Tag: forests

What is biomass?

21 August 2020

Sustainable bioenergy
Illustration of a working forest supplying biomass

What is biomass?

In ecological terms, biomass refers to any type of organic matter. When it comes to energy, biomass is any organic matter that can be used to generate energy, for example wood, forest residues or plant materials.

How is biomass used?  

Biomass used and combusted for energy can come in a number of different forms, ranging from compressed wood pellets – which are used in power stations that have upgraded from coal – to biogas and biofuels, a liquid fuel that can be used to replace fossil fuels in transport.

The term biomass also refers to any type of organic material used for energy in domestic settings, for example wood burned in wood stoves and wood pellets used in domestic biomass boilers.

Biomass is organic matter like wood, forest residues or plant material, that is used to generate energy.

Where does biomass come from?

Biomass can be produced from different sources including agricultural or forestry residues, dedicated energy crops or waste products such as uneaten food.

Drax Power Station uses compressed wood pellets sourced from sustainably managed working forests in the US, Canada, Europe and Brazil, and are largely made up of low-grade wood produced as a byproduct of the production and processing of higher value wood products, like lumber and furniture.

Biomass producers and users must meet a range of stringent measures for their biomass to be certified as sustainable and responsibly sourced.

Key biomass facts

Is biomass renewable?

 Biomass grown through sustainable means is classified as a renewable source of energy because of the process of its growth. As biomass comes from organic, living matter, it grows naturally, absorbing carbon dioxide (CO2) from the atmosphere in the process.

It means when biomass is combusted as a source of energy – for example for heat or electricity production – the CO2 released is offset by the amount of CO2 it absorbed from the atmosphere while it was growing.

Fast facts

  • In 2019 biomass accounted for 6% of Great Britain’s electricity generation, more than 1/6 of the total generation of all renewable sources
  • There is about 550 gigatonnes of biomass carbon on Earth in total. Humans make up around 1/10,000th of that mass.
  • Modern biomass was first developed as an alternative for oil after its price spiked as a result of the 1973 Yom Kippur War
  • The International Energy Agency (IEA) estimates bioenergy accounts for roughly 1/10th of the world’s total energy supply

Biomass is a renewable, sustainable form of energy used around the world.

How long has biomass been used as a source of energy?

Biomass has been used as a source of energy for as long as humans have been creating fire. Early humans using wood, plants or animal dung to make fire were all creating biomass energy.

Today biomass in the form of wood and wood products remains a widely used energy source for many countries around the world – both for domestic consumption and at grid scale through power stations, where it’s often used to replace fossil fuels with much higher lifecycle carbon emissions.

Drax Power Station has been using compressed wood pellets (a form of biomass) since 2003, when it began research and development work co-firing it with coal. It fully converted its first full generating unit to run only on compressed wood pellets in 2013, lowering the carbon footprint of the electricity it produced by more than 80% across the renewable fuel’s lifecycle. Today the power station runs mostly on sustainable biomass.

Go deeper

Read next: What is reforestation and afforestation?

What is reforestation and afforestation?

Sustainable bioenergy
Reforestation and afforestation

What is reforestation and afforestation?

Reforestation is the process of planting trees in a forest where the number of trees has been decreasing.

Afforestation is when new trees are planted or seeds are sown in an area where there were no trees before, creating a new forest.

Why carry out reforestation and afforestation?

Reforestation and afforestation are two of the leading nature-based solutions for tackling the effects of climate change. For commercial foresters and landowners, these two practices are essential to ensuring they can grow wood for wood products and continuously meet demand in a sustainable way.

Reforestation is crucial in combating or preventing deforestation or forest degradation, where forests shrink in size or are completely removed. As well as reducing a forest’s ability to absorb carbon dioxide (CO2), deforestation can destroy wildlife habitats and contribute to the likelihood of flooding in certain areas.

Afforestation can also help avoid desertification, where fertile land turns into a desert as a result of drought or intensive agriculture.

Reforestation is the process of planting native trees in a forest where the number of trees has been decreasing.

How does reforestation and afforestation limit the effects of climate change?

Forests are a natural way of keeping the earth’s CO2 levels in check. The more trees there are, the more CO2 is captured and converted into oxygen through photosynthesis.

By absorbing CO2, forests help to lower the amount of greenhouse gasses in the atmosphere and reduce the effects of climate change.

Reforestation and afforestation help maximize these abilities of forests by increasing the overall amount of forested land on the planet.

Key forest facts

Did you know?

Different types of forests, such as tropical, swamps or mangroves, all absorb CO2 at different rates.

The age of a forest also impacts absorption. Young, rapidly growing, trees absorb CO2 at a faster rate than more mature ones, which have large amounts of carbon locked in already.

Afforestation is when new trees are planted or seeds are sown in an area where there were no trees before.

What roles does reforestation play in commercial forestry?

