WOOD FIBER MORPHOLOGY OF TALISAY-GUBAT (Terminalia foetidissima Griff.) AND LANIPAU (Terminalia copelandii Elmer.) GROWN IN MAGUINDANAO, PHILIPPINES

ARTICLE HIGLIGHTS
- The study examined Terminalia foetidissima and Terminalia copelandii, native Philippine species that remain underutilized due to limited data despite their strong potential for the wood industry.
- Wood characterization helps evaluate their fiber properties and potential contribution to meeting increasing wood demand.
- The research focused on fiber morphology and derived values of both species grown in Maguindanao, Philippines.
- The findings provide reliable baseline data on the basic wood characteristics of these two native Terminalia species.

ABSTRACT
Talisay-gubat (Terminalia foetidissima Griff.) and Lanipau (Terminalia copelandii Elmer.) are among the Terminalia spp. native in the Philippines. The fiber morphology and derived values of the two species were characterized in this study. Wood samples were collected from matured trees (approximately 10 to 20-yr-old) grown in Maguindanao del Norte (07°08′N 124°16′E). Collected samples were macerated for three-hours, wood fibers were observed under a microscope and then measured using the ImageJ Software. Results showed that T. foetidissima wood exhibited larger fiber diameter (0.041mm), and lumen diameter (0.028mm) with higher flexibility ratio (71.727%). While T. copelandii exhibited longer fiber (1.677mm) with higher cell wall fraction (33.688%), Runkel ratio (0.598), slenderness ratio (51.510), Mulhsteph ratio (51.813%), rigidity coefficient (0.163), and Luce’s shape factor (0.390). Moreover, t-test analysis showed no significant differences in the fiber morphology and derived values. The results indicated that both T. foetidissima and T. copelandii fibers show favorable qualities for pulp and paper production and composite materials. To fully confirm their potential and suitability, however, it is essential to examine other wood properties, including physical, mechanical, and chemical characteristics, as well as factors such as diameter and age classes, height levels, and wood types.

INTRODUCTION

The Philippine wood industry displayed great potentials and capabilities, in consideration with the abundance of the endemic and native tree species thriving in the country as potential source of raw materials. However, many species were not yet studied or have limited data resulting in improper and limited utilization. Also, road expansion, site reclamation, and other forms of urbanization, coupled with a lack of awareness and appreciation, are some of the contributing factors for rapid disappearance of Philippine native trees (Senga, 2019). Among those native tree species are Talisay- gubat (Terminalia foetidissima Griff.) and Lanipau (Terminalia copelandii Elmer), both Terminalia species under the family Combretaceae. Genus Terminalia is considered the second largest genus under Combretaceae family that comprises about 250 species of large to very large trees that are widely distributed in the tropical and subtropical regions of the world. Generally, Terminalia spp. provides economical, medicinal, spiritual and social benefits. Its wood is highly appreciated for constructional timber (Singh et al., 2013); (Akinsulire et al., 2018).

In the island of Mindanao, Philippines, many native tree species were lesser-used due to limited information and promotion, although they may hold enormous potential not only in wood-based industries but also in conservation and biodiversity. Moreover, T. foetidissima and T. copelandii are among the tree species naturally and abundantly thriving in the area. T. foetidissima is native to the Philippines and to several countries in Southeast Asia, such as Myanmar, Thailand, Malaysia, and Indonesia. It is the counterpart of Talisay in the inland, found in higher elevations characterized as a large, deciduous tree growing up to 45 m tall and 80 – 100 cm diameter. Usually, it is used as a dye and as a source of wood for construction purposes and furniture making (Ragasa et al. 2019; (Malabrigo & Umali, 2022)). Like T. foetidissima, T. copelandii is native to the Philippines, Southeast Asia, and various tropical regions around the world under the same family. It can grow up to 30 – 45 m tall and 70 – 80 cm diameter, characterized as a medium-sized tree with a straight, cylindrical bole that dominates the freshwater swamp forests in the country (Malabrigo & Umali, 2022); (Fern, 2022). Under the (I.U.C.N., 2025), both T. foetidissima and T. copelandii were classified as least concern species (I.U.C.N., 2025).

