Anatomical and Physico-mechanical Characterization of Narra (Pterocarpus indicus Willd.) Branchwood Collected in Mount Makiling Forest Reserve, Laguna, Philippines

Rosalie C. Mendoza1*, Vivian C. Daracan1, Ronniel D. Manalo1,
Chelle Hennessy R. Batallones1, Kisses G. Jaurigue2,
Arlene D. Romano1, and Willie P. Abasolo1

1Department of Forest Products and Paper Science, College of Forestry
and Natural Resources, University of the Philippines Los Baños,
College, Los Baños, Laguna 4031 Philippines
2MSA Academic Advancement Institute, Esteban cor. Dela Rosa,
Legazpi Village, Makati City 1229 Philippines

*Corresponding Author: This email address is being protected from spambots. You need JavaScript enabled to view it.




The properties of narra (Pterocarpus indicus Willd.) branchwood collected from Mount Makiling Forest Reserve (MMFR), Los Baños, Laguna, Philippines were studied. These branchwood properties were also compared with narra stemwood’s experimental and published properties. Core samples of stemwood were taken for anatomical characterization while branchwood samples were taken for anatomical (area percentage of fiber and parenchyma cells, fiber morphology, and computation of fiber indices), physical (moisture content, density, specific gravity, and shrinkage), and mechanical (static bending and compressive strength) analysis. Results showed that narra branchwood exhibits similar anatomical features to narra stemwood. Branchwood, however, has smaller pores, abundant inclusions, and less distinct storied arrangement of wood rays than stemwood. The area percentage of fiber cells is higher in stemwood while parenchyma percentage is higher in branchwood. Fiber dimensions appeared to be statistically the same for stemwood and branchwood, except for fiber length. Computed fiber indices of narra branchwood are also within the standard value ranges. In terms of mean density and specific gravity at 12% moisture content of the branchwood were 0.70 g/cm3 and 0.66, respectively. Mean tangential, radial, and longitudinal shrinkages were 3.59%, 3.37%, and 0.6%, respectively; while volumetric shrinkage was about 6.35%. The static bending properties of branchwood were not different from stemwood. The mean modulus of elasticity and modulus of rupture were 9.92 GPa and 96.59 MPa, respectively. On the other hand, the compressive strength parallel to the grain was lower at 32.64 MPa.  Thus, narra branchwood may be used as a substitute for narra stemwood in various uses such as for high-grade furniture and cabinetry, musical instruments, pulp and paper, production of novelty items, and wood parquet.



Wood is one of the most used renewable raw materials and the main source of livelihood of the people belonging to the forest products sector. As a structural material, wood can be used in many forms of construction. In the Philippines, the demand for wood and other timber products has increased over the years. Guiang (2001) stated that several studies show that the existing domestic wood supply from natural and plantation forests is insufficient to meet the increasing domestic demand.
The timber industry has a significant contribution to the national economy, but its operation is not sustainable. Material wastage is one of the major problems of the timber industry. It is reported that nearly 50% of the tree volume is left in the forest to decay. These are in the form of branches, crown wood, and stumps (Adam et al. 1993, as cited by Okai et al. 2003). Hence, there is a continuous effort to explore the utilization of other sources of wood to sustainably meet the soaring demand for timber and other forest products. The utilization of branchwood of high-value forest crops (HVFC) could be one of the potential sources of wood raw materials and could be used as an alternative to stemwood. Unfortunately, limited studies have been reported on the properties of HVFC utilized in the Philippines. . . . read more




