Development of anatomical key for the identification of selected timbers of Kerala

Abstract

Deforestation poses a massive threat to global biodiversity with illegal logging and the associated trade in illegally sourced wood products. This is a significant contributor to the continuation of unsustainable deforestation rates. Reputed timber traders are also struggling to police their own supply chains and comply with the growing requirement for due diligence with respect to timber ongin and legality. A range of scientific methods have been developed independently with the potential to provide the required identification information. Wood anatomy is considered as a hi^y specialised science discipline which is used in combination with various technologies in forensic timber identification. Wood anatomical features are generally considered not prone to changes under normal circumstances and therefore it forms the basis of wood identification. Analysis can be undertaken at both the macroscopic and microscopic scale, but microscopic examination is usually required to achieve a diagnostic identification. Different features of interest in this scenario include cell size, arrangements of different elements, cell proportion and most importantly, specific gravity. There are thousands of species of trees fi:om which timber can be obtained, each with different rates of growth, structural properties and degrees of durability. Some timbers are highly decorative, some are very strong, some have good resistance to rot - in fact almost every species of wood has features that can be good in some uses, but not so good in others. Therefore, knowing what type of wood you have in fi-ont of you can be extremely important, either because you may have paid a lot of money for something you didn't actually get, or maybe because the wood you've got is unsuitable for the job you have in mind for it. Timber identification is a skill that must be gained with practice and with a bit of extra help from a skilled wood scientist. The lAWA (International Association of Wood Anatomists) List of Microscopic Features for Hardwood Identification is an important standardized list of characters and terminology that can be used in descriptive wood anatomical studies and identification obtained through comparison to reference materials.. The commonly used keys for wood identification are the dichotomous key, perforated card key and the computer aided identification key. Dichotomous keys are the most simple and easy to use keys. These types of keys have been used for over centuries in biological identification. The multiple entry perforated card type of key was introduced by the Forest Products Research Laboratory in 1936, when a key for the identification of hardwoods based on microscopic features was conducted. Hence, the preparation of anatomical key is very important in the field of wood industries for the identification of the suitable material or the tree. Anatomical keys of different timbers assists in a large way do away with the confusion in the identification of timbers. The anatomical keys can also support the molecular studies like DNA bar coding, molecular markers etc. Wood anatomical analysis is the most frequently used method for taxonomic identification, both on the front-line for screening purposes, and in the laboratory for diagnostic identification. In this study, 20 species of trees were considered in the preparation of anatomical keys for identification. The species of trees used for the study are Acacia auriculiformis, A. Cunn. Ex Benth. , Acacia mangium Willd.. , Albizia lebbeck (L) Benth. , Albizzia odoratissima (L.f) Benth. , Artocarpus heterophyllus Lamk. Artocarpus hirsutus Lamk. , Dalbergia latifolia Roxb. , Dalbergia nigra Fr All Hevea braziliensis (H. B. K.) M.A., Hopea parviflora. Bedd., Intsia bijuga (Colebr.) , Ocotea rodiaei (Schomb) Mez. , Peltogyne paniculata Benth. , Pterocarpus marsupium Roxb., Pterocarpus dalbergioides Roxb. ex DC., Santalum album Linn Swietenia macrophylla king. , Tectona grandis Linn. , Xylia dolabriformis Benth Xylia xylocarpa (Roxb.) Taub.