Several studies were documented on the wood anatomical properties of some Terminalia spp. such as T. catappa (Aina et al. 2019) in Nigeria, and T. arjuna, T. belerica, T. chebula, and T. myriocarpa in India (Singh et al., 2013). Also, a study about the leaf and petiole anatomical characters of T. catapa, T. superba, T. ivorensis, T. mantaly, and T. avicennioides was conducted (Akinsulire et al., 2018). In the Philippines, wood properties of T. foetidissima were characterized along with other lesser-used species (F.P.R.D.I., 1996). However, no records yet for T. copelandii have been found about its wood properties, particularly in the Philippines. This lack of data on the wood properties of both T. foetidissima and T. copelandii in the country resulting to their improper and lesser utilization. Studies on this matter would be of great opportunity to unlock the potentials of these species considering variations ascribed from vital factors like geographic location, species- specific properties, etc.

The proper wood characterization of T. foetidissima and T. copelandii will be beneficial to further assess its fiber properties whether it could significantly fill the limited supply and contribute to the increasing demand of the wood industry in the country. This is to consider the Philippine government declaration for a moratorium on the cutting and harvesting of timber in the entire country's natural and residual forests under (Philippines, 2011) that relatively limits the wood supply, yet controls the abusive utilization of the forest resources.

Wood fibers are the principal element that is responsible for the strength of wood. Therefore, this study emphasized the characterization of fiber morphology and derived values of T. foetidissima and T. copelandii wood grown in Maguindanao Province, Bangsamoro Autonomous Region in Muslim Mindanao (BARMM), Philippines. This study also provided further reliable knowledge on the basic characteristics of two Terminalia spp. native in the country, which would be vital for proper utilization, especially for the least concern tree species thriving in BARMM region.

MATERIALS AND METHODS

Plant Materials and Wood Samples Collection

The wood samples of T. foetidissima and T. copelandii were collected at the Maguindanao del Norte (07°08′ N; 124°16′ E), BARMM, Philippines, with an elevation ranging from 85-110 meter above sea level (masl) Figure 1, displaying a tropical monsoon climate (Classification: Am).

Three matured trees (approximately 10 to 20-year-old) were selected per tree species with a diameter of greater than 20 cm. Wood samples were extracted at three different locations within the DBH level (1.3 m) of the trees which were free from defects, knots, and injuries, using a 5.15 mm diameter by 100 mm long alloy steel increment borer, with a fine-threaded tip. After extraction, wood samples were placed in the respective ziplock bags with proper labelling for safe keeping, while the holes in the trees caused by increment borer were patched with wood and painted to keep away from the degrading organism (i.e., insect and fungi).

Figure 1.Location of the collected T. foetidissima and T. copelandii wood samples in Maguindanao, Philippines

Wood Maceration

Matchstick-sized samples were prepared from the collected wood samples and then macerated in equal volume (1:1) of acetic acid and hydrogen peroxide (50% concentration), following the procedure of (Espiloy et al., 1999). The maceration was done in a water bath and heated for three hours at 100 oC until the samples became white, soft and easy to separate into individual fibers. Afterward, the samples were washed with distilled water to become acid-free, and then subjected to microscopic observation and measurement without staining.

Fiber Measurement

Before fiber measurement, the macerated samples inside the test tubes were shaken to ensure the separation of different structural elements. Twenty-five undamaged fibers were observed per replicate under the Euromex compound microscope and measured using ImageJ Software (ImageJ 1.45). The length, diameter, and lumen diameter of each fiber were measured in accordance to the International Association of Wood Anatomists (IAWA) standard (Wheeler et al., 1989), while the cell wall thickness was determined based on the difference between the fiber diameter and lumen diameter. Cell wall fraction (1) was also calculated following the equation used by (Eloy et al., 2024):

Cell wall fraction = 2 x Cell wall thickness x 100 (1)

Fiber diameter

Derived Values

Based on the fiber morphology data, the derived values such as Runkel ratio (2), Slenderness ratio (3), Flexibility ratio (4), Muhlsteph ratio (5), and Rigidity coefficient (6) were computed using the equation used by (Hartono et al., 2022), while the Luce’s shape factor (7) was determined using the equation followed by (Wood properties related to pulp and paper quality in two Macaranga species naturally regenerated in secondary forests, 2016). These values were used to further evaluate the potential of T. foetidissima and T. copelandii as raw materials for pulp and paper production, and other applications.