ADAM AR, OFOSU-ASIEDU A, DEI AMOAH C, ASANTE ASIAMAH A..1993. Wood waste and logging damage in Akuse and Afram Headwaters Forest Reserve. Report of ITTO Project PD 74/90. Better utilization of tropical timber resources in order to improve sustainability and reduce negative ecological impact, FORIG, Kumasi. p. 46–51.
AL-SAGHEER NA, DEVI PRASAD AG. 2010. Variation in wood specific gravity, density and moisture content of Dipterocarpus indicus (Bedd.) among different populations in Western Gats of Karnataka, India. International Journal of Applied Agricultural Research. 5(5): 583–599.
ALIPON MA, BONDAD EO. 2008. Strength grouping of Philippine timbers for various uses. Forest Product Research and Development Institute. College, Laguna, Philippines.
AMOAH M, DADZIE PK, FRIMPONG-MENSAH K, SHI SQ. 2015a. Comparison of density and selected microscopic characteristics of stem and branch wood of two commercial trees in Ghana. Wood Science and Technology 50(1): 91–104.
AMOAH M, BOAMPONG E, DADZIE PK, FRIMPONG-MENSAH K. 2015b. Effect of density and moisture content on biological durability of stem and branch wood of Entandrophragma cylindricum (Sapele). Journal of the Indian Academy of Wood Science 12(1): 44–53.
ANTWI-BOASIAKO C, APREKO-PILLY S. 2016. Termite resistivity of the stem and branch woods of Aningeria robusta and Terminalia ivorensis. African Journal of Wood Science and Forestry 4(2): 231–237.
[ASTM] American Society for Testing and Materials. 2014. D143-14, Standard Test Methods for Small Clear Specimens of Timber. West Conshohocken, PA.
BAAS P, WHEELER E, GASSON P eds. 1989. IAWA list of microscopic features for hardwood identification. IAWA Journal 10(3): 221–358.
BHAT KM, BHAT KV, DHAMODARAN, TK. 1985. Wood and bark properties of branches of selected tree species growing in Kerala [KFRI Research Report 29]. Kerala Forest Research Institute Peechi, Thrissur.
BHAT KM, BHAT KV, DHAMODARAN TK. 1989. Fibre length variation in stem and branches of eleven tropical hardwoods. IAWA Bull. n.s. 10(1): 63–70.
BOWYER L, SHMULSKY JR, HAYGREEN GJ. 2003. Forest Products and Wood Science: An Introduction, Fourth Edition. Ames, IA: Blackwell Publishing Professional.
CABANGON RJ. 2006. Philippine woods for decorative veneer and plywood. Forest Product Research and Development Institute. College, Laguna, Philippines.
DADZIE PK, AMOAH M. 2015. Density, some anatomical properties and natural durability of stem and branch wood of two tropical hardwood species for ground applications. European Journal of Wood and Wood Products 73(6). 10.1007/s00107-015-0925-x.
DADZIE PK, AMOAH M, FRIMPONG-MENSAH K, OHENEBA-KWARTENG F. 2016. Some physical, mechanical and anatomical characteristics of stemwood and branchwood of two hardwood species used for structural applications. Materials Structures 49(12): 4947–4958.
DROZDZEK M, HORODENSKI J, JANKOWSKA A, SARNOWSKI P. 2017. Effect of extractives on the equilibrium moisture content and shrinkage of selected tropical wood species. BioRes 12(1): 597–607.
GUIANG ES. 2001. Impact and effectiveness of logging bans in natural forests: Philippines. In: Forests out of bounds: Impacts and effectiveness of logging bans in natural forests in Asia-Pacific. Durst PB, Waggener TR, Enters T, Cheng TL eds. Food and Agricultural Organization of the United Nations. Regional Office for Asia and the Pacific, Bangkok, Thailand.
ECKBLAD JW. 1991. How many samples should be taken? Bioscience 41(5): 346–348.
FRANKLIN GL. 1945. Preparation of thin sections of synthetic resins and wood-resin composites, and a new macerating method for wood. Nature 155(3924): 51–59.
GURAU L, CIONCA M, MANSFIELD-WILLIAMS H, SAWYER G, ZELENIUC O. 2008. Comparison of the mechanical properties of branch and stem wood for three species. Wood and Fiber Science 40: 647–656.
HAKKILA P. 1989. Utilisation of residual forest biomass. Berlin: Springer Verlag. 568p.
INSIDEWOOD. n/d. InsideWood Database. Retrieved from on 20 Sep 2019.
JANG HF, SETH RS. 1998. Using confocal microscopy to characterize the collapse behavior of fibers. Tappi J 81: 167–174.
KIAEI M, ROQUE RM. 2015. Physical properties and fiber dimension in stem, branch and root of alder wood. Fresenius Bulletin 24(1b): 335–342.
OKAI R, FRIMPONG-MENSAH K, YEBOAH D. 2003. Characterization of moisture content and specific gravity of branchwood and stemwood of Aningeria robusta and Terminalia ivorensis. European Journal of Wood and Wood Products 61(2): 155–158.
SAMARIHA A, KIAEI M, TALAEIPOUR M, NEMATI M. 2011. Anatomical structural differences between branch and trunk in Ailanthus altissima wood. Indian Journal of Science and Technology 4(12): 1676–1678.
SAN HP, LONG LK, ZHANG CZ, HUI TC, SENG WY, LIN FS, HUN AT, FONG WK. 2016. Anatomical features, fiber morphological, physical and mechanical properties of three years old new hybrid Paulownia: Green Paulownia. Research Journal of Forestry 10: 30–35.
STOKKE DD, MANWILLER FG. 1994. Proportions of Wood Elements in Stem, Branch, and Root Wood of Black Oak (Quercus veluntina). IOWA State University Forestry Publications.
TSOUMIS G. 1968. Wood as raw material. Oxford: Pergamon Press.
VURDU H, BENSEND DW. 1980. Proportions and types of cells in stems, branches and roots of European black alder (Alnusglutinosa L. Gaertn.). Wood Sci 13(1): 36–40.
WIEDENHOEFT AC. 2013. Structure and function of wood. In: Handbook of Wood Chemistry and Wood Composites, 2nd Edition, Chapter 2. p. 9–32.
WILSON K, WHITE DJB. 1986. The Anatomy of Wood: Its Diversity and Variability. London: Stobart and Son Ltd. p. 1–316.
WHEELER, EA. 2011. InsideWood – a web resource for hardwood anatomy. IAWA Journal 32 (2): 199–211.
YAMAN B. 2014. Anatomical differences between the stem and branch wood of Ficus carica L. subsp. carica. Modern Phytomorphology 6: 79–83.