Construction of a Dicotomous Key for Common Local and Imported Timber Species in Sri Lanka
DOI:
https://doi.org/10.31357/fesympo.v18i0.1924Keywords:
Dicotomous key, Local timber, Imported timber, Scientific identificationAbstract
Proper timber identification mechanism is essential today than ever before as lesser knownlocal and imported timber species are coming to timber market in present. In Sri Lanka thereare over 400 different timber species of commercial use, which show a remarkably widerange of variation in their physical properties as well as their anatomical structures. Hencetimber identification is a highly important task to confirm its authenticity. Scientific woodidentification is based on microscopic evaluation of anatomical properties.
The objective is of this research is to develop a timber identification key for common localand imported timber species used in Sri Lanka to facilitate scientific identification of timberspecies based on anatomical features in IAWA (International Association of WoodAnatomist) list of 1989.
Timber samples of local and imported timber species were collected from various floristicregions in Sri Lanka. Authentic timber samples were collected from Research Division of theState Timber Corporation. Transverse section (T.S), Radial Longitudinal Section (R.L.S.) andTangential Longitudinal Section (T.L.S.) were obtained using the Microtome. Microscopicslides were prepared for sixty seven timber species and photographic representations andanatomical details were presented. Anatomical features of rays, parenchyma and vessels werestudied. Tangential vessel diameter and ray height were also measured. Values of the meanvessel diameter were categorized according to IAWA: category 1(<=50 μm), Category 2,(50-100 μm), Category 3 (100-200 μm) and Category 4 (>=200 μm).
The highest mean vessel diameter value was observed in Garcinia spp (Kandis) and secondhighest value was observed in Azadirachta indica (Margosa) timber species. The lowestMean Vessel Diameter value was observed in Elaeodendron glaucum (Neralu) timberspecies.
Specific gravity values were taken from previous research and publications. Specific gravityare categorized three categories according to IAWA features: low (<=0.40), medium (0.40 -0.75) and high (>= 0.75). The highest basic specific gravity value was observed in Diospyrosebenum (Ebony) (1.12) and second highest value was observed in Palu (1.1) timber species.The lowest basic specific gravity values were observed in Lunumidella and Rukattana timberspecies.
Mean ray height of 67 timber species were measured using Micrometrics SE premium 4software available at research division in the State Timber Corporation.
A dichotomous key on timber identification was prepared using 56 common local timberspecies and 11 major imported timber species mostly used in Sri Lanka to facilitate scientificidentification of timber species based on anatomical features of IAWA (InternationalAssociation of Wood Anatomist) List 1989.
