Tech for identifying species & origin

Technologies for species identification

Wood anatomy: This relatively simple method entails examining a cross section of the surface of a solid wood product using a handheld lens or microscope. The pattern of cells and pores can be compared with reference information to identify the genus or species. This method has significant limitations. How precise a judgement can be made depends on the level of variation between species and the availability of reference imagery. It can also be expensive, since it traditionally requires extensive time commitments from highly trained wood anatomists. Automated portable systems useable by non-experts have been designed, but are at an early stage of development and at present only applicable to a small range of wood species. Wood anatomy is also only possible for solid wood products.

Fibre analysis: Can be used for paper and pulp products, where individual wood fibres are examined under a microscope. Though it is rarely possible to distinguish down to the level of species using fibre analysis, it can be used to determine whether natural tropical forest wood is contained within a sample claiming to be made solely from plantation-grown wood.[1]

DNA analysis: Theoretically the most reliable method of species identification, but more expensive than wood anatomy. It is also dependent upon incomplete reference information, and on it being possible to extract useable DNA from a product.

Spectrometry: Potentially cheaper and easier than wood anatomy or DNA, this technology identifies the species based on how it reflects and absorbs different wavelengths of light. Reference databases for this methodology are even less well developed than for the others, however.

Establishing geographic origin

DNA analysis: Can in theory also be used to narrow down the geographic origin of a sample of a given wood species, based on natural variation in the DNA of individuals of a given species over its geographic range.

Stable Isotope Analysis: Uses the natural variation in the proportion of different versions of atomic elements such as carbon in individual wood samples, which varies along with the soil in which the trees grow.

Both methods hold great potential, but their applicability is restrained at present mainly by the absence of reliable reference databases of samples of known geographic origin. Even where such reference databases exist, they may not be of sufficient resolution to be able to determine geographic origin information of sufficient detail to be of use in establishing legality or illegality. The only example to-date of such databases being used in relation to legality is the use of isotopes to determine whether oak originates from the Russian Far East or neighbouring areas of China.[2]

DNA and isotope databases have also been developed for the most heavily-traded tropical wood species from Central and West Africa, though it appears that their resolution is only sufficient to at best determine country of origin.[3] Databases sufficient to demonstrate country of origin for a number of other major tropical wood species from Asia and Latin America, including Merbau[4], teak and mahogany[5] have also been developed. Whether DNA or isotopes can be used to reliably determine geographical origin more precisely, such as to an individual district or logging concession, remains an open question. Attempts to test the ability to use such databases to determine concession of origin of Merbau in Indonesia[6] and Iroko and Sapele in Cameroon[7] did provide some cause for hope, though the confidence levels obtained (around 70%) would be insufficient for prosecutions, and it is unclear whether the level of sampling needed to reach a more meaningful level of confidence is practicable.

At the time of writing, costs in the EU of species identification of a solid wood sample using wood anatomy were approximately US$100 – $200 per sample, DNA analysis around $300 – $700 per sample.[8] Isotopic tests to verify origin also cost around $200-$500 per sample. It can take anywhere from a few days to a few weeks to obtain results, depending on various factors.[9]

[1] Adam GrantRuth Nogueron and Craig Hanson, Q&A Fiber Testing-Paper and The Lacey Act, World Resources Institute blog, 2011 http://www.wri.org/blog/2011/01/qa-fiber-testing-paper-and-lacey-act

[2] EIA, ‘Liquidating the Forests: Hardwood Flooring, Organized Crime, and the World’s Last Siberian Tigers, 2013, http://eia-global.org/images/uploads/EIA_Liquidating_Report__Edits_1.pdf

[3] Degen, B. & Bouda, H., ‘Verifying timber in Africa’, ITTO Tropical Forest Update 24/1, 2015.

[4] Double Helix, The State of DNA Technology for Trees and Wood Products, 2011 http://www.illegal-logging.info/sites/default/files/uploads/DoubleHelixAppliedGeneticsForForestsReport072011.pdf

[5] Scheliha and Zahnen, Genetic and Isotopic Fingerprinting Methods – Practical Tools to Verify the Declared Origin of Wood, Deutsche Gesellschaft für Internationale Zusammenarbeit, 2010, Page 8

http://www.wwf.de/fileadmin/fm-wwf/Publikationen-PDF/Fingerprinting_conf_rep_EN.pdf

[6] Double Helix, The State of DNA Technology for Trees and Wood Products, 2011 http://www.illegal-logging.info/sites/default/files/uploads/DoubleHelixAppliedGeneticsForForestsReport072011.pdf

[7] Scheliha and Zahnen, Genetic and Isotopic Fingerprinting Methods – Practical Tools to Verify the Declared Origin of Wood, Deutsche Gesellschaft für Internationale Zusammenarbeit, 2010, Page 6

http://www.wwf.de/fileadmin/fm-wwf/Publikationen-PDF/Fingerprinting_conf_rep_EN.pdf

[8] Based on costs cited by the Thünen Institute on its website as of March 2016.

[9] Degen, B. & Bouda, H., ‘Verifying timber in Africa’, ITTO Tropical Forest Update 24/1, 2015.