Runkel ratio = 2 x Cell wall thickness (2)

Lumen diameter

Slenderness ratio = Fiber length (3)

Fiber diameter

Flexibility ratio = Lumen diameter x 100 (4)

Fiber diameter

Mublsteph ratio(%) = Fiber diameter² - lumen diameter² x 100 (5)

Fiber diameter²

Rigidity coefficient = Cell wall thickness (6)

Fiber diameter

Luce' s shape factor = Fiber diameter² - Lumen diameter²(7)

Fiber diameter² +Lumen diameter²

Statistical Analysis

A t-test analysis was used to compare the fiber morphology and derived values of T. foetidissima and T. copelandii wood. This analysis was carried out using Jamovi version 2.3 (Jamovi Project 2023).

RESULTS AND DISCUSSION

Fiber Morphology of T. foetidissima and T. copelandii

The statistical description (mean and standard deviation) and the result of the t-test analysis on the fiber morphology of the T. foetidissima and T. copelandii were presented in Table 1, while sample photos of the wood fibers are displayed in Figure 2.

Table 1.Fiber morphology of T. foetidissima and T. copelandii wood species

Property	T. foetidissima	T. copelandii	Significant level of difference (P-value)
Fiber length (mm)	1.613	1.677	0.668ns
	(±0.136)	(±0.198)
Fiber diameter (µm)	41.345	34.992	0.307ns
	(±0.005)	(±0. 008)
Lumen diameter (µm)	28.296	23.495	0.402ns
	(±0.005)	(±0.007)
Cell wall thickness (µm)	6.524	5.748	0.189ns
	(±7.51e-4)	(±3.79e-4)
Cell wall fraction (%)	31.842	33.688	0.691ns
	(±5.003)	(±5.567)

Figure 2.Photos of T. foetidissima (left) and T. copelandii (right) wood fibers

Fiber Length

Results of the study showed that the fibers of T. foetidissima and T. copelandii measured 1.613 mm and 1.677 mm, respectively. The analysis indicated no significant difference in fiber length between the two species, with a P-value of 0.668, suggesting that the fiber lengths are comparable. The average fiber length results of the present study were relatively longer compared to other Terminalia spp. like T. arjuna (1.176 mm), T. bellerica (1.131 mm), T. myriocarpa (0.991 mm) in India (Singh et al., 2013), T. ivorensis (sapwood, 1.314 mm & heartwood, 1.413 mm) in Ghana (Antwi-Boasiako & Apreko-Pilly, 2016), T. arjuna (0.512 mm), T. bellerica (0.262 mm), T. chebula (0.445 mm), and T. elliptica (0.490 mm) in India (Ranjan et al., 2025). These findings were relatively comparable to the fiber length of T. foetidissima (1.650 mm) in Philippines (F.P.R.D.I., 1996) and T. catappa (1.673 mm) in Nigeria (Aina et al. 2019). Compared to some underutilized native wood species in the Philippines (Villareal et al., 2025) such as Alstonia scholaris (1.79 mm), Ficus callosa (1.82 mm), and Ficus variegata (2.73 mm), both T. foetidissima and T. copelandii possessed shorter fibers, except for Broussonetia luzonica (1.44 mm). Moreover, T. foetidissima and T. copelandii fibers were relatively longer than the fibers of Falcataria moluccana (3-, 5-, and 7-year-old trees: 1.160, 1.140, and 1.170 mm, respectively), a fast-growing plantation species in the country commonly used for veneer, plywood, pulp and paper, and other light construction applications (Alipon et al., 2021).

(Salehi, 2001) grouping, both the fibers of T. foetidissima and T. copelandii fall under the second group, which is characterized by having an average fiber length ranging from 0.9 to1.9 mm. These results indicate that the fibers of T. foetidissima and T. copelandii could befavorable raw materials for composite products considering that fibers ranging from 1.0 to 5.0 mm in length can potentially be used for composite products (Madsen et al., 2013). Long fibers with thin cell walls were much preferable for pulp and paper manufacturing since thelongerthe fiber, the higher the paper's tearingresistance (Sharma et al., 2011). (Suansa & Al-Mefarrej, 2020) also stated that fibers with an average of greater than 0.4mm are considered suitable raw materials for papermaking. Based on the fiber length results,T. foetidissima andT. copelandiifi bers would befavorable for pulp and paper production. Additionally, the DENR Administrative Order No.2000-63 also classifies both species as suitable materials for furniture and construction applications. However, further research is needed to thoroughly evaluate the potential of these species for various applications

