Spruce trees are abundant and widely distributed in the US. Some species of spruce are among the fastest-growing and largest trees in North America. The high availability and large size are telltale signs of the sustainability of spruce wood. However, spruce-fir forests play a significant role for wild animals, insects, and birds. So we had to ask: How sustainable is it to buy products made out of spruce wood?

Spruce wood is sustainable thanks to its carbon sequestration. The fast growth and the wide spreading of spruce species mean it’s possible to harvest spruce timber without harming the forest. Also, emissions from transporting are considerably lower than for imported wood.

In this article, we’ll walk you through the life-cycle of spruce wood used for furniture, musical instruments and in construction projects. Then, we evaluate its sustainability, potentials, and shortfalls. And in the end, we’ll show you tips for buying sustainable spruce wood. 

Here’s How Sustainable Spruce Wood Is

Spruce wood is a sustainable material because of the trees’ carbon sequestration and the carbon offset value at the end of any products made with spruce wood. 

“Sustainable: The ability to be maintained at a certain rate or level | Avoidance of the depletion of natural resources in order to maintain an ecological balance”

Oxford Dictionary

To better understand the sustainability of spruce wood, we assess the life-cycle of projects like flooring or furniture. This life-cycle assessment (LCA) is a method to evaluate the environmental impacts of each stage in a product’s life-cycle, from the making to the recycling. Over the years, companies have strategically used LCA to research and create more sustainable products. 

In this article, we’ll use the cradle-to-grave perspective of the LCA, examining the five stages of the life cycle of spruce wood. Where it is relevant, we also use data from cradle-to-gate assessments. 

Overall, we can say that spruce wood is sustainable. However, the actual environmental impact of a particular product, like a violin or a window frame, depends on many factors, especially the distance and mode of transportation. Let’s dive deeper into each stage and find out how it can be more sustainable. 

How Sustainable Is the Growing Spruce Wood

Growing spruce trees for timber is sustainable thanks to the carbon sequestration potential and high availability of these species. 

What Type of Wood Is Spruce Wood and What Does This Mean for Sustainability

Spruce wood comes from the softwood tree species in the Picea genus of the Pinaceae family, which also includes pine and Douglas fir. 

Some US native spruce species in this coniferous evergreen tree genus are: 

• Sitka Spruce (Picea sitchensis)
• Engelmann Spruce (Picea engelmannii)
• White Spruce (Picea glauca)
• Red Spruce (Picea rubens)
• Black Spruce (Picea Mariana)
• Colorado spruce (Picea pungens)

Sitka spruce and Engelmann spruce are two of the most important timber trees in the genus. 

Among the 35 spruce species, growth speed varies from slow to moderate to very fast.

Sitka spruce, Picea sitchensis, is one of the fastest-growing tree species in North America. In ideal conditions, young trees may increase by 5 feet in height every year. In comparison, Douglas fir and most pine species have annual growth between 1 and 2 feet, while the fast-growing redwood trees’ yearly growth is about 3 feet. 

On the other hand, Engelmann Spruce, Picea engelmannii (another important timber species), grows very slowly. Five-year-old seedlings average 1 to 3 inches in height under natural conditions. Growth speed increases as trees get older, but the rate is still fairly slow. After 20 years in full sun, an Engelmann Spruce tree may only reach 5 feet in height. It takes 40 years for a tree to get such size if growing under moderate shade. 

How Sustainably Does Spruce Wood Grow

Spruce trees’ sustainability lies in the potential for carbon sequestration, their availability geologically, and the amount of wood. 

• Carbon sequestration: As spruce trees grow, they absorb CO₂ from the atmosphere while releasing oxygen. They act as a carbon sink during their long lifespan. 

Generally, spruce species are long-lived. Engelmann spruce, for example, matures at around 300 years. It is not uncommon to find trees of this species aged 500 to 600 years old. Sitka spruce can live up to 800 years. 

