A proof-of-concept study: Determining the geographical origin of Brazilwood, (Paubrasilia echinata) with the use of strontium isotopic fingerprinting

The illicit exploitation of Brazilwood (Paubrasilia echinata) presents a significant challenge in Brazil, given its substantial value in the global production of bows for musical instruments. To address timber provenance, the use of strontium (Sr) isotope ratios as indicators of bedrock signatures has emerged as a robust tool in forensic investigations. In this study, we critically evaluate the efficacy of this approach using Sr isotope data derived from bulk soils and trees collected at two distinct sites in Brazil. Despite the statistically indistinguishable ⁸⁷Sr/⁸⁶Sr ratios observed in the investigated tree species, the compiled ⁸⁷Sr/⁸⁶Sr isotope ratios of Brazilwood from Brazilwood National Park (PNPB) and the ES Group provide valuable insights into the potential application of this method for tracing forensic timber seizures. This pilot study also addresses crucial sampling considerations.

While the regional signatures exhibit clear distinctions, the limited sample sizes underscore the necessity for supplementary methods to confidently attribute timber to a specific source forest. In isolation, this method proves most effective in refuting presumed timber provenances rather than definitively confirming them. The discussion delves into the nuances of the Sr isotope data, emphasizing the importance of increasing the number of samples and exploring complementary techniques for a more comprehensive and reliable assessment of timber origin.