David Sulman, of the Confederation of Forest Industries (Confor), discusses the case for recovering more bark from UK harvesting operations.

When people think of forest products, many may not think of bark, which is a significant product in its own right, together with sawn timber, sawdust and wood chips. The processing of bark represents a major and integral part of the UK wood supply chain, with more than 1 million tonnes of bark processed in the UK every year.

It is perhaps all too easy to take this remarkable material for granted, but we should think again; bark products meet the needs of a wide range of markets, including mulches, growing media, play surfaces, soil improvers and equestrian surfaces, to name but a few. With the drive to reduce the use of peat in horticulture, there is growing awareness that bark offer a sustainable alternative. Independent certification and endorsement ofsome bark products is also available.

Bark not only provides a vital function for the growing tree, but also provides a very versatile product after felling and processing. Demand for bark in the UK is outstripping the domestic supply, with the consequence that there is a reliance on imports to meet demand.

What’s wrong with that you may ask? One particularly timely response is that continued bark imports pose an increased risk of the entry of tree pests and diseases, despite plant health controls. Is all imported woody material appropriately controlled, let alone inspected? Is reliance
on documentary evidence, (plant passports etc), a realistic or robust defence?

At a time when there is increasing focus and concern about tree pests and diseases, there is growing concern that bark imports could provide an unwelcome pathway for the introduction of harmful insects and diseases into the UK, which could have very damaging effects on our trees, woodlands and forests, as well as on all of those who depend on them for a living. We only need to look at the devastating damage being done by tree pests to Larch, Pine, Ash and Oak in the UK. There is a seemingly never-ending list of tree pest and disease threats and there is absolutely no room for complacency.

The recent discovery of Ips typographus, the Eight-toothed Spruce Bark Beetle, in Kent must serve as a ‘wake-up call’. It is hoped that the legislative and practical measures taken to tackle this outbreak will result in its successful eradication. The discovery of this very dangerous tree pest is a stark warning of how vulnerable we are to imported tree pests; it has been suggested that the colony may have been active for a couple of years and that adult beetles may have been blown across the Channel. This seems very likely, as there are very well established populations of this beetle on the Continent. A key question to consider is how realistic is it to expect the UK to remain freefrom this pest?

Some would say that if we want to reduce our exposure to tree pests and diseases, we should ban imports of a range of wood and wood products; experience has shown that officialdom is generally not in favour of such moves, unless there are exceptional circumstances, for fear of retaliatory action by trading partners.

Many believe that there is real potential to increase bark supply from our current operations in the UK; so what could be done?

We should start by considering what can be done during harvesting; for example by encouraging harvester operators and contractors to adapt their practice to minimise bark loss during mechanised harvesting. Keeping more bark on the log, as well as reducing log damage, has other benefits, including limiting drying out and improving recovery in the sawmill.

Improved harvesting practice could include reducing the number of passes through the harvester head, more appropriate feed roller pressures, ensuring knives are well maintained, (preferably with a negative angle), and the use of less aggressive feed rollers, which although more expensive than ‘standard’ feed rollers, those with rubber elements can also help reduce wear and tear on the head, because of the shock absorbing effect. It is also acknowledged that seasonal effects can also impact on bark loss during harvesting.

Graham Andrews, a Director of TMA Bark, one of the UK’s largest bark processors, said “I fully support the initiative to recover more bark from UK harvesting operations. Demand for bark is increasing and encouragingly, customers are becoming better informed about bark quality matters. In addition, there are growth opportunities in the market, so now is the time to think seriously about what we can do”.

Anecdotal evidence suggests that bark loss during harvesting may be more severe in the southern half of the country.

There’s also a commercial benefit too, as better bark fetches better prices and if we can produce more bark in the UK, we can reduce our reliance on bark imports, so it could be win, win. We need more UK- produced bark – now’s the time to give this serious consideration

David Sulman of Confor said, “I believe that there is a compelling case for maximising bark recovery from UK timber harvesting operations and hope that increased volumes can be recovered. I would welcome readers’ thoughts on this matter. There is undoubtedly an opportunity to make a difference, which has the potential to benefit us all”.

Confederation of Forest Industries, Office 14, John Player Building, Stirling Enterprise Park, Springbank Road, Stirling, FK7 7RP.

Tel: 01786 449029