A new study shows that combining chemical fingerprints and genetic markers in tropical hardwood can pinpoint a tree’s origin with precision, creating a powerful tool that can deter and potentially end ‘timber trafficking’—a racket that, according to INTERPOL, is the third most profitable cross-border crime after counterfeiting and drug trafficking.
Global researchers analysed genetic data, stable isotopes and concentrations of multiple trace elements from nearly 250 trees across 13 sites in Cameroon, Gabon and the Republic of the Congo, finding that the three lines of evidence together placed 94 per cent of samples within 100 kilometres of their true origin.
“This legislation requires that the exact origin of wood be reported when it enters the European market. But because of frequent fraud, authorities must also be able to independently verify the origin. For example, by analysing wood properties. Our research shows that this verification can be highly accurate when different wood properties are combined,” said Laura Boeschoten, a PhD graduate and one of the study’s lead authors.
The timing is significant: the EU’s Deforestation Regulation (EUDR) will require traders to demonstrate that timber imports are legal and not sourced from recently deforested land, creating strong demand for independent laboratory verification. The team focused on Lophira alata, commonly known as Azobé, a dense, durable hardwood widely used in heavy engineering and heavily traded from the Congo Basin. They created a reference database from heartwood and cambium samples taken at 13 logging sites. The researchers sequenced plastid single‑nucleotide polymorphisms to capture genetic structure, measured three stable isotopes that encode climatic signals, and quantified 41 trace elements that reflect local soil chemistry.
Individually, each method assigned samples to their origin at the 100‑kilometre scale between roughly 50 and 80 per cent of the time; when combined, the techniques boosted correct assignment rates into the mid‑90s, a leap with immediate enforcement implications. “Some wood properties are determined by conditions that differ only across large distances. Others vary more strongly between trees that grow close to each other. By combining them, the blind spots of one technique are compensated by the other two,” said Barbara Rocha Venâncio Meyer‑Sand, the co‑lead author of the study.
In plain terms, genetic data narrows broad geographic possibilities, elemental chemistry discriminates among local soils, and isotopes add climatic context; stacked together, they form overlapping signals that pinpoint origin more precisely than any single method.
The study evaluated both identification, which involves assigning an unknown sample to one of the 13 reference sites, and verification, which tests whether timber actually came from a claimed location. Results showed that combining all three methods produced the strongest verification performance, correctly confirming true claims in nearly 88 per cent of simulated tests and markedly improving the ability to reject false claims compared with single methods. Accurate lab‑based provenance, therefore, becomes a practical lever for exposing falsified paperwork and tracing laundering routes across supply chains.
“Combining techniques for origin determination is still in its infancy,” said Pieter Zuidema, professor at Wageningen University & Research and research leader on the project. “In recent decades, researchers have mainly focused on developing and promoting their own technique. We take a different approach: we compare and combine them. Of course, combining is costly and will in practice only be used for very valuable timber species or when the risk of illegality is very high.”
Authors acknowledge trade‑offs. Multi‑method testing carries higher costs and logistical demands, and geographic gaps remain in the current reference database—regions such as central Gabon and parts of the Democratic Republic of the Congo were not sampled. To strengthen operational readiness, the team recommends widening geographic coverage, adding nuclear DNA markers, expanding isotope panels and increasing elemental resolution.
The study grew from intensive collaboration with researchers based in the Congo Basin. “We provided training to them, conducted joint fieldwork and shared responsibilities. We truly achieved these results together,” said Rocha Venâncio Meyer‑Sand, highlighting the study’s capacity‑building component and the importance of local partnerships. If regulators, importers and enforcement agencies invest in expanded reference collections and interoperable testing frameworks, laboratory provenance could become a routine and effective response to a trade long haunted by falsified origins and illicit profit.
For further information: Boeschoten, L.E., Rocha Venancio Meyer-Sand, B., Boom, A. et al. Combined genetic and chemical methods boost the precision of tracing illegal timber in Central Africa. Commun Earth Environ 6, 789 (2025). https://doi.org/10.1038/s43247-025-02698-z