As a carbon sink, spruce trees pull a lot of greenhouse gasses out of the atmosphere, helping to mitigate the climate crisis. And they can store a lot as they grow big and tall. Red spruce, for example, can reach 110 feet in height and 4.5 feet in diameter. Engelmann spruce and Sitka spruce trees grow even higher.

• High availability: Spruce wood is highly available thanks to the wide distribution and the large sizes of various timber species in this genus.

Sitka spruce trees are among the most prominent forest trees in stands along the northwest coast, while Engelmann spruce trees can be found throughout the western states. 

Spruce species adapt to a variety of climates and soil. Some grow in coastal lowlands and others thrive in high mountains. 

In addition to their wide distribution throughout the US, spruce trees also grow in great numbers. Engelmann spruce is one of the eight most common trees in the west of the US.

Lastly, spruce trees are very large, providing a lot of timber.

Sitka spruce is the third-largest tree species in the world (after redwood and Douglas fir). 

Though not quite the size of Sitka spruce, the Engelmann spruce trees also tend to grow very large in size. It is among the largest high-mountain tree species. 

Where Is Spruce Wood Usually Grown

Spruce is a genus of evergreen conifers native to the temperate and cold regions of the Northern Hemisphere. Seven (of about 35 spruce species) are indigenous to the US. 

Spruce trees are found throughout the US, sometimes in (near) pure stands but often with fir trees. Spruce-fir forests play an important role for wildlife, and harvesting spruce from these forests, especially done illegally or unsustainably, can result in biodiversity loss. 

One example is when loggers only cut down the biggest and tallest trees. That pattern would cause a reduction in the genetic diversity and quality of the trees within the stand, leading to gradual degradation of tree quality. 

Cutting down spruce trees also disrupts the forests’ wild animals, which depend on the forest for food and shelter. 

Spruce-Fir forests, especially ones growing on lowlands, support large trees and a diverse community of plants and animals. While spruce trees can generally live for a long time, some fir trees sharing the same forests are short-lived. Thus, they create a complex forest structure – trees of different ages and sizes, fallen logs, and dead trees. Such a forest structure can support many species. 

In Colorado, spruce-fir forests provide important habitat to red squirrels, snowshoe hares, pine martens, boreal owls, Clark’s nutcrackers, and three-toed woodpeckers.

In North Carolina, spruce-fir forests provide a critical breeding ground for many rare birds. Those forests are essential habitats for rare animal species. Some examples are the federally-endangered Carolina northern flying squirrel, spruce-fir moss spider, and salamander (Northern pygmy s and Weller’s). 

Illegal logging in the US is unfortunately not non-existent. The only way for you as a consumer to tackle problems caused by illegal logging is to source sustainable woods. We will point you in the right direction with spruce Wood at the end of this article. 

In total, logging of forestry products from plantations accounts for 26% of forest loss, which is a combination of deforestation and forest degradation. However, the loss in bio-diverse forests in tropical climates is more significant (and sometimes less properly recorded) than in temperate, well-managed logging forests. 

How Sustainable Is the Manufacturing of Spruce Wood

Turning spruce wood into furniture has a relatively low carbon footprint because wood waste can be recycled fully as by-products or biomass pellets to offset the carbon emissions during harvesting and processing. 

The first step of manufacturing spruce furniture and musical instruments involves cutting down trees and turning them into lumber in a sawmill. Electricity is needed to run sawing machines. 

The next step is to dry lumber before turning it into a household item. If a piece of lumber can be air-dried to the desired moisture content, no added energy is needed for this step. However, if a kiln is used, it requires extra energy, which could mean higher carbon emissions.

Spruce timber dries relatively fast with a low tendency of checking and warping. 

According to the US Forest Service, air-drying green 1-inch lumber of Engelmann spruce to a 20% moisture content takes 20 to 120 days. 

Compared with other US hardwoods and softwoods, spruce is one of the fastest-drying timbers. 

One softwood dries faster: sugar pine timber was reported with a shorter drying time (15 to 90 days). Silver maple is the only US hardwood with a similar drying time (30 to 120 days). 