The global wood products industry depends on sustainable forests to supply the wood needed to make furniture, create construction materials and provide fuel for energy.

The supply chain will often start with what’s called a ‘working forest’ – a commercially-run forest which is often privately owned. The landowner will grow a working forest to a certain stage of maturity and then harvest some or all of the trees to sell the wood. Once the wood has been sold for use as lumber, wood products or fuel, the landowner will reforest the areas to regrow the trees.

Foresters will typically do this in stages across their land to ensure there are multiple stands of forest at different stages of growth across their land, which ensures there is consistent, sustainable growth at all times.

Fast facts

Go deeper

Button: What is carbon capture?

The science making new discoveries in forests

22 July 2020

Sustainable bioenergy
Weyerhaeuser tree nursery in the US South

Scientific research isn’t all test tubes and lab coats – sometimes it’s bark and soil. It might be a world away from the image of a sterile laboratory, but the world of forestry is one that has seen significant scientific progress since the 18th century, when it first emerged as an area of study.

The development of environmental sciences and ecology, as well as advances in biology and chemistry mean there are still new discoveries being made – from trees’ ability to ‘talk’ to each other through underground fungi networks, to forests’ positive impact on mental health.

Fostering greater awareness and understanding of fragile forest ecosystems such as the cypress swamps of the Atchafalaya Basin in Louisiana, forestry has also allowed for the improvement of working forests — landscapes planted to grow wood for products and services that often avoid the use of fossil fuel-based alternatives.

Cypress forests in the Atchafalaya Basin in Louisiana are an example of a forest landscape where the suitable management practice is protection, preservation and monitoring

Cypress forests in the Atchafalaya Basin in Louisiana are an example of a forest landscape where the suitable management practice is protection, preservation and monitoring

By enhancing the genetic stock, tree breeding ensures seedlings and plants are better adapted to their environment (soil, water, temperature, nutrient level, etc.). Science can now help trees to grow more quickly, storing more carbon. It can also give trees better form — straighter trees can produce more saw-timber which can, in turn, lock more carbon in buildings made predominantly or partially of the natural, renewable product that wood is.

But more than just uncovering surprising insights into the ins and outs of our natural world, forestry science is contributing to a far bigger goal: tackling climate change.

The science of forests

When the scientific study of forests first emerged in 18th century Germany, it was with the aim of sustainability in mind. Industries were concerned forests wouldn’t be able to provide enough timber to meet demand, so research began into how to manage them responsibly.

Forestry today encompasses much more than just providing saw logs and the research going into it remains driven by the same goal: to ensure sustainability. Its breadth, however, has grown.

The UK Forestry Commission’s research and innovation strategy highlights the scope it should cover: “It must be forward-looking to anticipate long-term challenges, strategic to inform emerging policy issues, and technical to support new and more efficient forestry practices.”

Pine trees grown for planting in the forests of the US South where more carbon is stored and more wood inventory is grown each year than fibre is extracted for wood products such as biomass pellets

Being able to deliver on this breadth has relied on rapid advances in technology – including taking forestry research into space.

The technology teaching us about trees

As in almost every industry, one of the major drivers of change in forestry is data, and the ability to collect data from forests is getting more advanced.

At ground level, techniques like ‘sonic tomography’ allow foresters and researchers to ‘see’ inside trees using sound waves, measuring size, decay and overall health. This, in turn, offers a bigger picture of forests’ wellbeing.

At the other end of the scale, satellites and mapping technology are playing a major role in advancing a macro view of the world’s forests – particularly in how they change over time. As well as a potent tool in monitoring and helping fight deforestation, satellite images have revealed there is nine per cent more forest on earth than previously thought.

Space satellite with antenna and solar panels in space against the background of the earth. Image furnished by NASA.

The European Space Agency’s Earth Explorer programme will go a step further and use radar from satellites to penetrate the forest canopy, measuring tree trunks and branches rather than just the area covered by forest. Determining the volume of wood in forests around the planet will effectively enable researchers to ‘weigh’ the world’s forest biomass.

The masses of data these advances in tech are providing, is playing a major role in how we manage our forests, including how we can use them to fight global warming.

Taking on the climate crisis

Forests are one of the key defences against climate change – so much so they’re included in the Paris Agreement. Trees’ abilities to absorb carbon dioxide (CO2) has long been established knowledge. Thanks to what climate scientists call IAMs or integrated assessment models, we  now know how much they can extract from the atmosphere and how long they can continue to do so, as CO2 levels rise.

One optimistic hypothesis says trees will take in more CO2, as the levels rise. To test this, researchers in the UK are blasting controlled sections of a forest  with CO2 to increase its density by 40%, representing expected global levels by 2050. By tracking how trees react they hope to highlight the role they can play as carbon sinks.

Science also suggests they could not only help slow climate change, but actively fight it. The research considers that as well as absorbing CO2, trees are reported to emit gases that reflect sunlight back into space, ultimately contributing to global cooling.