Fiber and Lumen Diameter

The findings of this study revealed that the T. foetidissima fiber diameter was 41.345 µm, while T. copelandii fiber diameter was 34.992 µm. Statistical analysis revealed no significant difference in the fiber diameter between these two species, with a P-value of 0.307. The average fiber diameter of T. foetidissima and T. copelandii was relatively smaller than those of Terminalia spp. reported by (Singh et al., 2013) such as T. arjuna (160.40 µm),T. bellerica (171.00 µm), T. chebula (125.40 µm) and T. myriocarpa (256.90 µm) (Singh et al., 2013), but larger to T. foetidissima (27.00 µm) (F.P.R.D.I., 1996) and T. ivorensis (sapwood, 21.69 µm and heartwood, 19.79 µm) (Antwi-Boasiako & Apreko-Pilly, 2016). Moreover, the observed fiber diameter of T. catappa (36.37 mm) (Aina et al. 2019), and 3-, 5-, and 7-year-old F. moluccana (35.40, 37.40, and 38.00 µm) (Alipon et al., 2021) were comparable to the present results. Compared to some underutilized native species reported by (Villareal et al., 2025), the fiber diameters of T. foetidissima and T. copelandii were smaller than A. scholaris (49.50 µm), F. callosa (52.83 µm), and F. variegata (52.13 µm), except for B. luzonica (35.83 µm).

Relative to lumen diameter, the results showed that T. foetidissima fiber has an average lumen diameter of 28.296 µm and T. copelandii fiber has a lumen diameter of 23.495 µm. The analysis revealed no significant results with a P-value of 0.402, indicating a comparable result for the lumen diameter of T. foetidissima and T. copelandii fibers. The average lumen diameters of T. foetidissima and T. copelandii were relatively larger than those of T. foetidissima (17.00 µm) (F.P.R.D.I., 1996), T. ivorensis (sapwood, 15.47 µm & heartwood, 13.33 µm) (Antwi-Boasiako & Apreko-Pilly, 2016), T. catappa (10.00 µm) (Aina et al. 2019). Compared to the findings of (Villareal et al., 2025) on A. scholaris (38.73 µm), F. callosa (37.40 µm), and F. variegata (33.07 µm), both T. foetidissima and T. copelandii fibers’ lumen diameter were smaller, except for B. luzonica (26.33 µm). Moreover, (Alipon et al., 2021) report larger lumen fibers of 5 and 7-year-old F. moluccana with 30.90 and 31.70 (µm), respectively, while 3-year-old F. moluccana seems to be comparable to T. foetidissima fiber. Basically, the lumen diameter significantly influences the beating process of pulp and paper production, as liquid penetrates the empty spaces in the fibers (Kiaei et al., 2014). Furthermore, the physiological growth of wood, including tree ages, diameter increase, and species, can influence lumen diameter (R & M, 2007); (Anupam et al., 2016). The present lumen diameter results suggest that the beating process of T. foetidissima and T. copelandii fibers could probably be favorable.

Cell Wall Thickness

Results of this study indicated that T. foetidissima has 6.524 µm and T. copelandii has 5.748 µm cell wall thickness. These average results were relatively thicker than those of the cell wall of some Terminalia spp. reported by (Singh et al., 2013) on T. arjuna (2.30 µm), T. myriocarpa (2.20 µm), T. bellerica (2.10 µm), and T. chebula (1.80 µm), while thinner than T. catappa (16.67 µm) (Aina et al. 2019). (F.P.R.D.I., 1996) also reported a slightly thinner cell wall of T. foetidissima with an average of 5.00 µm. Moreover, the cell wall of T. ivorensis (sapwood, 6.22 µm & heartwood, 6.46 µm) reported by (Antwi-Boasiako & Apreko-Pilly, 2016) seems to be comparable with the present result of T. foetidissima fibers. As compared to 3-, 5-, and 7-year-old F. moluccana (3.30, 3.20, 3.1 µm, respectively) (Alipon et al., 2021), A. scholaris (5.40 µm) and B. luzonica (4.73 µm) (Villareal et al., 2025), the cell walls of both T. foetidissima and T. copelandii were thicker, but thinner than F. callosa (7.70 µm), and F. variegata (9.57 µm) (Villareal et al., 2025). Basically, cell wall thickness increases toward maturity which is dependent on the accumulated metabolic products like holocellulose, lignin, and waxes (Ververis et al., 2004);(Shmulsky & Jones, 2019). Fibers with thick walls adversely affect the bursting strength, tensile strength, and folding endurance of paper (Kiaei et al., 2014);(Shmulsky & Jones, 2019). Based on the present result, T. foetidissima and T. copelandii fibers could be relatively rigid and may produce less dense paper but higher tearing strength, considering the impact of cell wall to the fiber flexibility and bulkiness of paper (Sharma et al., 2011).

