The quality of Douglas fir grown in the United Kingdom

Abstract

Within the UK there is a marked disparity in the end uses of home-grown timber compared with imported material. The country is nearly self-sufficient in the production of lower grade material, while that for use in construction, typically requiring higher quality, is up to 80% imported. The results presented in this work form part of a larger drive to better understand the quality of UK-grown timber. The study focuses on Douglas fir grown in the south-west of England, a region facing many challenges in delivering the full potential of its forest resource. A total of 24 trees were felled across the region. Variations in mechanical and anatomical properties with age and height were assessed, as was the extent of the typically undesirable juvenile wood zone. Results for all properties showed high variability at younger ages, stabilising as trees matured. The rate of growth of trees had little impact on the quality of the material produced. Results compared favourably with those reported in other studies conducted on the species internationally. Analysis of results also demonstrated potential improvements in wood quality and yield that may be achieved through the implementation of silvicultural practices such as continuous cover forestry.