However, planting more trees isn’t necessarily the only answer. In places experiencing drought such as the western US, thinning forests can reduce competition and allow healthier trees capable of absorbing more oxygen to flourish.

The increasing body of research on forests’ impact on climate change could prove vital in shaping both the forestry industry and national governments’ approaches forests. However, as a science, forestry could be considered to be in its infancy. At this crucial time for the planet’s future, forestry is becoming one of the most important environmental sciences, but a lot more attention, investment and research and development are required if we are able to fully understand and manage the world’s forest resources. We have barely scratched the surface.

Plant more forests and better manage them

22 June 2020

Sustainable bioenergy
Working forests in the US South

There is an ongoing debate about forests’ contribution to fighting the climate crisis.

Forests can act as substantial and effective tools for carbon sequestration during a high growth phase. They can also function as significant and extensive carbon storage areas during maturity and throughout multiple stages of the age class cycle, if managed effectively at a landscape level. Or, they can be emitters of carbon if over-harvested, subject to fire, storm, pest or disease damage.

Different age class forest stands in Louisiana

In a natural state, forests will go through each of these life phases: rapid early growth; maturity and senescence; damage, decay and destruction through natural causes. Then they begin the cycle again, absorbing and then emitting carbon dioxide (CO2) in a continual succession.

Recently, loud voices have argued against forest management per se; against harvesting for wood products in particular, suggesting that this reduces both forest carbon stocks and sequestration capacity.

Pine cut in into wood for different wood products markets in Louisiana. Big, thick, straight higher value sections go to sawmills and smaller and misshapen low-grade wood not suitable for timber production is sold to pulp, paper or wood pellet mills.

Many foresters consider that this is just not correct. In fact, the opposite is true. Research and evidence clearly support the foresters’ view. Active forest management, when carried out appropriately, actually increases the amount of carbon sequestered, ensures that carbon is stored in solid wood products, and provides substantial savings of fossil fuels by displacing other high carbon materials (e.g. concrete, steel, brick, plastic and coal).

Oliver et al.(2014)[1] compared the impact of forest harvesting and the use of wood products to substitute other high-carbon materials, concluding that: ‘More CO2 can be sequestered synergistically in the products or wood energy and landscape together than in the unharvested landscape. Harvesting sustainably at an optimum stand age will sequester more carbon in the combined products, wood energy, and forest than harvesting sustainably at other ages.’

This research demonstrated that an increase in the use of structural timber to displace concrete and steel could lead to substantial emissions savings compared to unharvested forest. The use of wood for energy is an essential component of this displacement process, although it is important to use appropriate feedstocks. Burning wood that could be used for structural timber will not lead to a positive climate impact.

The message here is to manage working forests for optimum sawlog production for long-life solid wood products and utilise the by-products for energy where this is the most viable market, this provides the best all-round climate benefit.

What happens when you close the gate

Closing the forest gate and stopping all harvesting and management is one option being championed by some climate change campaigners. There is certainly a vital role for the preservation and protection of forests globally: primary and virgin forests, intact landscapes, high biodiversity and high conservation value areas all need to be protected.

That doesn’t necessarily mean that there is no forest management. It should mean careful and appropriate management to maintain and ensure the future of the resource. In these cases, management is with an objective to reduce the risk of fire, pests and disease, rather than for timber production.

Globally, we need better governance, understanding and implementation of best practice to achieve this. Forest certification and timber tracing systems are a good start. This can equally apply to the many hundreds of millions of hectares of ‘working forest’ that do not fall into the protection categories; forests that have been managed for many hundreds of years for timber production and other purposes. Harvesting in these forests can be more active, but governance, controls and the development of best practice are required. Better management not less management.

During the 1970s there was a significant change of policy in the US, aimed at removing massive areas of publicly owned forest from active management – effectively closing the gate. The drivers behind this policy were well meaning; it was intended to protect and preserve the habitat of endangered species, but the unintended consequences have also had a substantial impact. In the 1970s little thought was given to the carbon sequestration and storage potential of forests and climate change was not at the top of the agenda.

The west coast of the US was most substantially affected by these changes, more than in the US South, but the data below looks at the example of Mississippi which is primarily ‘working forest’ and 88% in private ownership.

Pine trees in Mississippi working forest

This is the location of Drax’s Amite pellet mill. The charts below show an interesting comparison of forest ownership in Mississippi where limited or no harvesting takes place and where active management for timber production occurs. In the short term the total volume of timber stored per hectare is higher where no harvesting occurs. This makes sense since the forest will keep growing until it reaches its climax point and succumbs to fire, pest or disease.

