also be made by broad 

 ownership groups. 



Softwood Type Groups of East and 

 West Contrast Sharply 



In the tabulation on the next page, productivity 

 on recently cut lands for each type group is com- 

 pared to the national average by summary of data 

 from table 149. The area of commercial forest 

 land in each type is also shown (from table 21, 

 appendix section Basic Statistics). 



The first part of the tabulation shows that the 

 nine type groups with recently cut lands exceeding 

 the national average in productivity contain 

 about one-third of all commercial forest land in 

 the United States. The strongest component 

 consists of six western forest type groups. Their 

 total area is about twice that of the maple-beech- 

 birch and aspen-birch type groups, which are the 

 only two eastern type groups where recently cut 

 lands exceed the national productivity average. 

 The absence of eastern softwood type groups is 

 noteworthy. Only two western softwood type 

 groups did not qualify for this category. 



Two eastern softwood type groups — spruce-fir 

 and longleaf-slash pine — are tlie only ones with 

 recently cut lands approximating the national 

 productivity average. Together they comprise 

 nearly 10 percent of all commercial forest land in 

 the country. Both are highh- important in the 

 sections where they occur. 



The recently cut lands of all otlier eastern 

 softwood and mixed hardwood-softwood t^'pe 

 groups are below the national productivity average 

 and constitute major weak spots. The loblolly- 

 shortleaf pine type group is the largest softwood 

 type group in the country and is included in this 

 category. Eastern type groups producing soft- 

 woods with recenth^ cut lands showing produc- 

 tivity below the national average contain 27 

 percent of all commercial forest land. In addi- 

 tion to these, two western type groups — western 

 white pine and larch — are also weak spots. To- 

 gether they occupy 2 percent of all commercial 

 forest land. 



Softwoods supply the higliest proportion of our 

 annual timber cut from growing stock. During 

 1952, in all regions, the cut of softwoods from living 

 trees 5 inches or more in diameter was 7.5 billion 

 cubic feet or 69 percent of the 10.8 billion cubic- 

 foot total (table 49, appendix section Basic 

 Statistics). In view of their current importance 

 and the tight softwood supply situation projected 

 for the future, the absence of eastern softwood 

 type groups in the better-tlian-average category 

 is of considerable national significance. 



