The Chemical Fingerprint of Wood: Every Tree Reveals Its Origin
Where does the wood we use really come from? In a global context where the sustainable use of natural resources is increasingly urgent, answering this question is essential. Timber is a widely used raw material, and its illegal trade causes serious damage to ecosystems and biodiversity. Yet reliable tools to verify its geographical origin remain limited.
A new study, conducted by Eco Research in collaboration with the Free University of Bozen-Bolzano, explores a concrete and effective solution: an approach that combines multi-element and isotopic analyses with advanced statistical models. The investigation focused on three typical tree species from the Eastern Alps – Norway spruce, European larch, and Swiss stone pine – grown on diverse bedrock types.
The results are promising: each species shows a distinctive chemical fingerprint, and the strontium isotopic ratio reliably reflects the geology of the growing area. This enables high-precision identification of both species and origin of each sample. The study opens new perspectives for the application of these techniques by regulatory authorities to verify timber origin, or by producers themselves to support certified supply chains.
A B S T R A C T
International timber trading is subject to rigorous certification schemes that require the disclosure of essential information, including the tree species and geographic origin of the timber in question. Regrettably, the lack of readily accessible forensic tools to verify compliance has facilitated the proliferation of illegal timber trading, with dramatic consequences for ecosystems and biodiversity. The objective of this study was to investigate the potential of a multichemical approach based on the multielement and strontium isotope (87Sr/86Sr) ratio analysis combined with chemometrics to test sample recognition according to their species and geographic origin. The sampling area covered a regional-scale portion of the Eastern Alpine region (< 30 000 km2), for highlighting the applicability of the approach within a spatially constrained context. The study focused on three representative species from local forests: Norway spruce, European larch, and Swiss stone pine. Samples were characterised from stands grown on diverse bedrock types. Our findings revealed a strikingly consistent variation in the multielement profiles across different species, thereby enabling flawless sample recognition. Considering the geographic origin, the 87Sr/86Sr ratio proved to be a pivotal parameter, by virtue of its correlation with the geo-lithological composition of the growing area. Combining the chemical markers, an accurate sample classification based on multiple decision trees was attained, even comparing forest stands grown on the same bedrock type. These findings offer novel insights into the utilisation of chemical markers in provenancing and authenticity studies, thereby enhancing the adoption of integrated approaches to counteract illegal timber trade.