Average standing volume per unit area in the private sector, where active management occurs, is the lowest as timber is periodically removed for use in solid wood products. Remember that the Oliver et al. analysis (which does not include re-growth), showed that despite a short-term reduction in forest carbon, the total displacement of high-carbon materials with wood for structural timber and energy leads to a far higher emissions saving. It is better to have a lower stock of carbon in a working forest and to be continually sequestering new carbon for storage in solid wood products.

Average standing volume per acre by ownership class, Mississippi[2]

Comparing the average annual growth rates across all forest types in Mississippi, annual growth in the private sector is almost double that in the unharvested public forest. This differential is increased even further if only commercial species like pine are considered and a comparison is made between planted, well managed forests and those that are left to naturally regenerate.

Average growth rates per acre by ownership class, Mississippi[3]

The managed forest area is continually growing and storing more carbon at a materially higher rate than less actively managed forest. As harvesting removes some forest carbon, these products displace high carbon materials in construction and energy and new young forests are replacing the old ones.

We know that forests are not being ‘lost’ and that the overall storage of carbon is increasing. For example, the Drax catchment area analysis for the Amite biomass wood pellet plant showed an increase in forest area of 5,200 ha and an increase in volume of 11 million m3 – just in the area around the pellet mill. But what happens to protected forest area, the forest reserve with limited or no harvesting?

Over the last 20 years the average annual loss of forest to wildfire in the US has been 2.78 million ha per year (the same as the UK’s total area of productive forest). According to the USFS FIA database the average standing volume of forests in the US is 145 m3 per ha (although in the National Park land this is 365 m3 per ha). Therefore, wildfires are responsible for the average annual combustion of 403 million m3 of wood p.a. (equal to the total annual wood harvest of the US) or 2.5 billion m3 if entirely in National Parks.

One cubic metre equates to a similar quantity of CO2 released into the atmosphere each year, therefore wildfires are responsible for between 407 million and 2.5 billion tonnes of CO2 emissions in the US each year[4].

Wildfires in the US

Starrs et al. (2018)[5] demonstrated that the risk of wildfire was significantly higher in federally owned reserved forest (where harvesting and management were restricted), compared to privately owned forests with active management.

In California, the risk of wildfire in federal forest (2000-15) was almost double the risk in private forests where both had State firefighting resources. The risk of fires in federal lands had increased by 93% since 1950-66, compared to only 33% in non-federal forests, due to the change in forest management practice in the 1970s.

Forest fire in California

Closing the gate means that the carbon stock is maintained and grows in the short term, but there is no opportunity for carbon to be stored in solid wood products, no high-carbon materials are displaced (concrete, steel and fossil fuels) and the rate of sequestration declines as the forest ages. Eventually the forest will reach its natural climax and die, releasing all of that carbon back into the atmosphere. The managed forest, by contrast, will have a lower standing volume at a certain point in time, but will be in a continual cycle of sequestration, storage and regrowth – with a much lower risk of fire and disease. If managed correctly, the rate of growth and standing volume will also increase over time.

How should we manage the forest

Forests are extremely variable, there are a vast variety of tree species, soil, geological features, water regimes, temperature, climate and many other factors that combine to make unique ecosystems and forest landscapes. Some of these are rare and valuable for the exceptional assemblages they contain, some are commonplace and widespread. Some are natural, some man-made or influenced by human activity.

Forests have many important roles to play and careful management is required. In some cases that management may be protection, preservation and monitoring. In other cases, it may be active harvesting and planting to optimise growth and carbon storage.

Cypress forests in the Atchafalaya Basin in Louisiana are an example of a forest landscape where the suitable management practice is protection, preservation and monitoring

For each forest type and area, we need to recognise the highest or best purpose(s) for that land in the objectives set and carefully plan the management to optimise and sustain that value. The primary value could be in species and habitat diversity or rarity; provision of recreation and aesthetic value; production of timber, forest products and revenue generation; carbon sequestration and storage; water management and other ecosystem benefits.

Most likely it will be a combination of several of these benefits. Therefore, best management practice usually involves optimising each piece of forest land to provide the most effective combination of values. Forests can deliver many benefits if we are sensible about how we manage them.

In a recent study Favero et al. (2020)[6] concluded that: Increased bioenergy demand increases forest carbon stocks thanks to afforestation activities and more intensive management relative to a no-bioenergy case. Some natural forests, however, are converted to more intensive management, with potential biodiversity losses…the expanded use of wood for bioenergy will result in net carbon benefits, but an efficient policy also needs to regulate forest carbon sequestration.

[1] CHADWICK DEARING OLIVER, NEDAL T. NASSAR, BRUCE R. LIPPKE, and JAMES B. McCARTER, 2014. Carbon, Fossil Fuel, and Biodiversity Mitigation with Wood and Forests.
[2] US Forest Service, FIA Database, 2020.
[3] US Forest Service, FIA Database, 2020.
[4] Assumes an average basic density of 570kg/m3 and 50:25:25 ratio of cellulose, lignin and hemicellulose.
[5] Carlin Frances Starrs, Van Butsic, Connor Stephens and William Stewart, 2018. The impact of land ownership, firefighting, and reserve status on fire probability in California.
[6] Alice Favero, Adam Daigneault, Brent Sohngen, 2020. Forests: Carbon sequestration, biomass energy, or both?

