Timber utilisation for the silviculture and processing industries

 

Summary

Felled trees marked to help in the measurement of branch size, orientation, and stem taper

Logs in the log yard prior to being processed

The main aim is to assist with industry in proactive research related to timber problems to aid in better management regimes and problem solving for the silviculture and processing industries. The main areas of research include:

• Studies to identify causes of increased failure during stress grading
• Identifying, using destructive and non-destructive testing methods, problem areas and stands within the region of interest (ROI). Identifying poorer material during harvesting.
• Maximising value using processing technology
• To make recommendations in relation to stress-grading and x-ray grading of timber within poorer quality stands.

Detailed objectives

This work is intended as a major pilot study to determine whether it is realistic to make forecasts of the quality of sawn timber coming from South Scotland spruce forests over the next 20 years and whether methodologies for identifying poorer quality material can be developed. Specifically the objectives are:

• To develop non-destructive testing methods for identifying the types of stands of Sitka spruce within South Scotland that will produce poor quality sawn timber
• To make use of the existing Sitka spruce stem straightness database and the methodologies developed above to identify the areas and volumes of Sitka spruce of different qualities likely to come on the market in the next 20 years
• To develop methods for identifying different qualities of material during harvesting
• To develop methods for identifying different qualities of material in the sawmill log yard, using acoustics
• To test non-destructive methods for identifying poor quality saw logs on the saw-line
• To destructively test samples from three areas with potentially different qualities of sawn timber in order to correlate the quality identification methods developed above with actual sawn timber properties and performance
• To report to the sawmilling and forest industries in South Scotland on the scale of the problem caused by poor quality saw logs in the region and recommend methods for reducing the impact of such material.

Forestry Commission policy

Timber is one of the key themes of the Scottish Forestry Strategy. This project will contribute to several of the requirements identified in the Strategy, namely:

• To maximise the economic potential of Scotland’s timber resource
• To encourage continued investment in timber processing by sustaining a predictable and stable supply of good quality timber
• To promote the use of timber as a renewable, versatile raw material
• To increase the efficiency of the timber supply-chain to improve sector competitiveness, and minimise the social and environmental impacts of timber transport
• To encourage continuing development of the hardwood timber sector in Scotland.

Methods

Marking battens in the sawmill in order to link the performance of sawn timber with site and stand characteristics

From the work, we aim to establish whether there are clear connections between product performance from sites of different quality classes and site and stand characteristics:

• Use the connections between site and stand characteristics and sawn timber performance, together with the Stem Straightness survey of South Scotland (Stirling et. al, 2000), to develop a predictive model of sawn timber quality.
  Protocol for stem straightness assessment in Sitka spruce ^(PDF-135K)
• Make an assessment of areas (ha) in South Scotland falling into each quality class based on the Forestry Commission sub-compartment database using acoustic tools.
• Use production forecasting to estimate the volumes that will be available from each quality class during different felling periods over the next 20 years, both from public and private sector forests.
• Test methodology by identifying 3 harvesting sites of each quality type (9 sites in total) from sub-compartment database and checking against field measurements in each stand (stem straightness, branch size, branch insertion angle, acoustic velocity etc.) and C16 outturn at the sawmill.

Associated projects

• Lodgepole pine moisture content project.  Balcas Timber Ltd.
  Evaluating moisture content in lodgepole pine logs for use in CHP plants as wood fuel.
• The utilisation of lodgepole pine. James Jones and Sons Ltd.
  The timber properties of three provenances of lodgepole pine in relation to end product usage.
  Utilisation of lodgepole pine ^(PDF-3850K)
• The impact of genetic variation on timber properties
  A study comparing the genetic differences of three progeny in relation to timber properties.
• Sourfelling: Moisture content variations in Lodgepole pine over time
  This project was established to measure the variation in initial moisture content and the drying rate after felling of whole tree Lodgepole pine timber.
• Acoustic testing for timber properties
  Using acoustic tools to identify timber quality in Sitka spruce relating to Modulus of Elasticity.
• Model-D House build
  Using homegrown timber from improved progeny of Sitka Spruce to build an affordable, carbon neutral house demonstrating the many diverse uses of our timber.

Seminar presentations

The seminar "Evaluating and classifying timber for the wood processing industry"  (April 2008) reviewed research with emphasis on its application to predominant commercial species in the South-West England.

• Broadleaf Timber Quality ^(PDF-1362K)
• Douglas fir - Pseudotsuga menziesii (Mirb.) Franco - Characteristics and potential ^(PDF-1503K)
• Forestry of the South West for future construction ^(PDF-4607K)
• Resource assessment for South West England ^(PDF-647K)
• Timber utilisation for the industry (TUFTI) ^(PDF-2276K)
• Understanding the variability in the wood properties of home-grown timber ^(PDF-1064K)

Status

The project started in March 2006.

The initial report has been published and further work is progressing. January 2007 presented a unique opportunity and collaboration in continuing this work with the secondment of Shaun Mochan to James Jones for a period of 6 months to try and evaluate and update the findings relating to timber quality in Scotland for processing industries.

Other work such as sourfelling and genetic variation on timber properties are ongoing and should be completed with published papers and information notes by the end of 2007.

Project funders, partners and people

Contact

Shaun Mochan
Forest Management Division
Forest Research
Northern Research Station
Roslin
Midlothian
EH25 9SY

Tel: +44 131 445 6986
Fax: +44 131 445 5124
Email: shaun.mochan@forestry.gsi.gov.uk

References

Stirling, G., Gardiner, B., Connolly, T. and Mochan, S.E. (2000). A Survey of Sitka Spruce Stem Straightness in South Scotland. Final Report.  Forest Research.

About this project

Project funders

• Forestry Commission Scotland
• James Jones and Sons Ltd – Larbert, Falkirk
  

Project partners

• Centre for Timber Engineering - Napier University, Edinburgh
• Howie Forest Products Ltd – Kenmuir Sawmills, Dalbeattie
• James Jones and Sons Ltd – Larbert, Falkirk
• Swedish Pulp and Paper research institute (STFI), Stockholm
• Microtec Biovision – Italy
• Balcas Timber Ltd, Enniskillen, Northern Ireland
• Adam Wilson and Sons Ltd
• Northern Ireland Forest Service
• Highland Birchwoods Ltd

Project people

• Shaun Mochan, Project leader, Forest Research.
• Prof. Barry Gardiner, Programme Leader and Deputy Head of Division, Forest Management Division, Forest Research.
• Elspeth Macdonald, Project Leader, Forest Research.
• Dr. Alexis Achim,  Laval University, Quebec City, Canada
• Dr. John Moore - SIRT Programme Leader, Centre for Timber Engineering
• Dr. Adrian Hapca -  Centre for Timber Engineering
• Sven-Olof Lundqvist - STFI-Packforsk (Stockholm, Sweden)
• Mauro Sonegro - www.staff@biovision.it