Rethinking the Supply Chain to Save Endangered Trees

A Michigan Tech Forest Biomaterials researcher is working with the U.S. Army and the U.S. Forest Service to identify sustainable hardwood products for military trailers.

Apitong trees, native to Southeast Asian rainforests, have existed on Earth for more than 100 million years. Apitong trees can grow upwards of 200 feet tall, and one can imagine dinosaurs enjoying the leathery, prominently veined leaves for lunch. The tree’s flowers are palm-sized and starfish-like, their five petals tilted like a pinwheel in spin.

Southeast Asian rainforests are some of the most biodiverse areas of earth, with up to 1,200 different tree species per hectare. The beautiful and lofty Apitong trees, which include more than 40 subspecies of the Dipterocarpus genus, are also internationally recognized as critically endangered, with overharvesting threatening to soon end their eons-long tenure. The wood was incorrectly perceived by the Army and the commercial trailer industry as being resistant to rot and pests, a perception that has for decades made Apitong lumber the choice material for trailer decking and other applications. Virgin Apitong (also known as Keruing) stands are currently being clear-cut on a wide-scale — often illegally and with disregard to local indigenous peoples — to make way for palm oil monoculture plantations.

For some decades, the Army has relied on the wood from Apitong trees for trailer decking. The trailers are used to transport supplies, equipment and vehicles. Army trailer decks must be, in a word, rugged. The wooden decks are exposed to sun and heat, rain, microbes, insects, abrasion, rough roads and general abuse.

To reduce dependency on Apitong and promote ecosystem sustainability, the U.S. Army's Combat Capabilities Development Command (CCDC) Ground Vehicle Systems Center (GVSC) is working with Xinfeng Xie, assistant professor of forest biomaterials in the College of Forest Resources and Environmental Science (CFRES), and the U.S. Forest Service Forest Products Laboratory to identify different lumber products and treatments to use for trailer decking that are superior in resistance to biodeterioration.

“The strategy is to use domestic hardwood species from within the U.S. that have a commercially sustainable supply,” Xie said. “It will help the Army move away from using endangered species to achieve its global commitment to sustainability and environmental stewardship. A domestic hardwood product with enhanced durability will reduce the demand of Apitong wood.”

For its tactical trailers, the Army prefers to use wood rather than metal or composite for practical reasons, such as cost, strength and workability. Metal ammo or explosives containers transported on metal trailer beds could spark a fire or an explosion. Also, composite doesn’t have the high strength or ultraviolet resistance; composite decking exposed to sun in Arizona can disintegrate in a year. An added benefit of wood decking is that soldiers can nail directly into the wood to secure cribbing or dunnage for safer secured cargo transportation.

Apitong wood decking lasts only a small portion of the life span of the trailers’ steel frames; each trailer must be fitted with a new wooden deck several times during the life of the trailer. Domestic wood decking can be developed that could last at least half the life of the trailer frame, which would save taxpayers money and improve the Army’s readiness.

To determine which species of wood could best replace Apitong, Xie and his team are conducting durability and exposure testing at CFRES campus labs and CFRES Wood Protection Group sites in Hawaii, Florida and Louisiana. Numerous wood blocks are exposed at these locations and monitored to observe how the wood decays or whether termites damage the wood. In addition, a collaboration has been initiated with the Army Tropic Regions Test Center to conduct testing in Suriname and Panama, which provide extreme tropical environments to rapidly accelerate wood biodeterioration and to test prototype trailer bed floorboards. 

Xie’s work has numerous benefits.

“It’s a critical time to move the Army away from using Apitong,” he said. “And it’s also good for the U.S. hardwood industry and workforce. There’s a sustainable solution within this country.”

Xie said the Army uses approximately 1 million board feet per year for trailer decking, which is a level of demand that can be easily supplied sustainably from U.S. hardwood forests.

“I hope people think about the sustainability of the ecosystem and the environment. What we do can have a direct impact.”

Michigan Technological University is a public research university founded in 1885 in Houghton, Michigan, and is home to nearly 7,500 students from more than 60 countries around the world. Consistently ranked among the best universities in the country for return on investment, Michigan’s flagship technological university offers more than 120 undergraduate and graduate degree programs in science and technology, engineering, computing, forestry, business, health professions, humanities, mathematics, social sciences, and the arts. The rural campus is situated just miles from Lake Superior in Michigan's Upper Peninsula, offering year-round opportunities for outdoor adventure.