- Investigators used a tree's genes to match it to lumber sold by poachers.
- There are over 60,000 tree species in the world, all genetically different.
- Special-figured maple wood is valued by musical instrument makers.
For the first time ever, investigators have used tree DNA as evidence in court—to help convict a wood poacher.
In July 2021, Justin Andrew Wilke was convicted of conspiracy, theft of public property, depredation of public property, trafficking in unlawfully harvested timber, and attempting to traffic in unlawfully harvested timber, according to a statement from the U.S. Attorney's Office for the Western District of Washington. Earlier this month, he was sentenced to 20 months in prison for his role in poaching maple trees from the Olympic National Forest.
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These trees are especially valuable because they're used to make musical instruments like guitars, clarinets, and piano parts. The most coveted musical maples have special marks, called "figuring," that indicate they're of higher value for musical use. There are several types of figured maple, all with distinctive patterns.
"[Washington's] Olympic National Forest is known for its towering, lush, and wide-trunked trees," The Washington Post reports. "The bigleaf maple is among the more prized inhabitants—its patterned wood is often coveted for woodworking and manufacturing musical instruments. But it is illegal to chop down trees in national forests without a permit." The thefts cost a reported $100 million a year in damages and work hours.
Court documents describe how Wilke and his co-conspirator Shawn Edward Williams snuck onto public lands in Washington state in the summer of 2018. The two men cut down the trees, then cut them into rounds that were easier to lug out of the woods. (You can't exactly back up your legitimate logging rig to the place where you just stole public trees.) The courts estimated that Wilke made up to $7,000 by selling the stolen wood using forged papers.
The cool news here is that genetic information from trees allowed them to fight back against the thieves. Richard Cronn, a research geneticist for the Agriculture Department's Forest Service, showed in court that the sold lumber matched the remains of the three chopped trees. Prosecutors said the likelihood of a false positive was one in an undecillion—a one followed by 36 zeros. (Undecillion is from the Latin for "eleven," meaning one thousand followed by eleven more sets of three zeroes.)
It may sound strange that tree genes can be used in court, but plants are made of cells that contain genetic information just like humans and animals. Plant cells are set apart by qualities like their cellulose cell walls, but otherwise we have more in common than not.
So how are trees differentiated by their genes? Different species have different genes, unlike cat or dog breeds, which are all the same species, but with different characteristics. There are over 100 species of maple trees, alone, each with their own special genes. The most iconic maple tree, the sycamore maple, is species Acer pseudoplatanus in family sapindaceae. Compare that with the ginkgo tree, Ginkgo biloba, from the now almost-extinct family ginkgoaceae. You have to go back nearly to the kingdom level to find where these two leafy trees branch apart.
All of this makes trees a great fit for genetic study in general, and for genetic identification in cases like Wilke's. It's easy to see how the tree geneticist could be so sure these two trees were the same, based on the special fingerprints of each specimen across the 60,000 tree species around the world.