By
Quynh Nguyen

The durable and exotic cumaru wood comes from some of the tallest tree species in the Amazon Rainforest. When cumaru trees are cut down illegally and/or excessively, much damage is done to one of the richest ecosystems on earth. So we had to ask: How sustainable is it to buy products made out of cumaru wood? 

Cumaru wood is generally a sustainable material thanks to carbon sequestration and storage. However, illegal logging and clear-cutting in cumaru trees’ rainforest homes have a high ecological cost. Also, the often long distances that cumaru timber travels to markets make it much less sustainable. 

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

Here’s How Sustainable Cumaru Wood Is

Cumaru timber is a sustainable material because of the cumaru trees’ carbon sequestration potential and the carbon offset value at the end of any products made with cumaru wood. It is important to note that the rampant illegal logging and unsustainable practices in rainforests where cumaru trees grow natively have a very high environmental cost. However, when sourced from sustainably managed forests, wood is better for the environment than plastic.

“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 cumaru 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 cumaru wood. Where it is relevant, we also use data from cradle-to-gate assessments. 

The life-cycle stages of cumaru wood	Each stage’s sustainability
Growing of cumaru wood	Growing cumaru in its native tropical forests is sustainable because of carbon sequestration and carbon storage in the tree and its rooting system. Illegal logging and clear-cutting of cumaru trees cause much ecological damage, and you absolutely need to avoid any cumaru timber harvested in such ways.
Manufacturing of cumaru wood	Turning cumaru 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.
Transporting of cumaru wood	Transporting is a relatively carbon-intensive stage in the life cycle of cumaru wood furniture due to the emissions associated with operating the hauling vehicles that take timber to sawmills and factories, then furniture to stores. As cumaru timber in the US would have come from Central or South America, cumaru furniture or decking would have a higher carbon footprint than furniture made with regionally available wood.
Usage of cumaru wood	Using cumaru wood furniture can be sustainable thanks to the carbon capture during the products’ long life.
End-of-life of cumaru wood	The end-of-life stage for cumaru wood furniture is sustainable when the wood is reused or burned as bioenergy.

We’ll say that it is possible to find sustainable products made from cumaru wood. However, the actual environmental impact of a particular product, like a fence or garden decking, depends on many factors, especially the forest management practices and 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 of Cumaru Wood

Growing cumaru in its native tropical forests is sustainable because of carbon sequestration and carbon storage in the tree and its rooting system. Illegal logging and clear-cutting of cumaru trees cause much ecological damage, and you absolutely need to avoid any cumaru timber harvested in such ways. 

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

Cumaru wood comes from slow-growing hardwood trees of the Dipteryx species, including Dipteryx odorata, Dipteryx micrantha, and Dipteryx alata. Some other local names for cumaru trees are Tonka, Brazilian Teak, and Shihuahuaco. 

Dipteryx tree species(the ones cumaru wood belongs to) are slow growers from the tropics. The shihuahuaco or Dipteryx micrantha, for example, can take up to a thousand years to reach the full height of 200 feet.  

How Sustainably Does Cumaru Wood Grow

Living cumaru trees can mitigate global warming impact through carbon sequestration. However, because these high-value timber tree species grow in low density, there is a high tendency for illegal logging and/or clear-cutting. Such unsustainable harvesting practices have a very high ecological cost. When they occur, cumaru timber is much less sustainable than timber from sustainable managed temperate forests, such as FSC-certified Douglas fir or maple.  

• Low density: Similar to ipe, cumaru trees grow sparsely in their native rainforest. They scattered throughout the forest alongside other species. For example, there are, on average, over 100 timber species for every 2.5 acres of the Peruvian rainforest. 

In the case of clear-cutting, a large area of forest is cut down to reach a few cumaru (and some other timber) trees. Firstly that means felling many trees of little commercial value (but possibly of much ecological value). Secondly, such practice creates islands of forests with isolated ecosystems which are much less biodiverse and disaster-proof. 