All other hardwoods and softwoods were reported with longer air-dry times. 

The moisture content of 20% is often not low enough for making furniture, musical instruments, or being used in house building projects. Because the ideal moisture content is 6 to 7%, a kiln is often necessary to speed up the drying time. 

It can take 54 to 74 hours to dry 2-inch spruce lumber timber to a 6% moisture content in a kiln set to a conventional schedule. Using a low-high temperature kiln schedule can shorten the drying time to 40 to 50 hours. 

A high proportion of energy (power sawing machines and kilns) can come from renewable sources, including solar, wind, hydroelectric, geothermal, and biomass. According to a Cradle to Gate Life-Cycle Assessment from the US Forest Service, the energy generated from biomass to dry US softwood lumber (including spruce species) is almost double the fossil fuel energy. 

How Sustainable Is the Transportation of Spruce Wood

Transporting is a relatively carbon-intensive stage in the life cycle of spruce Wood furniture due to the emissions associated with operating the hauling vehicles that take timber to sawmills and factories, then furniture to stores. 

As spruce wood is a local timber from fast-growing softwood trees, the carbon emissions of transporting spruce products would be considerably lower than imported tropical timber, like ipe, teak, or mahogany. 

The actual emission during this stage depends on the type of vehicles used, the fuel they need, and the distance the wood travels. Calculations made by the Norwegian Forest and Landscape Institute showed that smaller wood hauling trucks emitted more CO₂ per transported cubic meters of timber: 1.25 times more than larger wood hauling trucks, 1.3 times more than sea vessels, and six times more than freight trains. Therefore, the sustainable transportation option would be rail or large trucks running on biofuel. You can check with your wood suppliers how their products are transported and opt for the best option. 

How Sustainable Is the Usage of Spruce Wood

Using spruce furniture can be sustainable thanks to the carbon capture during the products’ long life. 

The durability of timber varies among different spruce species. However, spruce is generally considered strong for its weight. The resistance-weight ratio of spruce is among the highest. 

Because species in this genus have no insect or decay resistance qualities, they don’t last long outdoors (likely less than two years). Using indoors with proper care, a spruce window frame, for example, can last 25 years. 

When spruce wood is decayed, either naturally in the forest or because of damage caused by usage at home, the carbon stored in the wood is released back to the atmosphere. Therefore, long-lasting furniture can be considered a good way of keeping carbon out of the atmosphere. If the wood is then reclaimed for making another piece of furniture, its positive carbon storage environmental impact is even higher. 

How Sustainable Is the End-of-Life of Spruce Wood

The end-of-life stage for spruce wood furniture and musical instruments is sustainable when the wood is reused or burned as bioenergy.

There are a few scenarios for wood products – outdoor furniture, musical instrument and building material – at the end of their life: 

1. They can end up in landfills and don’t decompose. In this case, it keeps its role as carbon storage.
   
2. Wood products can also be upcycled and reused, extending their role as carbon storage. New wood products often travel much further to their markets, compared with recovered wood products. The latter is typically made in urban centers and sold locally, which lowers the transportation environmental burdens.
   
3. In another end-of-life scenario, products like a tulip cabinet can be burned for biomass energy displacing coal or natural gas in generating electricity.

With smaller household items, like a doorknob or a small chair, the offset won’t be as high as there is much less waste for burning. However, if such products are made from manufacturing wood waste as by-products, their carbon footprint is minimal. 

In a cradle-to-grave assessment, the overall results show a negative carbon footprint for a spruce window frame. Based on this climate indicator, spruce wood is the most environmentally friendly material, better than other softwoods (Scots and Radiata Pine), the hardwood beech, and non-wood materials (aluminum and PVC).

How Can You Buy Spruce Wood More Sustainably

The key to sustainably buying any wood is to check on relevant environmental and original certifications. Reliable certifications for sustainable woods are: 

• Forest Stewardship Council: 

An FSC certification ensures that the spruce wood comes from responsibly managed forests that provide environmental, social, and economic benefits.

