Forensic timber identification: a case study of a CITES listed species, Gonystylus bancanus (Thymelaeaceae)

Geographic origin and individual assignment of Shorea platyclados (Dipterocarpaceae) for forensic identification

“…Similar positive results were achieved for population assignment of Neobalanocarpus heimii , a dipterocarp timber species, to northern and southern regions of Peninsular Malaysia [24]. In addition, successful assignment has also been demonstrated in a CITES listed species, Gonystylus bancanus , to support forensic applications and help safeguard the species [19]. Apart from geographic origin assignment, DNA based verification can also function at the individual level.…”

“…wood anatomy: internal structure of wood at the macroscopic and microscopic level [10] and dendrochronology: the study of periodic growth increments formed in most temperate tree species [11]; (2) chemical methods, e.g. mass spectrometry: assessment of phytochemicals present in the heartwood [12], near infrared spectroscopy: the characterizations of wood absorption spectra [13], stable isotopes: chemical compounds synthesized by trees such as carbon, hydrogen, oxygen, nitrogen [14] and radiocarbon dating: the calculation of radiocarbon age based on the ratio 14 C and 12 C atoms [15]; (3) genetic methods: providing species level identification based on variation at specific gene regions [16], geographic origin identification using population genetics and phylogeographic analyses [17, 18] and individual level identification utilizing DNA profiles generated from molecular markers which can reveal variations between individuals [19–21]. …”

“…The application of DNA markers in timber tracking has been reported in geographic origin assignment [23, 24] and individual assignment [19, 21]. Geographic origin assignment is based on the ability to assign a sample to a particular population, requiring the source population to be sufficiently genetically distinct from other candidate populations and relying on the existence of population data from multiple areas [23].…”

“…By genotyping a broad enough set of reference database, it is possible to calculate the random match probability or the estimated frequency at which a particular STR profile would be expected to occur in a population [29] This random match probability is usually very small, e.g. goes beyond one in billions (10 9 ) [19] or trillions (10 12 ) [21], leading to the acceptance of DNA profiling as admissible evidence in court cases, where legal requirements are met. The DNA profiling technology has been used to verify intact chain of custody for Intsia palembanica in Indonesia [28], by matching samples taken at different points as they pass through the supply chain.…”

“…heimii [21] and G . bancanus [19] present opportunities for authority personnel to link wood material seized from suspects with the stumps of illegally felled trees.…”