It is possible to increase the density of cumaru trees by growing them in tree plantations. However, there is a big difference in biodiversity in tree plantations and native forests, especially the rainforests. The rich and biodiverse ecosystems of the Amazon can’t (yet) be recreated somewhere else. 

When cumaru trees are grown in sustainably managed forests, the carbon sequestration and carbon storage in tree trunks and roots (as well as in timber and wood products) contribute to its being more sustainable than materials like wood plastic composite. These tree species are also good candidates for agroforestry systems. 

• Carbon sequestration: As cumaru trees grow, they absorb CO₂ from the atmosphere while releasing oxygen. They act as a carbon sink during their long lifespan up to 1000 years, with some of the oldest species living over 1200 years. This means that they are taking greenhouse gases out of the atmosphere, helping to mitigate the climate crisis. 

And they can store a lot as they reach the Amazon Rainforest’s topmost layers (i.e., the Canopy Layer and the Emergent Layer). The Dipteryx odorata species, for example, grow to a height of 130 to 160 feet with a trunk diameter of 3 to 5 feet. These cumaru trees are taller than some other South American timber tree species like ipe or mahogany. 

• Agroforestry land usage: Cumaru trees are an excellent component of Amazonian agroforestry systems (i.e., the intentional combination of agriculture and forestry to create productive and sustainable land-use practices). Such sustainable food production systems are much better for the Amazon forests than the slash-and-burn farming approach. 

For example, some Amazonian communities incorporate cumaru trees into systems that provide cassava, fruits, nuts, and timber products over a cycle of 30 years. That is a much longer period without burning the forest compared with the slash-and-burn method. In agroforestry systems, cumaru trees can play different roles. They regenerate deforested, burned land, provide shade in plantations, and benefit farmers with two valuable products: timber and seeds. 

Where Is Cumaru Wood Usually Grown

Cumaru tree species grow in rainforests in parts of Central America and northern South America. Brazil, Peru, Colombia, Venezuela are some of the few countries whose rainforests are home to cumaru trees. 

Harvesting cumaru timber from natural forests, especially when done illegally or unsustainably, can result in biodiversity loss regarding the tree species and wild animals that feed and shelter in the woods. 

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 cumaru trees also disrupts the forests’ wild animals, which depend on the forest for food and shelter. The fruits of shihuahuaco trees – the Dipteryx micrantha species – play a significant part in the diet of bats, spider monkeys, agoutis, possums, squirrels, and spiny rats. Macaws nest in the natural hollows in the trunk. Harpy eagles, the largest raptor in the rainforest, also make home in this tree species. 

The Amazon rainforest – home of cumaru tree species – is one of the most biodiversity places on earth. It hosts over three million species, including over 2,500 tree species. That is one-third of all tropical trees that exist on earth. Thus, cutting down trees and displacing animals in the Amazon Rainforest has a very high ecological cost.

Illegal and overlogging in the Amazon Rainforest have been an alarming problem for a long time. As cumaru timber gains popularity as a cheaper and more sustainable alternative to ipe for decking, cumaru trees have been increasingly targeted for illegal felling. In the Peruvian Amazon, for example, excessive logging is pushing cumaru to the brink of extinction. Cumaru trees are now in the company of endangered species like mahogany and cedar. The volume of cumaru extracted in the Peruvian Amazon in 2013 was 22 times the volume in 2000. 

Cumaru trees are classified as the Amazon’s keystone species – species vital to community stability and diversity because they provide food resources to vertebrate consumers during the season of scarcity. Unregulated logging of cumaru tree species, thus, reduces the biodiversity of the forests and converts part of the forests into savannas. 

The only way for consumers to tackle problems caused by illegal logging is to source sustainable woods. We will point you in the right direction with cumaru 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 Cumaru Wood

Turning cumaru 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 cumaru wood furniture involves cutting down trees and turning them into lumber in a sawmill. The carbon emissions here come from electricity usage. In a cradle-to-gate assessment of cumaru deckings produced in northern Brazil, harvesting and sawmilling 1m³ of cumaru decking released on average 32.6kg CO₂ eq. That is slightly higher than the average emission of harvesting and sawmilling 1m³ of ipe (29.7kg CO₂ eq) – another South American hardwood popular for decking assessed in the same study. 

