A Survey of the Wood Density, Tracheid Length and Latewood Characteristics of Radiata Pine Grown in New Zealand
Author: J. Maddern Harris
Publisher:
Published: 1965
Total Pages: 31
ISBN-13:
DOWNLOAD EBOOKRead and Download eBook Full
Author: J. Maddern Harris
Publisher:
Published: 1965
Total Pages: 31
ISBN-13:
DOWNLOAD EBOOKAuthor: R. K. Bamber
Publisher: C.A.B. International
Published: 1983
Total Pages: 104
ISBN-13:
DOWNLOAD EBOOKAuthor:
Publisher:
Published: 2001
Total Pages: 48
ISBN-13:
DOWNLOAD EBOOKTo satisfy the increasing demand for forest products, much of the future timber supply will be from improved trees grown on managed plantations. This fast-grown resource will tend to be harvested in short age rotations and will contain higher proportions of juvenile wood than that of current harvests. In anticipation of this resource, definitive information is needed on the influence of juvenile wood on lumber properties so that grading rules and the associated allowable design stresses can be modified as needed. This document reports the results of an extensive review of the literature on juvenile wood in southern pines. This report defines and discusses the extent, occurrence, and characteristics of juvenile wood. It reviews the effects that environment and silviculture have on the amount of juvenile wood produced. Finally, the impacts that juvenile wood has on mechanical properties were quantified. The results of this quantification are significant to all producers of fast-grown plantations. Research has clearly shown that juvenile wood will have a detrimental impact on allowable design stresses for visually graded lumber. It is critical that methods are developed to more carefully manage fast-grown plantation wood for its most efficient use. This review should serve as an overall collection of knowledge pertaining to juvenile wood research in southern pines and should help in the decision-making efforts to improve seedling selection techniques and silvicultural practices to maximize the potential for fast-grown plantations of southern pines.
Author:
Publisher:
Published: 1979
Total Pages: 604
ISBN-13:
DOWNLOAD EBOOKAuthor: Bruce J. Zobel
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 351
ISBN-13: 3642795145
DOWNLOAD EBOOKOver the past years, a great deal has been learned about variation in wood prop erties. Genetic control is a major source of variation in most wood properties. Wood is controlled genetically both directly in the developmental or internal pro cesses of wood formation and indirectly by the control of tree form and growth patterns. Emphasis in this book will be on the internal control of wood production by genetics although there will be two chapters dealing with the indirect genetic control of wood, which was covered in detail in the previous book by Zobel and van Buijtenen (1989). The literature on the genetics of wood is very variable, SO'lle quite superficial, on which little reliance can be placed, and some from well-designed and correctly executed research. When suitable, near the end of each chapter, there will be a summary with the authors' interpretation of the most important information in the chapter. The literature on the genetics of wood can be quite controversial. This is to be expected, since both the environment and its interaction with the genotype of the tree can have a major effect on wood properties, especially when trees of similar genotypes are grown under widely divergent conditions. Adding to the confusion, studies frequently have been designed and analyzed quite differently, resulting in conflicting assessments of results.
Author: John Alexander Kininmonth
Publisher:
Published: 1991
Total Pages: 240
ISBN-13:
DOWNLOAD EBOOKAuthor:
Publisher:
Published: 1991
Total Pages: 612
ISBN-13:
DOWNLOAD EBOOKAuthor: H. A. I. Madgwick
Publisher:
Published: 1994
Total Pages: 448
ISBN-13:
DOWNLOAD EBOOKAuthor: Bruce J. Zobel
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 311
ISBN-13: 3642721265
DOWNLOAD EBOOKThe trend in forestry is toward shorter rotations and more complete utiliza tion of trees. The reasons are: (1) financial pressures to obtain rapid returns on the forestry investment made possible by an earlier harvest; (2) enforced harvest of young plantations to maintain a continuing supply of cellulose for mills where wood shortages are experienced; (3) thinning young plantations, both because they were planted too densely initially and because thinning is done where long rotation quality trees are the forestry goal; (4) more intensive utilization is being done using tops and small diameter trees; and (5) there is interest in using young (juvenile) wood for special products because of its unique characteristics and the development of new technologies. The largest present-day source of conifer juvenile wood is from thinnings of plantations where millions of hectares of pine were planted too densely. Because of the better growth rate resulting from improved silviculture and good genetic stock, plantations will need to be thinned heavily. As a result of this trend, young wood makes up an increasingly larger proportion of the total conifer wood supply each year. Large amounts of juvenile wood from hard woods are also currently available, especially in the tropics and subtropics, because of the fast growth rate of the species used, which results in shorter rotations and ess~ntially all juvenile wood.