Using wood wisely

I didn’t see a monster on my visit to Loch Ness but I did end up learning something about forestry and how the use of timber can be maximised. I’d travelled to a forestry site called Glen Brien, close to the southern end of the Loch, where 73 hectares (180 acres) of Lodgepole pine (Pinus contorta) and Sitka spruce (Picea sitchensis) were being felled to be turned into OSB (oriented strand board) by Norbord. The company has a long term contract with the Forestry Commission to harvest 120,000 tonnes of timber per year – the site at Glen Brien represents 16,000 tonnes, that’s 60,000 trees.

The operation is impressive. It will take two harvesters five to six months to clear the site. Each costs £200,000 – £300,000 and they’re complemented by two £225,000 ‘forwarders’ which gather and load the sawn logs ready for transportation to Norbord’s OSB plant in Inverness. Despite this highly mechanised operation, the emphasis is on being sensitive to the environment. Forestry is a future looking business – the trees being felled are around 45 years old and a five to seven year thinning rotation will have been carried out; once cleared the land is left to lie fallow for two to five years. 

Compaction of the soil is a big concern. Interestingly the brush shaved from the trees is spread across the site to protect the ground. In addition, the harvesters and forwarders have extra wide tracks to distribute their weight and every effort is made to avoid crossing the site unnecessarily. A big concern is preventing mud reaching the watercourses that cross Glen Brien and the team that work there have extensive training in silt control and dealing with oil spills.

Used in everything from site hoardings to the construction of timber framed homes, OSB is a ubiquitous material and Norbord is the third biggest OSB producer in the world. The manufacture of OSB makes good use of the timber harvested.

Waste wood is used for biomass with Norbord claiming to be the largest generator of biomass heat energy in the UK. The company believes burning virgin wood fibre should be a choice of last resort and, with this in mind, is behind the Let’s Use Wood Wisely campaign which lays out a clear hierarchy for the use of timber. After first use, timber should be reused, then recycled and only then, after many decades of use, recovered and burn as fuel. The campaign states: “Burning any of Britain’s wood for electricity is wasteful when it could be used instead to make products for homes and industry and in the process lock up CO2 for decades.”

Images and video: ©Roger Hunt