The main objective of this study is to evaluate the grade yields and mechanical properties of Norway spruce (Picea abies (L.) Karst.) grown in Nova Scotia and New Brunswick. The four samples of Norway spruce trees selected for the study were processed into 530 dry 1x3 dimension lumber pieces. The investigators graded the lumber pieces according to both British and Canadian specifications, and estimated yields for selected visual and machine grades. They tested the pieces to determine their modulus of rupture, modulus of elasticity, and specific gravity. Comparisons were made between wood of two provenances: MS87 (German) and MS85 (Polish), and among lumber obtained from mature and juvenile stands. Comparisons are also presented between the Norway spruce data and spruce-pine-fir lumber data.
Reviews a study conducted to evaluate four samples of Norway spruce trees from four plantations in Nova Scotia and New Brunswick. The trees were processed into 2x4 lumber and tests focused on the quality of the wood when used as construction lumber. Specific objectives were to: evaluate yields when the material is sorted into various structural grades; determine bending properties; and compare wood properties of trees from one German and one Polish provenance. Results are summarized from tests of 530 pieces of lumber.
The book is a fundamental reference source on reaction wood for wood scientists and technologists, plant biologists, silviculturists, forest ecologists, and anyone involved in the growing of trees and the processing of wood. It brings together our current understanding of all aspects of reaction wood, and is the first book to discuss both compression wood and tension wood. Trees produce reaction wood to maintain the vertical orientation of their stems and the optimum angle of each branch. They achieve this by laying down fibre cell walls in which differences in physical and chemical structure from those of normal fibres are expressed as differential stresses across the stem or branch. This process, while of obvious value for the survival of the tree, causes serious problems for the utilisation of timber. Timber derived from trees containing significant amounts of reaction wood is subject to dimensional instability on drying, causing twisting, bending and splitting. It is also difficult to work as timber, and for the pulp and paper industry the cost of removing the increased amount of lignin in compression wood is substantial. This has both practical and economic consequences for industry. Understanding the factors controlling reaction wood formation and its effect on wood structure is therefore fundamental to our understanding of the adaptation of trees to their environment and to the sustainable use of wood. The topics covered include: -Morphology, anatomy and ultrastructure of reaction wood -Cell-wall polymers in reaction wood and their biosynthesis -Changes in tree proteomes during reaction wood formation -The biomechanical action and biological functions of reaction wood - Physical and mechanical properties of reaction wood from the scale of cell walls to planks -The detection and characterisation of compression wood -Effects of reaction wood on the performance of wood and wood-based products - Commercial implications of reaction wood and the influence of forest management on its formation
This book offers comprehensive information on the genomics of spruces (Picea spp.), naturally abundant conifer tree species that are widely distributed in the Northern Hemisphere. Due to their tremendous ecological and economic importance, the management of forest genetic resources has chiefly focused on conservation and tree improvement. A draft genome sequence of the 20-gigabase Norway spruce genome was published in the journal Nature in 2013. Continuous efforts to improve the spruce genome assembly are underway, but are hindered by the inherent characteristics of conifer genomes: high amounts of repetitive sequences (introns and transposable elements) in the genome and large gene family expansions with regards to abiotic stress, secondary metabolism and spruces' defense responses to pathogens and herbivory. This book presents the latest information on the status of genome assemblies, provides detailed insights into transposable elements and methylation patterns, and highlights the extensive genomic resources available for inferring population genomics and climate adaptation, as well as emerging genomics tools for tree improvement programs. In addition, this volume features whole-genome comparisons among conifer species, and demonstrates how functional genomics can be used to improve gene function annotations. The book closes with an outlook on emerging fields of research in spruce genomics.