Trusting in trees – How four countries transformed their forests

14 November 2018

Sustainable bioenergy
Minimalist tree top with light blue sky background

From arctic-circle, snow-laden pines to damp equatorial rainforests, to dry Australian scrublands, the planet is home to an incredibly diverse range of forested environments.

And while each region is very different, almost all have been impacted by humans. The effects of this have not always been positive, and despite decades spent raising awareness of the importance of forests for the health of the world, some regions’ forests remain in decline. Africa and Asia in particular have seen a decline in forest cover (although each year sees less lost) over the past few decades.

But there are areas where the impact of humans is in fact having a positive effect. This is largely thanks to the introduction of modern sustainable forestry practices, which have incentivised growth and helped bringing a variety of environmental and economic benefits to different regions around the world.

A recent report by Pöyry Management Consulting for Drax has looked in depth at these benefits and in particular, four regions where different approaches to sustainable forestry have brought a positive impact to people, industry and the environment alike.

More than a testament to the beneficial effects sustainable forest management can have, it shows that while the tactics, methods and environments may differ, their positive effects are universal.

US South: Turning around old practices

Weyerhaeuser Nursery, Camden, Alabama

The forests of the US South, from Virginia and Kentucky to Texas and Florida, have a long history of misuse. Both indigenous people and later European settlers used disruptive techniques such as large scale burning and removed valuable, mature hardwood on a mass scale, often leaving areas to naturally regenerate.

That largely changed in the mid-20th century, however, when forestry became more-intensive and the need for sustaining a supply of quality timber grew more apparent. The introduction of processes such as thinning and managed regeneration helped usher in a more responsible approach that has led to growth in both the forestry industry and forest coverage.

Between 2010 and 2015 there was 50% more growth in the volume of forests than was removed from harvesting. More than just growing forest area, this means an increase in the amount of carbon being absorbed and stored from the atmosphere.

Charts: US South historical increment to removal and US South above ground carbon 1957-1997.

In the US South, around 86% of forest land is privately owned by either corporations or individuals, but the economics of sustainable forestry practices has encouraged the overall growth in forests, even with limited regulations on land use in the area.

In addition to the native birds and mammals that depend on sustainably managed forests in the region, more than 200,000 people were employed by the industry in 2016, making it a vital part of local rural economies.

Finland: A century-long history of sustainable practices

Asikkala, Finland by Taneli Lahtinen on Unsplash

Wood and wood products play an important role in Finnish culture, from its famous saunas to the world’s largest wooden church – multinational phone brand Nokia even started life in in 1865 as a wood pulp mill.

A high demand for wood as a commercial product meant that a few centuries ago Finland’s forests where in a state of heavy degradation. But starting as far back as 100 years ago sustainable practices such as planned harvesting and regeneration legislation were introduced. The results are significant: there is now more wood in Finnish forests today than at the turn of the century.

The majority (61%) of Finland’s forests are privately owned, with the state owning 25%, companies only owning 8%, and 5% held by other owners. Many large companies, however, offer services such as forestry work, wood sales, drainage and tax services to private owners. This collaboration between sectors allows for best practices to be easily shared and quickly become widespread.

As a result, forest stocks have increased from 1,500 million m3 in 1970 to 2,500 million m3 in 2015, even while overall forest area has remained largely the same. It highlights the effectiveness of legislation, guidelines and certification in regenerating forests.

Chart: Forest growing stock in Finland. 

UK: Incentivising growth and diversity

The UK was once thought to be 30% covered by forestland, but by the turn of the last century forests made up less than 5%. Today, however, this has grown to as much as 13%, owing largely to regulation and incentives.

Chart: Forest area in UK by country and type over previous 10 years.  

As far back as the 1700s the UK had become dependent on wood imports from New England in the US and the Baltics in Europe. Following the First World War the Forestry Commission was established, primarily to try prevent timber shortages during times of war, but it went on to drive a boom in new plantations across the country and introduce grant schemes for private plantations.

Chart: Top 10 Net Importers of Wood Products. In 2017 the UK was the world’s second largest net importer of wood products.

A problem with this afforestation, however, was that it mostly consisted of monocultures of exotic species that were well suited to the climate, rather than regenerating native species. The modern UK Forestry Standard is countering this practice by putting in place requirements for afforestation and replanting that protect biodiversity, landscape and climate change, as well as soil and water.

Forest in Argyll and Bute

Some 73% of the UK’s forests are privately owned, which includes historic estates and charitable trusts, as well as investment funds. Despite the increasing forest area in the UK over the past century, imports of both wood and wood products still make up almost 80% of the UK’s wood needs. The upside for the region is increased recreational and preserved historic forests.

