SALEM — Logging thieves steal up to $1 billion every year from timberland owners but are up against a relatively new investigative tool — DNA tracing.

The U.S. Forest Service reported in September on advances by a team in Corvallis that has improved the forensic analysis of genetic material in cut logs.

It’s become more likely that the DNA of a tree can be matched against a growing database to show when and where a tree was felled.

Prior to scientific and legal developments over the past 15 years, prosecuting timber thieves was difficult. Unless caught in the act of felling a tree, the criminals could get the valuable wood into larger, legal lumber piles — sometimes convincing unwitting mill owners they were legally felled by using faked permits.

Once a log was removed, it could disappear into mills and lumberyards holding thousands of legally harvested trees.

Trees reveal their past

But a new system developed by researchers Rich Cronn and Laura Hauck at the U.S. Forest Service’s Pacific Northwest Research Station in Corvallis increases the chances of making charges stick.

Using DNA taken from a fallen tree, the researchers developed ways to test wood products that have recently been accepted by federal courts and are admissible evidence.

The U.S. Department of Justice used the system to convict an illegal harvester of big-leaf maple trees in the Olympic National Forest in Washington state.

A key development was the extension of the 122-year-old Lacey Act, approved by Congress in 1900 to prosecute poachers and sellers of illegally obtained wildlife and fish. In 2008, the Lacey Act was amended by Congress to include the illegal harvesting and selling of trees and other plants.

The system created by the Corvallis researchers was able to show the big-leaf maples trees in question had been cut between April and August 2018 in an area near Elk Lake in the Olympic National Forest where logging was not allowed.

At the end of the illegal harvesting, a fire started burning in the area, destroying a swath of forest where the trees had been cut.

The investigation, and later statements by the illegal harvesters, indicated the thieves found a large wasp nest at the base of a tree. In an attempt to kill the stinging insects, the thieves had poured gasoline or herbicide on the nest. The liquid ignited, eventually growing over four months to a fire that burned more than 3,000 acres before it was extinguished in November 2018.

Research geneticists with the U.S. Department of Agriculture tested three trees near where the fires began and found they were more than 99% identical to lumber that federal agents had located at a mill in Tumwater, Washington.

The mill owner showed the federal agents the permit’s seller — Justin Andrew Wilke — had shown to authenticate that the lumber had been legally harvested. An analysis found the permits were forged.

At Wilke’s trial, a research geneticist for the U.S. Agriculture Department’s Forest Service testified that the wood Wilke sold was a genetic match to the remains of three poached maple trees that investigators had discovered in the Elk Lake area.

A jury in Tacoma convicted Wilke, who was sentenced to 20 months in prison.

“When people steal trees from our public lands, they are stealing a beautiful and irreplaceable resource from all of us and from future generations,” Tessa Gorman, the U.S. attorney prosecuting the case, said after the verdict.

Widening the genetic dragnet

Part of the ongoing effort is a larger, more specific database showing when and why trees grew at a specific location. Researchers work with law enforcement records, non-governmental organizations involved in forest management and preservation, and input from “citizen scientists” to crowdsource data.

Together, they are building genomics databases for the species most frequently targeted by timber thieves.

Like humans, tree DNA passes traits on to the next generation of trees. Trees can be part of the original natural landscape, brought by early settlers from other parts of the country or overseas.

Lumber has increasingly used “farmed” trees planted for the specific purpose of being harvested after a set number of years.

Trees, like other plants, have been genetically modified by scientists to make them more resistant to pests and diseases, as well as more resistant to the herbicides that can be used in farms and forests or spread via groundwater.

The genetic changes can make trees larger and stronger, and enable them to cope with different climate areas.

Specific DNA changes can be seen in different geographic areas, enabling forensic foresters to narrow down where and when the trees were planted.

The new system can determine if trees are clones of one original tree. They can catalog seed collections and when and where they have been used.

There are large areas in Oregon that were reforested with specific genetic modifications during massive reforestation efforts using trees from beyond Oregon.

By the 19th century, wildfires were being mapped, such as the “Great Fire” of 1845 at Mount Hebo, on the border of Tillamook and Yamhill counties. The Tillamook burns charred 355,000 acres during six fires between 1933 and 1952.

The Oregon Historical Society published a compendium of known major fires in western Oregon and western Washington in December 1935.

Many of the earliest major fires were recorded in the coastal ranges, which were more heavily settled than the Cascades or Eastern Oregon. These areas were more likely to hit homes and structures and also generate reports that would arrive in Salem, Portland or Washington, D.C.

A severe drought in 1910 led to a series of major blazes from just east of Portland to the eastern slope of Mount Hood and the Limpy Creek blaze near Grants Pass

Where the fires did and did not burn, what trees were planted and when, plus additional ability over time to genetically modify trees are all markers that can determine if a log was located in an area where timber harvesting is authorized or a place where thieves might have illegally cut down trees.

Science Findings is a publication of the U.S. Department of Agriculture and U.S. Forest Service. Find Pacific Northwest articles at www.fs.usda.gov/pnw.

Information on using tree DNA to go after timber thieves was covered in a U.S.Department of Agriculture public report, www.fs.usda.gov/pnw/sciencef/scifi250.pdf.