Scots pine timber quality in North Scotland: market requirements and resource availability

 

Summary

Scots pine forest

Scots pine is the only timber-producing conifer that is native to Scotland . As such it plays a key role in delivering a wide range of benefits to the rural economy, including sustainable timber, landscape enhancement, wildlife habitats, opportunities for recreation and community involvement. Almost 80% of the total area of Scots pine high forest in Scotland lies in the Highland and Grampian conservancy areas. Timber production from these forests is forecast to continue increasing over the next 15 years.
 
A number of recent initiatives and projects have considered the utilisation of Scots pine timber and its contribution to sustainable rural development. These include publications by Worrell and Ross (2004) and Davies et al. (2001), the work of the Forest of Spey and Deeside Forest management groups, timber evaluation and grading by the Building Research Establishment (BRE) and a major conference in October 2004 on “Scots Pine and Rural Development”, organised by Forestry Commission Scotland and the Forest of Spey partnership.

This project, which is part of the silviculture and timber properties research programme, seeks to address industry requirements as identified in previous work and to link to ongoing initiatives (e.g. BRE projects on machine grade settings for Scots pine and re-engineering). The current utilisation of Scots pine and available markets will be analysed. Tools will be developed to consistently assess Scots pine timber quality and facilitate the targeting of material to the most appropriate end-use. Information about the quantity and quality of the Scots pine resource, that will inform the wood-processing industry’s investment decisions, will be provided.

Detailed objectives

To provide information to the forestry and wood-using industries about the quantity and quality of the Scots pine resource with reference to current and potential end-uses and markets

To increase the value to the rural economy of the Scots pine resource by evaluating the potential for utilisation in higher value end-products and identifying opportunities for adding value locally.

Forestry Commission policy

Timber is one of the key themes of the Scottish Forestry Strategy. By developing methods for assessing Scots pine timber quality and undertaking strategic surveys, this project will contribute to several of the requirements identified to promote predictable and stable timber supplies, namely:

• To institute a production forecasting initiative to explore how best to sustain consistent long-term timber supplies, and to clarify likely levels of production and wood quality
• To promote development of the quality and diversity of the timber resource by the full range of existing and potential markets
• To encourage the production of high quality timber.

In addition a market development study will contribute to the aim of encouraging more use of timber.

Methods and preliminary results

The project comprises four tasks:

• Analysis of current utilisation of Scots pine
• Development and testing of timber quality assessment methods
• Assessment of the end-use quality of standing Scots pine
• Market development study

Analysis of current utilisation of Scots pine

This part of the project comprised an analysis of Scots pine timber harvested in North Scotland, considering where it was processed, end-uses and the timber quality requirements for different markets.

Questionnaires regarding Scots pine management, harvesting, processing and product manufacture were distributed to growers, processors and end-users in March 2006. Visits to end-users supplemented questionnaire responses.

The full report can be downloaded below. The key findings of the survey were:

• Responses from forest owners/growers covered 57,766 ha of Scots pine forests, 53% of the area of Scots pine forest reported in the National Inventory of Woodlands.
• Results of the growers’ questionnaire indicated that the average age of 1st thinning for Scots pine was 30 years, that the split between clearfell and Continuous Cover Forestry (CCF) was 43%:57% and that the average age at clearfell was 62 years.
• Respondents to the growers’ questionnaire reported that just under 207000 m³ of Scots pine timber was harvested during 2005. This compares to 325600 m³ reported as having been processed in the processors’ questionnaire and the forecast availability for the study area of 505000m3.
• 50% of the timber harvested was processed into panel board products, with a further 40% processed for agricultural and domestic fencing.
• 60% of the volume of Scots pine sawn timber and timber products was sold through timber merchants, builders’ merchants and DIY chains.
• Key timber quality criteria for Scots pine logs were identified by growers and processors as bluestain, straightness, knottiness and size. Ovality, taper and crop uniformity were also judged to be important.
• Concerns about quality were focused on variability and the inability to predict internal characteristics. Black knots were seen as a major defect. Task 2 of this project is aimed at developing techniques to assess timber quality in standing trees.

 Market Requirements and Resource Availability report ^(PDF-482K)

Development and testing of timber quality assessment methods

Three sample stands were studied to evaluate the potential of a number of non-destructive timber quality assessment methods (stem straightness score, various branching assessments, standing tree and log acoustic tools) for prediction of log grade out-turn, sawn timber mechanical properties and appearance grade.

Stem straightness score and height of lowest dead branch were found to be the best measurements for predicting green log yield. A model predicting sawn timber stiffness from HM200 log acoustic measurements was developed and logistic regression analysis is being used to suggest threshold HM200 values for different machine grade strength classes.  Sawn timber stiffness was weakly correlated with ST300 standing tree acoustic measurements and with various branching measurements, at an individual tree level. Further data analysis is ongoing and a full report will be available during 2008.