Uruguay: Sustainably managing rapid expansion

Uruguay’s forestry industry is much younger than the likes of the US South or Finland, but offers an example of a how to rapidly expand the sector while preserving its ‘old growth’, or primary, forests.

Eucalyptus trees in Uruguayan working forest

In 1975 the country introduced incentives such as tax waivers on forest operations and later subsidies for new plantations, as well as tax duties for timber exports. The result was a surge in eucalyptus plantations, which grew from 25,000 hectares in 1987 to more than 1 million hectares in 2015, largely driven by interest from international companies and investors. These plantations are currently managed sustainably, with growth still exceeding removals.

Eucalyptus is not a native species to Uruguay, but by allowing international investors to plant on land deemed of no agricultural or environmental value, the country has seen enormous afforestation while 800,000 hectares of native forests remain.

The economic impact is similarly impressive. Today forestry directly employees 15,000 people in Uruguay – 55% in forestry and logging and 45% in wood processing. The skills required to work in newly constructed mills has led to several courses in forestry and wood science at Uruguayan Universities.

Chart: Total forest area development in Uruguay

These four countries take different approaches to forestry but what they have in common is forest growth exceeding that removed through harvesting. It points to sustainable forest management as a means of growing forests and, in turn, carbon extracted and stored.

Read the full report by Dr. Hannes Lechner and Dr. Jack Lonsdale: Assessment of the benefits of sustainable forest management [PDF]

The everyday and future ways you use forest products

24 August 2018

Sustainable bioenergy

Think of the products that come from forests and you might think of the centuries of shipbuilding, construction and cooking made possible by civilisations utilising this plentiful natural resource.

What you might not think of is the complex construction of chemicals and matter that make up the trees of a forest – nor of the countless ways these can be broken down and used. Yet this is the reality of forests. From essential oils to sturdy packaging to powerful adhesives, trees are used to create a range of products that make daily life possible.

And as awareness of the need to reduce plastic consumption grows, research into forest products and how they can replace the less-environmentally friendly objects is growing.

Here we look at five of the most common products used today, and maybe in the future, that owe something to forests.

Adhesives from tall oil

Anyone who has encountered tree sap can attest: trees are made up of some pretty sticky stuff. And it’s because of this that they have long been a source for adhesives production – from glue to cement.

The substance that makes this possible is known as tall oil. Named after the Swedish word Tallolja, meaning pine oil, it is a by-product of pulping coniferous trees.

Tall oil has been produced commercially since the 1930s when the invention of the recovery boiler made it possible to extract it from the Kraft pulping process. However, the resins and waxes tall oil is made up of have a longer history. These are also known as ‘Naval Products’ due to their historic use in ship building and can be tapped directly from living trees.

Today, tall oil is also used in asphalt roofing, as well as medical and cosmetic applications. One of tall oil’s most exciting uses is as BioVerno – a renewable alternative to diesel made in the world’s first commercial-scale biorefinery in Finland.

Disinfectants and detergents from turpentine

Tapping trees has historically been a means of extracting multiple useful substances and one of the most versatile of these is turpentine. This yellowish liquid is produced from distilled tree resin and has a long history of uses.

Turpentine has been used since Roman times as torch or lamp fuel, but its antiseptic properties also means it was often used as medicine. While doctors today would advise against drinking turpentine (as was prescribed in the past), it is still used today in disinfectants, detergents and cleaning products, giving off a fresh, pine-like odour.

Fuels to replace fossils

Biomass pellets from working forests are just one of the ways trees are providing renewable energy. One other form is cellulosic ethanol, a new, second generation of liquid biofuel. Rather than competing with food supply (often a concern in the creation of biodiesels), cellulosic ethanol is made from non-food based materials such as forest and agricultural residues left behind after harvest – wheat straw, – and timber processing wastes including sawdust. It is now being produced at a commercial scale in Europe, the US and Brazil.

Woody biomass can also be converted into a petroleum substitute known as pyrolysis oil or bio-oil. Biomass is transformed into this dark brown liquid by heating it to 500oC in an oxygen-deprived environment and then allowing it to cool. Bio-oil has a much higher energy density than biomass in chip or pellet form and after upgrading can be used as jet fuel or as a petroleum alternative in chemical manufacturing.

Vanilla ice cream and carbon fibre from lignin

Lignin is what gives trees their tough, woody quality, and after cellulose is the world’s second most abundant natural polymer. Polymers are very long molecules made up of many smaller molecules joined end-to-end most often associated with plastic, (which is a synthetic polymer).

Lignin is generally a waste product from the paper pulping process and is often burnt as fuel. However, it can also serve as a vanilla flavouring – a property that may make lignin an important resource in the face of an impending vanilla pod shortage.

