Geographical traceability of an important tropical timber (Neobalanocarpus heimii) inferred from chloroplast DNA

The inbuilt unique properties of DNA within the timber could serve as tracking and monitoring tools to verify the legality of a suspected timber in the context of illegal logging, forest certification and chain of custody certification. By using Neobalanocarpus heimii (Dipterocarpaceae) as an example, a population identification database and haplotype distribution map in Peninsular Malaysia were generated for authenticity testing based on four chloroplast DNA markers (trnL intron, trnG intron, trnK intron and psbK-trnS spacer). Twenty one haplotypes were identified from 10 significant intraspecific variable sites. The results clearly revealed that only northern and southern regions of Peninsular Malaysia were distinguishable. Thus, this database could only be used to determine the wood lot of unknown origin at the regional level. Statistical procedure based on the composition of wood lot was used to test whether a suspected timber conforms to a given regional origin. Overall, the observed type I and II errors of the database showed good concordance with the predicted 5% threshold, which might indicate that the database is useful to reveal provenance and establish conformity of wood lot from northern and southern regions of Peninsular Malaysia. Applications of this database for timber tracking are discussed.