204 



That, however, does not seem to be the 

 case in Douglas-fir, much of which is 

 wide-ringed at the center because of 

 having come up in the open after fire, 

 storm, or cutting. 



Benson H. Paul, who is working at 

 the Forest Products Laboratory on the 

 relation of growth conditions to wood 

 quality, found that a reduction in 

 growth is particularly objectionable in 

 hardwoods used for purposes where 

 strength is essential, as with hickory 

 and ash for tool handles. If the rate 

 of growth is slowed down from, say, 5 

 to 17 rings an inch from youth to ma- 

 turity, the outer, slowly grown part is 

 apt to be exceptionally low in tough- 

 ness i n fact, more so than if the rate 

 of growth had not been rapid in youth. 



A tree of more uniform rate of 

 growth is more desirable for most lum- 

 ber uses than one that shows wide 

 variation in width of annual rings. 



Old-growth Appalachian oak and 

 yellow-poplar have a reputation for 

 being soft-textured because of their 

 slow or moderate growth rates in dense 

 stands and under soil and climatic con- 

 ditions not so conducive for rapid 

 growth as in the Mississippi Delta. 

 The indications are that second-growth 

 oak and yellow-poplar from the same 

 region, because of their more rapid 

 growth, will not be so soft-textured. 



Some species of trees, when grown 

 in swamps that are under water much 

 of the year, as in the lower Mississippi 

 Valley, usually have enlarged butts 

 that extend 6 to 10 feet above ground 

 and contain wood that is much softer 

 than the normal wood higher in the 

 trunk. This swell-butted material is of 

 inferior quality, but it occupies a rela- 

 tively large percentage of the volume 

 of the trunk in water tupelo, ash, and 

 baldcypress. On the other hand, some 

 species of oaks and cedar elm, which 

 grow well under the same conditions, 

 do not produce swelled butts having 

 lightweight wood. This is an important 

 point to consider in reforesting such 

 bottom lands. 



Observations on pines growing in 

 the sands of western Florida and Ne- 



Yearboo\ of Agriculture 1949 



braska show that strong, dense wood 

 will not be produced in trees that have 

 inadequate soil moisture during the 

 summer when the strength-giving sum- 

 mer wood is formed. The light wood 

 produced in trees growing under such 

 conditions has advantages, however, 

 for uses that do not require high 

 strength because the wood is easily 

 handled, easily worked, and does not 

 shrink and swell so much as denser 

 wood of the same species. It is import- 

 ant to know, however, that dense and 

 strong yellow pine cannot be produced 

 under adverse growing conditions in 

 summer. 



Experience and laboratory tests have 

 shown large variations in wood quality 

 in each species of timber. Considering 

 the differences that may occur even in 

 the same tree, it is evident that en- 

 vironment is responsible for much of 

 the variation. 



HEREDITY also has an important role. 

 There are indications that straight- 

 ness of trunk, limbiness, straight grain, 

 figured wood, and rapid growth are 

 hereditary, as well as resistance to dis- 

 ease, cold, and drought. Therefore, in 

 order to get the largest return from 

 timber growing, seed trees should be 

 selected with an eye to quality; young 

 trees of inferior quality should be elim- 

 inated early in a growing stand, and 

 trees retained for the final crop should 

 be given cultural treatment that will 

 insure wood of desirable characteristics 

 as far as is economically feasible. 



A compromise must usually be made 

 between quantity and quality. The 

 highest returns often are not obtained 

 by growing trees either as quickly as 

 possible in fairly open stands or at a 

 slow and uniform rate in dense stands 

 to produce wood of better quality. The 

 peak in profits usually lies somewhere 

 between the two extremes of growth. 

 Nor may it be economical to elimi- 

 nate all the defective trees and plant 

 pedigreed seedlings in their place. 

 Quality, however, should always be 

 kept in mind in managing forests for 

 wood production. 



