A Fort Nelson value added plant tries a new approach to harvesting aspen, with a goal of significantly improving spruce understory retention.

By Jim Stirling
Copyright 1996. Contact publisher for permission to use.

A processor/forwarder harvesting system will be tested near Fort Nelson, BC this winter to examine if dominant aspen can be removed without excessive damage to spruce understory. The processor/forwarder technique is one of two operational trials planned by the Canadian Chopstick Manufacturing Co.Ltd., a Japanese-owned company that uses only top-notch aspen in its Fort Nelson manufacturing plant. The other trial will use a modified strip shelterwood system with a feller buncher and grapple skidder.

CCMC has conducted earlier trials designed to leave spruce understory to increase biodiversity, improve wildlife habitat and enhance visual quality values. The company is continuing to consult and co-operate with the Ministry of Forests to see if their ministerial guidelines are achievable.

`Logging costs on our trials have increased from 23% to 35% depending on the logging technique. During the next three years we will learn if we can achieve the goals required by the ministry,'' summarizes Frank Senko, CCMC's woodlands manager.

The Ministry of Forest's guidelines for a two species forest call for understory retention on sites with 400 to 700 spruce stems per hectare requiring at least 40% to remain undamaged.

The trials are taking place on research blocks of 20-25 hectares with a comparable level of understory. For trail one, CCMC's contractor J.P. Logging Ltd., has acquired a Pierce HTH Bigwood processing head to be matched with a Cat 330 carrier. The operational plan is to direct fall and process aspen at right angles or not more than 30 degrees to the edge of skid trails. The trails will be a maximum five metres wide and positioned 20 metres apart.That way the aspen can be felled into openings or where the understory is less dense. Tops are to be uniformly spread for the harvesting machines to walk on and leave ample wood debris.

The Bigwood processor was selected for a variety of reasons, says John Peachey, of J. P. Logging. The aspen grows in a wide range of diameters from 15 centimetres to 76 centimetres.

Aspen is heavy - around 900 kilograms per cubic metre - and it is very limby. ``What little you trade off in speed in agility you gain with the ability to handle the big wood,'' says Peachey. The Bigwood processing head lives up to its name and weighs about 4,218 kilograms. ``Smaller heads wouldn't stand up. One of the biggest reasons I bought it is because I believe we're going to see more processing in the bush and forwarding,'' says Peachey. He was looking forward to the trial. ``I think with the processor and the forwarder we can have the aspen sorted and decked on a good surface with hopefully little extra costs.'' He notes Pierce Pacfic have been very supportive with their service back-up on the Bigwood which was promising great availability.

The approximately 7.6 metre reach of the 330 is additionally useful for understory retention, adds operator Terry Krell. He says the 100 centimetre chain saw bar is more than adequate for a 76 centimetre diameter tree. The Bigwood/330 combo allows the hydraulic pressure to remain even making it easier on the machine and reducing maintenance, he notes.

A Timbco TF 815 15-tonne forwarder was earmarkedto complement the Pierce processor. The forwarders frame was to be extended to handle the 9.7 metre long residue aspen stems. Chopstick grade material was to be processed in 4.8 and 2.4 metre lengths. the trial's commitment to reduction of road systems will result in less soil compaction and degradation, of immense importance in today's harvesting operations.

J.P.Logging will also operate a conventional road side show on a control block. The emphasis there, too, will be on understory retention.

The second research block will see a modified pattern of trials undertaken in mixed forests in Alberta. Skid trails five metres wide and 15 metres apart will be used by both a feller buncher and a grapple skidder. The buncher will fill the trails, the skidder will remove the felled timber to roadside. The buncher will then return for the remainder of the merchantable timber in a single pass. Rub posts are envisioned to protect residual understory. However, CCMC anticipates some compaction on the skid trails causing aspen regeneration problems and shade from the spruce understory is unfavorable for aspen re-generation.