How can chopping down trees for construction be good for the environment? The answer is in the difference between deforestation and modern sustainable forestry. And if we get it right, the positive impacts of sustainably managed production forestry in the UK will extend far beyond the shores of our islands.
Timber demand and net zero
Most of us understand the concept of photosynthesis, the process by which trees and plants take in carbon dioxide and turn it into oxygen, effectively reversing some of the negative impacts of our carbon-emitting industrialised society. The carbon dioxide is stored or sequestered in a tree’s trunk and branches, so it makes sense to plant more trees and sequester more carbon dioxide.
However, we also understand that using timber in place of carbon-heavy materials such as concrete and steel is good for the environment too. We’re locking that carbon dioxide sequestered by the tree into a building or structure, with the carbon only re-released when the timber is burned or rots away – hopefully after a number of re-uses – making it effectively a carbon neutral, or carbon positive material.
Demand for timber in the developed and developing world is rising, with new uses for timber accelerating that increase, not least because so many economies see the deployment of timber as a vital weapon in the battle to reach net zero. Asset manager Gresham House, which specialises in forestry investment, forecasts that global timber consumption will rise by 170% over the next 30 years.
In the UK, demand for hardwoods in rose by 26% in 2021, softwoods by 21% and plywood by 13% compared to 2020, according to Timber Development UK. Last year also saw record volumes of timber imported into the UK, 11.7 million m3, according to the Timber Trade Federation (TTF).
According to the Environmental Audit Committee, which scrutinises Government policies and performance on environmental protection and sustainable development, we are the world’s second highest importer of timber. Over 80% of our timber is imported and one-fifth of that comes from countries whose forestry practices involve high environmental or social risks. The Committee has launched an inquiry into the impact of increased timber use on global deforestation.
At 13%, the proportion of the UK’s land area taken up by forest is around a third of the European average, and far less than countries such as Finland and Sweden which have around 70%. The UK has around 3.24 million hectares of woodland, split almost equally between broadleaf – trees without needles, often deciduous - and conifer woodlands. Of that, 1.32 million hectares is in England, 1.49 in Scotland, 0.31 in Wales and 0.12 in Northern Ireland.
It may be surprising to learn that none of our woodland is classed as truly natural. However, 650 000 hectares are classed as semi-natural woodland and of these 340,000 hectares are deemed ancient semi-natural woodlands (ANSWs). These date back to 1600 in England and 1750 in Scotland and mostly consist of broadleaf species although Scotland’s native pine forests in the Highlands are ANSWs.
The Industrial Revolution in the 18th century was responsible for eating up much of our wooded areas. At the time of World War I, just 5% of the UK’s land area was woodland. With timber imports compromised by war, the Government of the time realised it needed to plant more trees and through state planting and incentivisation, hectares of new forests, mainly conifers, were created on low-value agricultural land.
Around one-third of the UK’s woodland areas are publicly owned by organisations such as Forestry England and Forestry and Land Scotland, with two-thirds in the hands of farmers, family trusts, charitable trusts, local groups and companies. Many woodland areas are tiny with an estimated 60,000 woodlands part of farm estates, 50,000 of them less than 10 hectares.
The UK forestry industry is made up of a mix of businesses, including successful family owned and world leading companies that practice sustainable forestry and deal in certified wood products. All offer local employment across rural UK.
Timber production is just one of the benefits that UK woodlands provide to local communities and businesses. Today, they are home to a range of outdoor sports and activities; community and educational facilities; flood protection; conservation and woodland biodiversity; and connected rural businesses.
It is conifer forests that are generally the most productive, with timber used for a variety of essential purposes ranging from construction through to pallet wood, packaging and fuel wood. The conifer species planted in UK forests generally take 30 or 40 years to mature, at which point they will be harvested and replaced.
It is essential to note that productive forests are managed to increase biodiversity as outlined in the Biodiversity, Forestry and Wood report from Confor. Importantly, with the adoption of the UK Forestry Standard, planting and replanting no longer tends to follow the rigid plantation-style lines of the post-war forests. Instead, trees are planted to follow and enhance natural features such as water courses and ridges. Harvesting of existing forests is managed to restructure forests to create greater age diversity and increase diversity of habitats. In addition, a variety of tree species are planted in the right place for the right reason – not all of which will be used for timber – leading to further increased biodiversity.
There are a few smaller, mixed woodlands which are also productive. Here, felling is small-scale, almost bespoke, with trees selected and harvested to suit their end purpose.
One of the earliest definitions of sustainable forest management came from the Second Ministerial Conference on the Protection of Forests in Europe, held in Helsinki in 1993:
‘The stewardship and use of forests and forest lands in a way, and at a rate, that maintains their biodiversity, productivity, regeneration capacity, vitality and their potential to fulfil, now and in the future, relevant ecological, economic and social functions, at local, national, and global levels, and that does not cause damage to other ecosystems.’
That definition still makes sense today, with sustainable forest management seeking to balance environmental, economic and social benefits.
There are two main global certification schemes for sustainable forests: the FSC (Forest Stewardship Council) and the PEFC (Programme for the Endorsement of Forest Certification) which were set up in 1993 and 1999 respectively. Both have two components, certifying forest management practices and the supply chain or ‘chain of custody’.
FSC sets its own principles for forest management, with any local standards having to conform to those principles. PEFC, on the other hand, is an umbrella body that endorses individual forest certification schemes. There are around 50 different national certification programmes, many of which fall under that PEFC umbrella.
The UK Woodland Assurance Standard (UKWAS) is based on the requirements of FSC and PEFC, as well as the UK Forest Standard, a new version of which is currently out for consultation.
Globally the percentage of forests that are certified as sustainable is around 10%. In the UK, around 44% or 1.42 million hectares is certified.
Given that our demand for timber is forecast to grow significantly, it seems sensible that our national strategy should be to plant more sustainably managed productive forests. And that is something that the UK Government has committed to doing. In 2019, it pledged to plant 30,000 hectares of new woodland every year by 2024.
However, official statistics released in June this year  showed that we are not on track to hit those targets. In the 12 months to March 2022, the UK planted less than 14,000 hectares of woodland, with Scotland contributing three-quarters or 10,480 hectares of that total. England planted 2,260 hectares, Wales 580 and Northern Ireland 540.
One of the things that the Environmental Audit Committee will be pushing for is a robust forecast of the UK’s demand for timber over the coming decade, with a tree planting and timber production plan that makes sense with that level of demand – without further contributing to the global deforestation catastrophe.
The chair of that committee, MP Philip Dunne, summarises the UK’s challenge perfectly:
“We must make sure the domestic timber industry is fit for the future and can support our net zero ambitions, while better understanding the impact any imports have on the wider world.”