Cell Wall Fraction

The result showed that T. copelandii recorded 33.688% cell wall fraction, while T. foetidissima recorded 31.842% exhibiting 5.634% difference. Although, no significant difference was observed with a P-value of 0.691. This present result was relatively lower compared to other hardwood species usually used for construction purposes like Peltophorum dubium (64.00%), Parapiptadenia rigida (57.80%), and Eucalyptus grandis × Eucalyptus urophylla (55.20%) (Eloy et al., 2024), while higher than those of underutilized native species in the Philippines (A. scholaris, 21.82%; B. luzonica, 26.40%; F. callosa, 29.15%; F. variegata, 36.72%) (Villareal et al., 2025), and underutilized fast-growing species in Indonesia (Macaranga bancana, 7.00% and M. pearsonii, 8.00%)(Wood properties related to pulp and paper quality in two Macaranga species naturally regenerated in secondary forests, 2016). A higher cell wall fraction slows a material's drying rate by reducing its capacity to hold moisture. This property also serves as a key indicator for industrial use, where a value below 40% suggests suitability for pulpwood and is linked to greater bending resistance through fiber flexibility (Kollmann & Côté, 1968); (Wood properties related to pulp and paper quality in two Macaranga species naturally regenerated in secondary forests, 2016); (Eloy et al., 2024). Additionally, the cell wall fraction is directly linked to wood’s basic density and inversely linked to its moisture content. Moreover, a higher cell wall fraction increases wood density and enhances its mechanical strength, making it more resistant (Sette Junior et al. 2012; (Lima et al., 2014); (Tanabe et al., 2016); (Eloy et al., 2024). The present results indicated that T. copelandii wood may have a slower drying rate, while T. foetidissima may exhibit a faster drying rate. These findings also suggest that both wood species could be suitable for pulpwood production.

Derived Values

Derived values of T. foetidissima and T. copelandii wood species, such as the Runkel ratio, Slenderness ratio, Flexibility ratio, Muhlsteph ratio, Rigidity coefficient, and Luce’s shape factor are presented in Table 2.

Table 2.Derived values of T. foetidissima and T. copelandii wood species

Property	Wood species		Significant levels of difference(P-value)
	T. foetidissima	T. copelandii
Runkel Ratio	0.555 (±0.107)	0.598 (±0.120)	0.664ns
Slenderness Ratio	43.525 (±4.079)	51.510 (±9.529)	0.253ns
Flexibility Ratio (%)	71.727 (±3.278)	67.379 (±4.729)	0.261ns
Muhlsteph Ratio (%)	45.751 (±4.998)	51.813 (±6.485)	0.269ns
Rigidity Coefficient	0.141 (±0.016)	0.163 (±0.024)	0.261ns
Luce’s Shape Factor	0.3666 (±0.063)	0.390 (±0.071)	0.691ns

Runkel Ratio

T. copelandii has a Runkel ratio of 0.598 and T. foetidissima has 0.555, showing 7.458% difference. However, the study found no significant difference (0.664 P-value), indicating a comparable Runkel ratio between the two species. The present result was relatively lower than the Runkel ratio of T. catappa (2.063) (Aina et al. 2019), F. variegata (0.74) (Villareal et al., 2025), but relatively higher to 3-, 5-, and 7-year-old F. moluccana (0.240, 0.220, and 0.260, respectively) (Alipon et al., 2021), A. scholaris (0.30), B. luzonica (0.38), and F. callosa (0.48) (Villareal et al., 2025). Moreover, the present Runkel result was comparable with the report of (F.P.R.D.I., 1996) on T. foetidissima with 0.59. According to Aina et al. (2019), fibers with Runkel ratio above 1.0 are expected to be thick-walled fibers forming a bulky paper sheet with lower bonded area and good mechanical strength qualities. Based on the Runkel ratio’s results, T. foetidissima and T. copelandii are relatively suitable as raw materials for pulp and papermaking. With this result, it could be recommended that T. foetidissima and T. copelandii plantations maybe established to support the production of pulp and paper in the country rather than planting exotic tree species.

