Australasian Science: Australia's authority on science since 1938

Forests Meet Forensics

By Stephen Luntz

Biometric checks of rainforest timbers entering a country could establish if wood from a region known to be logged unsustainably has been substituted.

Logging of rainforests has been banned in many regions of the world, but illegal logging continues apace. However, Adelaide University’s Centre for Evolutionary Biology and Biodiversity is making it much harder for the practice to continue.

“Molecular marker methods have been applied to freshly cut wood for a number of years, and it’s now also possible to extract and use genetic material from wood products and old samples of wood,” Prof Andrew Lowe says. “We can use DNA barcoding to identify species, DNA fingerprinting to identify and track individual logs or wood products, and we can also verify the region the wood was sourced from.”

DNA fingerprinting has been in use since 2007. This requires legal timber companies to take a genetic sample of the wood they have chopped down, and this is attached to a passport. As the wood makes its journey to become furniture or building materials, the sample can be verified to ensure that the wood is what it claims to be.

While passports alone are easily forged, Lowe says there have been no cases of attempted fraud detected in Australia for wood using the DNA fingerprinting as well. “It seems to be the ultimate deterrent,” Lowe says.

However, the cost of the paperwork and repeated testing is large, making it harder for sustainably logged wood to compete with wood from illegal sources. In the journal of the International Association of Wood Anatomists, Lowe has prefigured techniques that can be used to establish if wood comes from a tree in a specific region. Random checks of rainforest timbers entering a country could establish if wood from a region known to be logged unsustainably has been substituted.

Lowe says this technique has been used to identify merbau from parts of Indonesia where logging is considered unsustainable. Work is underway to map the DNA of valuable timbers from the Congo so that the source region of an assignment can be established.

Extending this process across the main rainforest species, as well as rarer timbers that are sometimes substituted for them, is part of a project known as “The Barcode of Life”. Over 5 years the project aims to produce a DNA barcode for every tree and grass species on Earth so that samples can be identified immediately.

Programs to combat illegal logging have proven highly effective in some regions, notably Brazil, but illegal timber operations are still thought to be worth billions of dollars per year, imperilling much of the world’s biodiversity as well as its climate.