Assessment of the end-use quality of the standing Scots pine

The objective of this work is to undertake a strategic assessment of the end-use properties of the standing Scots pine resource in North Scotland, using the assessment methods tested in Task 2, i.e. stem straightness score, height of lowest dead branch and acoustic assessment in standing trees and logs.

Two approaches will be used:

• A survey of Scots pine stands in Grampian and Highland, targeted on stands likely to be harvested before 2030 will be undertaken.
  
  This will provide assessment of timber quality of Scots pine likely to be marketed in next 20 years. Data will be analysed to quantify the effects of site conditions and silviculture on timber quality.
• Acoustic assessment of logs from across north Scotland.
  
  In south Scotland the HM200 log acoustic tool has been used to start mapping resource characteristics of Sitka spruce. A similar exercise will be undertaken in north Scotland for Scots pine, assessing a sample of logs in the sawmill and linking data to site location and stand characteristics. This work will be ongoing until spring 2009.

Market development study

A market development study evaluating potential new market opportunities for Scots pine timber was commissioned from Napier University CTE and conducted by Ivor Davies. Thirteen products were assessed against a number of technical and commercial criteria to identify those with the greatest potential for value added market development. The products highlighted were massive wood construction (Brettstappel), external cladding, garden and landscaping products (focused on the potential for wood modification by chemical or thermal treatment), playground equipment and stress laminated timber bridges.

 Market development study report ^(PDF-823K)

Northern Periphery Programme Project – “Developing the Pinus sylvestris resource”

Forest Research is participating in this collaborative project which involves partners in Scotland, Finland, Norway and Sweden, with the aim of stimulating the development and utilisation of Scots pine timber as a basis for supporting sustainable rural enterprises. The project, which is led by Highland Birchwoods will run from 2008 – 2011. Forest Research’s activities within the project are focused on timber quality assessment methodologies, modelling and forecasting quality and best practice guidance for silviculture to grow quality timber.

Further details about the "Developing the Pinus sylvestris resource" project.

Status

The project started in January 2006 and will continue until March 2009.

Project funders, partners, management and people

Contact

For further information contact:
 
Elspeth Macdonald
Forest Management Division
Forest Research
Forestry Commission
Woodlands
Fodderty Way
Dingwall, Ross-shire
IV15 9XB

Tel: +44 (0)1349 862144
Fax: +44 (0)1349 866624
Email: elspeth.macdonald@forestry.gsi.gov.uk

References

Davies, I., Pendlebury, J. and Worrell, R. (2001) Prospects for Native Timber Utilisation in the Scottish Highlands: a discussion document. Highland Birchwoods, Scotland

Worrell, R. and Ross, I. (2004) Growing Scots pine for high quality timber (2nd Edition). Cairngorms National Park Authority, Grantown-on-Spey, Scotland.

About this project

Project funders

• Forestry Commission
• Forestry Commission Scotland
• Highlands and Islands Enterprise
• Scottish Enterprise

Project partners

• BRE
• Centre for Timber Engineering, Napier University
• James Jones & Sons Ltd
• Forest Enterprise Scotland
• Seafield Estate
• Cawdor Forestry

Project management

The project is being led and delivered by Forest Research, reporting to the funding partners. A small project steering group has been established to oversee and guide the project, ensuring it remains relevant to industry needs and that the results are effectively communicated.

Presentations to Project Steering Group meeting, 27th June 2007:

• Developing markets for Scots pine ^(PDF-278K)
• Maximising the potential of Scots pine falling boards ^(PDF-630K)
• New machine settings for higher strength classes for UK grown Scots pine ^(PDF-207K)
• Scots pine market development study ^(PDF-1181K)

Presentations to Project Steering Group meeting, 12th February 2008:

• Better utilisation of Scots pine ^(PDF-819K)
• Developing the Scots pine resource ^(PDF-917K)
• Predicting log grade recovery in Scots pine ^(PDF-1463K)
• Proposed survey of Scots pine timber quality ^(PDF-465K)
• Scots pine market development study ^(PDF-1639K)
• Scots pine timber quality assessment methods ^(PDF-1312K)

In addition to the project steering group the project team will make regular progress reports to the Grampian and Highland Regional Forestry Forums.

Project people

• Elspeth Macdonald, Project Leader, Forest Research
• Barry Gardiner, Programme Leader Timber Properties, Forest Research
• John Fonweban, Timber Properties Modeller, Forest Research
• Dave Auty, PhD Student, Aberdeen University and Forest Research 
• Geoff Cooper, Senior Consultant, Building Research Establishment
• Chris Holland, Senior Consultant, Building Research Establishment