Future-looking research, however, aims to unlock much more from the 50 million tonnes of lignin produced every year globally. One of the most promising of these is as an alternative source of a family of organic compound known as phenylpropanoids. These are normally extracted from petroleum and are hugely useful in producing plastics and carbon fibre, as well as drugs and paint. 

Nanocellulose and the future of forest products

Cellulose is already one of the most important products to come from forests thanks to its role in paper production. However, this abundant substance – which is also the primary material in the cell walls of all green plants – holds even more potential.

By shrinking cellulose down to a nano level it can be configured to be very strong while remaining very light. This opens it up as a product with many possibilities, including using it as a source of bioplastics. Some bioplastics – polylactic acid, PHA, PBS and starch blends – are biodegradable alternatives to fossil fuel-based plastics and could potentially help solve some of the world’s most-pressing waste issues.

Not all bio-based plastics are biodegradable, however. The property of biodegradation doesn’t depend on the resource basis of a material – it is linked to its chemical structure. In other words, 100% bio-based plastics may be non-biodegradable, and 100% fossil-based plastics can biodegrade.

Bio-based plastics that are not biodegradable include polyethylene terephthalate, polyurethanes, polyamide, polyethylene. Polyethylenefuranoate or PEF is recyclable, can be manufactured without fossil fuels and while not biodegradable, has the potential to become a more sustainable alternative to the oil-based plastic used to make water bottles.

Cellulose’s combination of strength and light weight has also attracted interest from the auto industry in the ability to help cars become much lighter and therefore more fuel efficient. Its flexible, strong, transparent nature can also make Nanocellulose – an important material in helping bring bendable screens, batteries, cosmetics, paper, pharmaceuticals, optical sensors and devices to market.

The idea of using trees as a source of goods and products in everyday life might sound archaic, but, in reality, we’ve only just tapped the surface of what the chemicals and materials they’re made of can do. Markus Mannström from Finnish renewables company Stora Enso said recently that: “We believe that everything made from fossil-based materials today, can be made from a tree tomorrow.” As research advances, trees and forests will only play a bigger role in a more sustainable future.

Better forest management 

5 June 2018

Sustainable bioenergy

One of the most interesting outcomes of the recent analysis from the UK’s Forest Research (FR) agency on the Carbon Impact of Biomass (CIB) is the call for regulation to ensure better forest management and appropriate utilisation of materials.

The research was commissioned by the European Climate Foundation (ECF) to follow up FR’s mighty tome from 2015 of the same name.

This new piece of work essentially aims to clarify the findings of the initial research with supplementary analysis to address 3 key areas:

  1. A comparison of scenarios that may give relatively higher or lower GHG reductions — in simple terms, providing examples of both good and bad biomass.
  2. Based on the above, the report “provides a statement of the risks associated with EU bioenergy policy, both with and without specific measures to ensure sustainable supply.”
  3. It then goes on to “provide a practical set of sustainability criteria to ensure that those bio feedstocks used to meet EU bioenergy goals deliver GHG reductions”.

Not surprisingly, the report finds that unconstrained and unregulated use of biomass could lead to poor GHG emission results, even net emissions rather than removals. This, again, is a no-brainer. No reasonably minded person, even the most ardent bio-energy advocate, would suggest that biomass use should be unconstrained and unregulated.

There are plenty of obvious scenarios where biomass use would be bad, but that doesn’t mean that ANY use of biomass is bad. Thankfully this analysis takes a balanced view and identifies a number of scenarios where the use of biomass delivers substantial GHG emission reductions.

The report identifies the use of forest and industrial residues and small/early thinnings as delivering a significant decrease in GHG emissions, this is characterised as “good biomass” — around 75% of Drax’s 2017 feedstock falls into these feedstock categories (including some waste materials).

The remainder of Drax’s 2017 feedstock was made up of low grade roundwood produced as a bi-product of harvesting for saw-timber production. This feedstock was not specifically modelled in the analysis, but the report concludes that biomass users should: Strongly favour the supply of forest bioenergy as a by-product of wood harvesting for the supply of long-lived material wood products. The low grade roundwood used by Drax falls into this category.

Among the more obvious suggested requirements are that biomass should not cause deforestation and that biomass associated with ‘appropriate’ afforestation should be favoured. Agreed.

Another interesting recommendation is that biomass should be associated with supply regions where the forest growing stock is being preserved or increased, improving growth rates and productivity. Drax absolutely supports this view and we have talked for some time about the importance of healthy market demand to generate investment in forest management, encourage thinning and tree improvement.

Timber markets in the US South have lead to a doubling of the forest inventory over the last 70 years. These markets also provide jobs and help communities and ensure that forests stay as forest rather than being converted to other land uses.

