FOREST LAND AND TIMBEE 



137 



Because of the diversity of these factors and 

 because their importance varies among the dif- 

 ferent possible uses of wood, no single measure 

 can describe adequately the quality of the total 

 timber supply. Nevertheless, in recent years, tim- 

 ber and other surveys have been helpful in evalu- 

 ating the quality of young-growth, in indicating 

 the way quality is changing, and in showing trends 

 in quality requirements. 



Quality requirements for timber are of special 

 significance for they tend to place limitations on 

 the utility of the total timber supply. These limi- 

 tations stem from at least three aspects of timber 

 utilization: product specifications, product costs, 

 and product technology. 



Timber product specifications, except for bulk 

 products like pulpwood, chemical wood, and fuel- 

 wood, are higher — much higher in some in- 

 stances — than standards used in the timber inven- 

 tory. The low-grade saw log in the minimum saw- 

 timber tree, for example, is far too poor for the 

 manufacture of veneer or the upper grades of 

 lumber. Increased outlets for wood as cellulose 

 give added significance to estimates of sound wood, 

 but even in such markets the ratio of cull to sound 

 wood places a limit on what timber can be used. 

 Hence, timber volume estimates often must be 

 discounted to some degree before they become 

 realistic estimates of timber supply. 



Costs of logging and processing timber are in- 

 fluenced by tree and stand quality. Limby trees, 

 sparse stands, small trees, and numerous defects 

 all spell high costs for the end product. And with 

 knotty, crooked, or defective logs and bolts, even 

 the most efficient workei's equipped with the best 

 machinery cannot be as productive as those han- 

 dling high-quality timber. While specifications for 

 logs and bolts are often set with regard for the 

 manufacturer's break-even point, few manufac- 

 turers can operate for long with no raw materials 

 better than the minimum. To support stable and 

 profitable industries, the timber base must offer a 

 reasonable share of better-than-minimum quality 

 trees and stands. Thus, cost factors tend to limit 

 further the estimates of the timber supply. 



Product technology is closely related to quality, 

 too. Where the bulk of the timber is low-grade, 

 economic forces press for advancement in tech- 

 nology. And when such advances take place, 

 usually there is a downward revision in the 

 minimum specifications for quality. The cellulose- 

 based industries are a good example of this effect. 

 While gains in technical knowledge offset low 

 quality to some extent, there is a limit to what 

 technology can do. In many applications, wood is 

 used because it possesses certain intrinsic prop- 

 erties such as high strength-weight ratio, good 

 appearance, or workability. If these properties 



are missing, it probably will not be used. Thus, 

 if timber is grown without regard for quality in 

 terms of end use, many markets may be lost. 



There are many criteria of timber quality, 

 ranging from crude indicators to precise deter- 

 minations based on the requirements of a specific 

 product or end use. No single, all-inclusive 

 expression of quality is possible, because of the 

 wide variety of products made from wood. The 

 sawtimber-growing stock distinction already men- 

 tioned is one crude measure. The prevalence of 

 cull trees, species, and size are also relatively crude 

 indicators of quality in standing timber. Log and 

 tree grades are more reliable in that they predict 

 yields of lumber by grades with relatively good 

 accuracy . 



Log Grades Measure Tree Quality 



Log grades do not recognize all end-use require- 

 ments of timber, but they do reflect some of them 

 indirectly by taking into account diameter, length, 

 and amount and character of defects in individual 

 logs. The objective generally is to express prob- 

 able yield of lumber, by lumber grade, when the 

 logs are sawed. In the Southeast, for example, 

 a test of over 1,000 pine logs showed that Grade 1 

 logs yielded 75 percent of their volume in C and 

 Better lumber; Grade 2, 57 percent; Grades 3 and 

 4 combined, only 12 percent. Thus, the lower the 

 grade of the log the lower the percentage of high- 

 quality lumber. 



Log grades have been used to estimate the qual- 

 ity of much of the standing timber in the East. 

 For southern yellow pine, they indicate that the 

 lumber which could be sawed from present stands 

 would be less than one-fifth Grade C and Better, 

 one-fifth would be Number 1 Common, and more 

 than three-fifths would be Number 2 Common or 

 poorer. Much the same situation is shown by the 

 log grade distribution of hardwood sawtimber 

 volume (table 84). 



In eastern young-growth timber the high per- 

 cent of volume in Grade 3 logs has come about 

 gradually and through a number of causes. Fires, 

 disease, and insects have had much to do with the 

 present quality distribution. Economic condi- 

 tions have favored removal of the high-quality 

 sawtimber and the premature cutting of succes- 

 sively smaller trees. Logging damage to remaining 

 trees has frequently resulted in additional defect. 

 Many of the present young-growth hardwood 

 stands originated as stump sprouts; such sprouts 

 are subject to heart rot and also frequently arise 

 in multiple stems of poor form. 



That quality is a continuing problem is indicated 

 not only by the present status but also by suc- 

 cessive inventories. In the Lake States, timber 

 inventories by log grades in 1936 and 1953 show 



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