Formation and Properties of Juvenile Wood in Southern Pines
Formation and Properties of Juvenile Wood in Southern Pines

Author:

Publisher:

Published: 2001

Total Pages: 48

ISBN-13:

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To 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.

Size- and Age-Related Changes in Tree Structure and Function
Size- and Age-Related Changes in Tree Structure and Function

Author: Frederick C. Meinzer

Publisher: Springer Science & Business Media

Published: 2011-06-29

Total Pages: 511

ISBN-13: 9400712421

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Millions of trees live and grow all around us, and we all recognize the vital role they play in the world’s ecosystems. Publicity campaigns exhort us to plant yet more. Yet until recently comparatively little was known about the root causes of the physical changes that attend their growth. Since trees typically increase in size by three to four orders of magnitude in their journey to maturity, this gap in our knowledge has been a crucial issue to address. Here at last is a synthesis of the current state of our knowledge about both the causes and consequences of ontogenetic changes in key features of tree structure and function. During their ontogeny, trees undergo numerous changes in their physiological function, the structure and mechanical properties of their wood, and overall architecture and allometry. This book examines the central interplay between these changes and tree size and age. It also explores the impact these changes can have, at the level of the individual tree, on the emerging characteristics of forest ecosystems at various stages of their development. The analysis offers an explanation for the importance of discriminating between the varied physical properties arising from the nexus of size and age, as well as highlighting the implications these ontogenetic changes have for commercial forestry and climate change. This important and timely summation of our knowledge base in this area, written by highly respected researchers, will be of huge interest, not only to researchers, but also to forest managers and silviculturists.

Cellular Aspects of Wood Formation
Cellular Aspects of Wood Formation

Author: Jörg Fromm

Publisher: Springer Science & Business Media

Published: 2013-04-11

Total Pages: 265

ISBN-13: 3642364918

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With today’s ever growing economic and ecological problems, wood as a raw material takes on increasing significance as the most important renewable source of energy and as industrial feedstock for numerous products. Its chemical and anatomical structure and the excellent properties that result allow wood to be processed into the most diverse products; from logs to furniture and veneers, and from wood chippings to wooden composites and paper. The aim of this book is to review advances in research on the cellular aspects of cambial growth and wood formation in trees over recent decades. The book is divided into two major parts. The first part covers the basic process of wood biosynthesis, focusing on five major steps that are involved in this process: cell division, cell expansion, secondary cell wall formation, programmed cell death and heartwood formation. The second part of the book deals with the regulation of wood formation by endogenous and exogenous factors. On the endogenous level the emphasis is placed on two aspects: control of wood formation by phytohormones and by molecular mechanisms. Apart from endogenous factors, various exogenous effects (such as climate factors) are involved in wood formation. Due to modern microscopic as well as molecular techniques, the understanding of wood formation has progressed significantly over the last decade. Emphasizing the cellular aspects, this book first gives an overview of the basic process of wood formation, before it focuses on factors involved in the regulation of this process.

Wood Variation
Wood Variation

Author: Bruce J. Zobel

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 376

ISBN-13: 3642740693

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Wood is the usual end product of a forestry operation. Because of its importance, numerous studies have been made relative to wood prop erties, the causes of wood variation, and how best to develop wood for desired products. There is voluminous literature related to these subjects, but it is neither well known nor appreciated by foresters because the publications are often not available or are not well understood by the forester or by those who use the wood. Frequently, the literature is confusing and contradictory, making it difficult for the nonspecialist to use what information is available. In order to produce and use wood efficiently, the variation pat terns within trees, among trees within species, and among species must be understood. This also requires some knowledge of the causes of variation and the effects of different wood properties upon utiliza tion. The information about variation patterns, their causes, and con trol and effect upon the product must be known by the tree grower, the tree breeder, and the tree harvester as well as by those who ultimately convert wood into a final, salable product.