The importance of thinning, as a silvicultural tool to improve the quality of the final crop and increase saw-timber production, is recognised by Forest Research. This is an import step in accepting that some biomass in the form of small whole trees can be very beneficial for the forest and carbon stock but also in displacing fossil fuel emissions.

The forest resource of the US South is massive, it stretches for more than a thousand miles from the coast of the Carolinas to the edge of West Texas, a forest area of 83 million ha (that’s more than 3 times the size of the UK). Given that a wood processing mill typically has a catchment area of around a 40–50-mile radius, imagine the number of markets required for low grade material to service that entire forest resource!

So, what happens when there isn’t a market near your forest, or the markets close? Over the last 20 years more than 30 million tonnes of annual demand for low grade timber — thinnings and pulpwood — has been lost from the market in the US South as the paper and board mills struggled after the recession. What happens to the forest owner? They stop harvesting, stop thinning, stop managing their forest. And that reduces the rate of growth, reduces carbon sequestration and reduces the quantity of saw-timber that can be produced in the future. Recognising that biomass has provided essential markets for forest owners of the US South, and directly contributed to better forest management is a really important step.

The CIB report talks about different types of biomass feedstock like stumps, which Drax does not use. Conversely the report also identifies good sources of biomass which should be used such as post-consumer waste, which Drax agrees would be better utilised for energy where possible, rather than land fill. It also shows that industrial processing residues that would otherwise be wasted and forest residues that would be burnt on site or left to rot would deliver carbon savings when used by facilities like Drax.

All of these criteria are similar to those outlined in the 7 principles of sustainable biomass that Drax has suggested should be followed.

Among the other recommendations which echo Drax’s thinking are that biomass should not use saw-timber or displace material wood markets, the scale should be appropriate to the long term sustainable yield potential of the forest — it should be noted that harvesting levels in the US South are currently only at around 57% of the total annual growth.

Counterfactual modelling, like that used in this report, cannot take account of all real-world variables and must be based on generic assumptions so should not be used in isolation, but this report makes a very useful contribution to a complex debate.

It is possible to broadly define good and bad biomass and to look at fibre baskets like the US south and see a substantial surplus of sustainable wood fibre being harvested a rate far below the sustainable yield potential.

Drax is currently working with the authors of this report, and others in the academic world, to develop the thinking on forest carbon issues and to ensure that all biomass use is sustainable and achieves genuine GHG emission reductions.

Discover the steps we take to ensure our wood pellet supply chain is better for our forests, our planet and our future — visit ForestScope

Collaborating for biodiversity protection and enhancement

21 March 2018

Sustainable bioenergy

Drax Biomass conducts regional risk assessments with extensive reviews of existing public and private datasets to identify high conservation value forests. This regional information is then augmented by county-level Natural Heritage data.

In 2017, Drax Biomass contracted with Nature Serve to package this regional- and county-level data into a format that would facilitate a rapid risk assessment for all in-woods fibre. This operational risk assessment procedure, combined with formal conservation commitments such as the Atchafalaya Basin Keeper agreement, reflect a comprehensive strategy to protect biodiversity.

Drax Biomass is looking forward to actively contributing to regional conservation enhancement efforts in 2018 and beyond.

A partnership formed with the American Forest Foundation (AFF) in 2017 is paving the way. The AFF is a publicly supported not-for-profit organization established to conduct charitable, educational, research and scientific programmes aimed at the responsible use and conservation of renewable resources. Our partnership with the AFF is aimed at improving habitat for at-risk southern wildlife species through active forest management. With open-canopy pine habitat identified as a conservation need, the market that Drax Biomass provides for small-diameter forest thinning material can directly benefit the regional biodiversity.

In addition to efforts around our own facilities, Drax Biomass employees have been contributing to a collaborative effort run by the Sustainable Biomass Program (SBP) to provide better information on how to assess whether or not there are forests with high conservation values in a catchment, and what to do about them. SBP expects to publish the guidance from this workgroup in early 2018.

The Sustainable Biomass Program

Sustainable bioenergy

In 2013, Drax co-founded the SBP together with six other energy companies.

SBP builds upon existing forest certification programmes, such as the Sustainable Forest Initiative (SFI), Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forest Certification (PEFC). These evidence sustainable forest management practices but do not yet encompass regulatory requirements for reporting greenhouse gas (GHG) emissions. This is a critical gap for biomass generators, who are obligated to report GHG emissions to European regulators.

There is also limited uptake of forest-level certification schemes in some key forest source areas. SBP is working to address these challenges.

SBP certification provides assurance that woody biomass is supplied from legal and sustainable sources and that all regulatory requirements for the users of biomass for energy production are met. The tool is a unique certification scheme designed for woody biomass, mostly in the form of wood pellets and wood chips, used in industrial, large-scale energy production.

SBP certification is achieved via a rigorous assessment of wood pellet and wood chip producers and biomass traders, carried out by independent, third party certification bodies and scrutinised by an independent technical committee.