'TREE-LISTENING' TECHNOLOGY TO BE SHOWCASED AT TOP SCIENCE EXHIBITION (22/06/07)

Forestry scientists have been "listening to the trees" to improve business efficiency and reduce environmental impacts in the UK's wood supply chain.

And they will showcase this innovative acoustic technology at this year's prestigious Summer Science Exhibition in London, hosted by the Royal Society. (2 - 5 July 2007)

The researchers are from Forest Research (the scientific research agency of the Forestry Commission), working in partnership with Edinburgh's Napier University, Glasgow University, Canada's Laval University, and New Zealand company Fibregen.

They have discovered that they can assess the quality of timber by monitoring and interpreting the behaviour of sound waves transmitted through a log or a standing tree trunk. Features such as wood density, knots, grain angle and fractures can affect the time the signal takes to travel through the log.

In practical forestry terms, this means that a decision can be made in the forest about which customer will receive each consignment of logs.
The logs with the stiffest wood can be sent to sawmills for processing into products requiring high strength, straightness and stiffness, such as construction timber, while other logs can be directed to uses such as those requiring pulp and chips.

Currently, logs undergo a comparatively unsophisticated visual assessment in the forest and are divided into two categories: "red" and "green" logs, for dispatch to suitable customers. More-sophisticated tests can only be made after the logs have arrived at the sawmill, and unacceptable logs might have to be reloaded on to lorries for a second journey, to another processing mill. This consumes time, money and resources, and contributes to greenhouse gas emissions and other environmental impacts associated with heavy road transport.

The acoustic technology takes two forms. In one, a felled log can be tested by tapping the end with a hammer and using a sensing instrument pressed against the end of the log to measure the time the sound wave takes to travel through it. The sound wave can be converted by the equipment into an assessment of the wood's characteristics, such as stiffness and potential strength.

In the other, two parts of an acoustic instrument can be attached to a standing tree trunk and a signal sent through the trunk from one part to the other. The speed of the signal can be measured and provides similar timber-quality information.

Forest Research staff have just completed six months working with sawmiller James Jones & Sons Ltd to test and develop prototype wood supply-chain systems that incorporate this technology, and they are about to start a programme of training events to roll it out to the whole British forestry industry.

Ultimately, the technology will be incorporated into the sawing "heads" of the harvesting machines that fell trees in commercial forests. This means the machine operators will become one-stop shops not only for felling, measuring, trimming and sawing the logs into the lengths required by customers, as they do now, but also for assessing their timber quality and sorting them for despatch to the most appropriate customer.

Professor Barry Gardiner of Forest Research's forest management division said,

"We're thrilled to be have an opportunity to demonstrate this exciting technology at the Royal Society's Summer Science Exhibition.

"It's a superb example of how modern technology can not only increase the business competitiveness of our forest and timber industries, but also reduce the environmental impacts and enhance the sustainability of British forestry.

"Timber is a globally traded commodity and its price is set by the world market, so the UK's timber growers have to compete on price with imports from lower-cost economies. Technological developments such as this can help them to remain competitive."

The Royal Society's Summer Science Exhibition is held annually at the Royal Society, the UK's national academy of science. Admission is free and the exhibition is open to the public. This year, 23 interactive exhibits will be on show presenting the best of UK science, engineering and technology. During the four days of the event, more than 4000 people are expected to take up the opportunity to explore the exhibition. For more information go to www.summerscience.org.uk.

Further information about Forest Research's timber properties research programme is available by visiting www.forestresearch.gov.uk or by contacting Barry Gardiner at barry.gardiner@forestry.gsi.gov.uk, telephone 0131 445 6950.