Spruce almighty - major Sitka spruce research report published

Wood Focus magazine
2 Sep 2011
spruce branch

A research report that summarises everything known about Sitka spruce and brings together 90 years of research into a single document has been published by the UK’s Forestry Commission (FC).

The report, Wood properties and uses of Sitka spruce in Britain, aims to centralise previously scattered knowledge about the species and explores three main areas – how it got introduced to Britain from North America, its properties and an overview of end products that are or could be made from the wood.

Originally found in the Pacific Northwest region in places such as Washington, Oregon and British Columbia, the tree was mainly used by Native Americans to make baskets, hats and canoes, with Douglas fir the wood of choice for making buildings in those areas. It was not until the early 1900s that Sitka spruce found more widespread use, when its high specific strength and stiffness made it invaluable in manufacturing WWI and WWII airplanes and prompted its widespread introduction to Britain.

‘It grows incredibly well in the UK because of our mild and moist climate and similar latitude,’ says Barry Gardiner – Programme Group Manager, Centre for Forest Resources and Management at the FC. ‘It can grow tall even in bad soil, outgrows pretty much any other conifer, is extremely resistant to disease, and produces a wood that is strong for its weight.’

The Sitka spruce is now the main conifer grown in Britain and is a major part of the commercial wood products industry, which is why Gardiner heralds the report as timely. Inspired by a model used in New Zealand to chart the history of radiata pine and Douglas fir, the report draws together information from a wide range of sources, including previously unpublished documents that were just ‘sitting in box files on someone’s desk’ at the FC, BRE, and the Princes Risborough laboratories.

Much of the report draws on information that is already in existence, but hidden. ‘A lot of “grey” literature already existed in files that were not available to people. Often very obscure reports had been commissioned in the past but were difficult to access. The kind of files where the paper was beginning to fall apart.’

‘Some of it may have been available in scientific journals but that’s not a very good place for someone like an architect or an engineer to access the information.’

The FC tasked John Moore from Napier University in Edinburgh, UK, with collating all of the information and rewriting it as one manageable, easy to access report over the course of a couple of years. Surprisingly, they found that the older material didn’t need much amending to fit in line with more recent research. ‘We were able to cross-check more recent measurements with the older measurements,’ says Gardiner, who claims the report acts as a good marker of the development of wood science as a field, and a testament to the skills of earlier technicians.

‘We’ve been able to carry out work with newer techniques and maybe more rigorously than they were able to do, but we haven’t found anything that contradicted what our colleagues in the 50s and 60s found. When you find earlier work that confirms what you’ve just done it gives you a lot of confidence in what you are saying.’

He adds, ‘the old files can be left to crumble now – we have taken the information from them and now people can download it.’

Gardiner hopes that in an ideal world, there will be a collection of similar reports on all different species for engineers and architects alike. ‘Maybe in five years’ time they could also have Scots pine, Douglas fir and larch all sitting there as well. It would also be wonderful if we could have a series of the key conifer species.’