Imported lumber is typically accompanied by documents that state its geographic origin, so buyers can check that it wasn't illegally harvested from protected areas. Unfortunately, though, those documents can easily be forged. That's why Oregon-based scientists from the USDA Forest Service's Pacific Northwest Research Station have developed a method of determining where a piece of wood comes from, based on its unique chemical signature.

Led by Dr. Richard Cronn, the researchers used a technique known as DART-TOFMS (direct analysis in real time time-of-flight mass spectrometry). This allowed them to detect the presence and relative abundance of various chemicals in the annual growth rings of wood samples, which were taken from two populations of Douglas fir trees located in the Oregon Coast and adjacent Cascade mountain ranges.

The samples themselves were tiny, and could be made ready for analysis in 15 seconds. Upon analysis, it was found that while trees from within each population shared the same unique "chemical fingerprint," those fingerprints differed between the two populations, which were located less than 100 km (62 miles) apart.

It has yet to be determined if those differences are due to genetic factors, environmental factors, or a combination of the two.

So far, in comparing samples taken from 188 trees, the scientists were able to determine which of the populations each sample came from with an accuracy rate of 70 to 76 percent. That figure should likely improve as the technology is refined.

A paper on the research was recently published in the journal Applications in Plant Sciences.