Gross Influences on Heartwood Formation in Black Walnut and Black Cherry Trees


Book Description

Heartwood formation in black walnut (Juglans nigra L.) and black cherry (Prunus serotina Ehrh.) was studied in relation to tree age, size, and growth rate, vertical position in tree, morphological characteristics of heartwood-sapwood transition zones, between-tree and between-stand variation, and the broad-organizations of physiological control over the process. Heartwood formation (near ground level) commences at 3-8 years tree age in walnut, 3-9 years in cherry. In walnut, both between-stand and between-tree variation contribute significantly to total variation in sapwood ring number. In cherry, of these two sources of variation, only between-tree variation is important. Walnut shows little correlation between number of sapwood rings and recent rates of radial growth, while cherry exhibits a compensation for fast radial growth through a reduction in the number of sapwood rings. Results indicate that sapwood will be excessively wide in walnut grown under intensive culture in the absence of genetic or silvicultural control of heartwood formation, and that such control is biologically feasible.













Black Walnut in a New Century


Book Description

Presents papers and abstracts relating to genetic improvement, nursery production, plantation establishment, natural stand management, pest management, agroforestry and economics of black walnut and related Juglans species.













The Structure, Biosynthesis, and Degradation of Wood


Book Description

Forest trees constitute one of the major resources of the world and their utilization, either for structural purposes or for the materials which they yield, dates back to antiquity. Over the centuries, the exploitation of this resource has become progressively more sophisticated, and, in many parts of the world has led to the development of highly complex forest-based industries. The research and development work which led to these industrial uses fostered the formation of numerous technical societies and associations, which, through their meetings and publi cations, have facilitated communication and the exchange of ideas. Over the years, there have been numerous symposia devoted to wood and the many facets of its properties and utilization. However, rarely has the emphasis in such symposia been placed upon the living tree and the changes which it undergoes in relation to its ultimate utilization. Hence the Phytochemical Society of North America arranged the symposium, "The Structure, Biosynthesis, and Degradation of Wood", held at the University of British Columbia in August, 1976. the contributions to which form the basis of the present volume.