• Program for Endorsement of Forest Certification: 

PEFC’s approaches to sustainable forest management are in line with protecting the forests globally and locally and making the certificate work for everyone. Getting a PEFC certification is strict enough to ensure the sustainable management of a forest is socially just, ecologically sound, and economically viable but attainable not only by big but small forest owners. 

Why Is It Important to Buy More Sustainable Wood

Buying sustainable wood also means helping to prevent illegal or unsustainable logging, which harms the forests’ biosystems and accelerates climate change. 

Logging of forestry products from plantations accounts for 26% of forest loss. Cutting down trees for wood has a lesser impact on carbon storage than digging up the whole forest floor and turning it into farms or mines. However, if logging is not sustainably managed, it can badly damage wildlife.

When logging happens in tropical forests – the bio hotspots of our planet – the biodiversity loss can be much more damaging. Subtropical and tropical forests are packed with unique wildlife – endemic mammals, birds, and amphibians. The displacement of such wildlife during poorly managed logging would be a major contributor to global biodiversity loss. 

Sustainable management of forests also means that trees are cut down for timber only when they are mature. These trees will then be able to regrow and eventually replace the loss of canopy, absorb carbon from the atmosphere and reduce the effect of climate change. 

Final Thoughts

You can buy sustainable furniture and musical instruments made from spruce wood as long as the timber comes from sustainably managed forests. And, to make it even more sustainable, use any spruce wood item for as long as you can, upcycle the material to extend its usage, and arrange for it to be recycled fully.

Stay impactful,

Sources

• Science Direct: Life-cycle assessment (LCA)
• MIT SMR: Strategic Sustainability Uses of Life-Cycle Analysis
• European Environment Agency: cradle-to-grave
• Science Direct: Cradle-to-Gate Assessment
• Britannica: spruce
• Impactful Ninja: How Sustainable Is Pine? Here Are the Facts
• Impactful Ninja: How Sustainable Is Douglas Fir Wood? Here Are the Facts
• THE WOOD DATABASE: SITKA SPRUCE
• THE WOOD DATABASE: ENGELMANN SPRUCE
• THE WOOD DATABASE: WHITE SPRUCE
• THE WOOD DATABASE: RED SPRUCE
• THE WOOD DATABASE: BLACK SPRUCE
• AMERICAN CONIFER SOCIETY: Picea pungens/Colorado spruce
• AMERICAN CONIFER SOCIETY: Picea sitchensis/Sitkaspruce
• Impactful Ninja: How Sustainable Is Redwood? Here Are the Facts
• U.S FOREST SERVICE: Picea engelmannii Parry ex Engelm
• Forests for Oregon: Sitka Spruce
• Nature: Over half of western United States’ most abundant tree species in decline
• University of New Hampshire: Lowland Spruce-Fir Forests
• COLORADO STATE FOREST SERVICE: SPRUCE FIR
• U.S FOREST SERVICE: Spruce-Fir Forest Ecological Zone 
• Our World in Data: Deforestation and Forest Loss
• OREGON STATE UNIVERSITY: COMPARISON OF KILN SCHEDULES FOR DRYING SPRUCE 
• U.S FOREST SERVICE: Cradle to Gate Life Cycle Assessment of Softwood Lumber Production from the Northest-North Central
• Impactful Ninja: What Is the Carbon Footprint of Biomass Energy? A Life-Cycle Assessment
• Impactful Ninja: How Sustainable Is Ipe Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Teak Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Mahogany Wood? Here Are the Facts
• Science Norway: Larger logging trucks give less CO₂ emissions
• Accoya: Life Cycle Assessment of Accoya Wood and its applications
• Research Gate: Life cycle primary energy and carbon analysis of recovering softwood 
• Forest Stewardship Council
• Program for Endorsement of Forest Certification
• Our World in Data: Epidemic Mammal Species