The next step is to dry lumber before turning it into furniture. 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. 

Cumaru timber that is air-dried slowly has a tendency to form cracks and checks. While some other tropical wood like ipe timber can be air-dried to the optimum moisture content, cumaru often requires kiln drying for commercial use. 

If fossil fuel is used to operate a kiln, it adds to the total carbon emissions. However, burning wood waste (biomass) generates energy that could replace fossil fuels. Luckily, at least 90% of all thermal energy used for kiln drying in the US hardwood sector comes from biomass (instead of fossil fuels). 

Kiln-drying can also be fuelled with other types of non-fossil energy, such as solar power or hydropower, resulting in a smaller carbon footprint. For example, in northern Brazil, 85-90% of electricity obtained from the grid (to run kilns) is generated by hydropower. Manufacturers can avoid fossil fuel by combining hydro-powered electricity from the grid and the power they generate from their own biomass. 

The low carbon footprint of timber drying contributes to a more favorable carbon footprint of cumaru timber manufactured in northern Brazil than kiln-dried Khaya timber – the so-called African mahogany. The carbon footprint of 1m3 of cumaru decking in Northern Brazil (including harvesting, sawmilling, lumber transporting, and manufacturing) is 77.3kg CO2 eq, three times less than kiln-dried Khaya lumber produced in Ghana (253.1 kg CO2 eq). 

Many kinds of tropical woods, including cumaru, do not require surface treatment thanks to a high content of natural oils, protecting the wood from fungi and pests. And no surface treatment means that less energy is needed for producing and applying the substance. And also that the furniture can be recycled fully at the end of its life, making it more sustainable. 

How Sustainable Is the Transportation of Cumaru Wood

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

As cumaru timber in the US would have come from Central or South America, cumaru furniture or decking would have a higher carbon footprint than furniture made with regionally available wood, like pine or white oak. 

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 more sustainable option. 

How Sustainable Is the Usage of Cumaru Wood

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

Cumaru is exceptionally dense, hard, and durable. Cumaru is, in fact, one of the hardest woods with a Janka rating of 3540lbf. The timber has excellent weathering properties, resisting rotting and decay caused by moisture. Because of its resistance to moisture, cumaru is one of the tropical hardwoods preferred for outdoor decking. It is considered as of similar quality as ipe but more readily available, thus more environmentally friendly. 

In terms of lifespan, outdoor products made of cumaru wood, such as a fence or garden decking, can easily last two decades or even longer. 

When cumaru 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 Cumaru Wood

The end-of-life stage for cumaru wood furniture is sustainable when the wood is reused or burned as bioenergy. 

There are a few scenarios for wood products – furniture or flooring – 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 and reducing the fossil CO₂ emitted as much as four times when comparing, for example, a recovered hardwood flooring with a new one. 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 cumaru wood cabinet can be burned for biomass energy displacing coal or natural gas in generating electricity. 

With smaller household items, like door handles or knobs, 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. 

How Can You Buy Cumaru 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 cumaru 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. 

Water reclaimed cumaru timber is also a more sustainable option than timber cut from living old-growth cumaru trees. Many lakes throughout Central America were flooded to generate hydropower. That leads to a vast amount of tropical wood submerged underwater. Reclaiming such otherwise wasted timber to make furniture and flooring means less deforestation for human usage. 

Because there is a high risk of illegal or over logging for cumaru timber, only buy cumaru decking or furniture if you can be sure that the wood is sourced sustainably. 

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 made from cumaru wood as long as the material comes from sustainably managed forests. However, because cumaru is an imported tropical wood, it has a much higher transporting carbon footprint than hardwoods from temperate forests in the US. The widespread unsustainable logging in the Amazon Rainforest means you need to really check the source of the timber before buying your furniture or garden decking. Also, make sure you use any cumaru furniture for as long as possible, upcycle the material to extend its usage, and arrange for it to be recycled fully.

Stay impactful,

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