Slenderness Ratio

Results of the study showed that T. copelandii recorded 51.510 slenderness ratio, while T. foetidissima recorded 43.525 showing 16.804% difference of results. However, the study found no significant difference (0.253 P-value), indicating a comparable slenderness ratio between the two species. The result of the study was relatively higher than those of 3-, 5-, and 7-year-old F. moluccana (34.33, 31.98, and 31.90, respectively) (Alipon et al., 2021), A. scholaris (37.13), B. luzonica (42.04), and F. callosa (35.87) (Villareal et al., 2025). As to the value obtained on T. catappa (45.567) by Aina et al. (2019), T. copelandii’s slenderness ratio was higher while T. foetidissima showed a little lower. Compared to F. variegata (60.48) (Villareal et al., 2025), the present result was lower. Furthermore, T. foetidissima and T. copelandii's slenderness results fell within the permissible range of 33 or above, as reported by (Kiaei et al., 2014), showing potential to pulp and papermaking purposes.

Flexibility Ratio

This study revealed that T. foetidissima's flexibility ratio was 71.727% and T. copelandii was 67.379%, showing 6.251% difference. Statistically, there was no significant difference between the results, indicating a comparable value for the flexibility ratio. The present results of T. foetidissima and T. copelandii were relatively higher than T. catappa (35.667%) (Aina et al. 2019), 3-, 5-, and 7-year-old F. moluccana (81.990%, 82.780%, and 82.840%, respectively) (Alipon et al., 2021), and F. variegata (65.35%) (Villareal et al., 2025), while lower than A. scholaris (77.74%), and B. luzonica (73.02%) (Villareal et al., 2025). (Bektas et al., 1999) flexibility classifications, both T. foetidissima and T. copelandii fibers fell under elastic fiber (ranging from 50 – 75%). This result indicates efficiency and appropriateness for paper manufacture. Technically, the flexibility ratio is one of the key indicators of a fiber's suitability for papermaking, as it measures its ability to collapse during beating or drying. This collapse creates a greater bonding area, and the degree of fiber bonding is largely dependent on the flexibility of the individual fibers (Zobel & Buijtenen, 1989). A higher flexibility ratio demonstrates higher tensile strength (Hartono et al., 2022). Furthermore, the flexibility ratio results of the present study suggest the suitability of T. foetidissima and T. copelandii fibers for pulp and papermaking.

Muhlsteph Ratio

Results of this study revealed that T. copelandii's Muhlsteph ratio (51.813%) showed 12.427% difference with the T. foetidissima’s Muhlsteph ratio (45.751%). However, the difference in results was not significant. Both T. foetidissima and T. copelandii Muhlsteph ratios fell in class II (values ranged from 30 – 60%) based on the classification used by (Hartono et al., 2022). This present result fell on the same Muhlsteph ratio class reported by (Villareal et al., 2025) on the underutilized native species grown in Maguindanao, Philippines, such as A. scholaris (39.08%), B. luzonica (46.28%), F. callosa (47.15%), and F. variegata (53.63%). The Muhlsteph ratio affects the pulp’s density, as well as the smoothness of paper and the plasticity between the fibers (Hartono et al., 2022). Based on the result, T. foetidissima and T. copelandii fibers could produce a paper with favorable smoothness and pliability which not easily torn off when folded.

Rigidity Coefficient

The study's findings revealed that T. copelandii has a rigidity coefficient of 0.163 and T. foetidissima has 0.141, showing 14.474% difference. However, the difference in the results between T. foetidissima and T. copelandii was not significant. Based on the classification used by (Hartono et al., 2022), T. foetidissima fiber falls under class II (ranges from 0.10 – 0.15), similar class with F. callosa (0.14), B. luzonica (0.14), and A. scholaris (0.11), while T. copelandii fiber falls under class III (greater than 0.15), similar class with F. variegata (0.17). Technically, a low rigidity coefficient indicates greater fiber flexibility, which enhances the paper's resistance to tearing under tensile stress (Hartono et al., 2022). Thus, the present result suggests that papers made from T. foetidissima and T. copelandii fibers have a substantial rigidity and stiffness properties.

Luce’s Shape Factor

The Luce’s shape factor of T. copelandii (0.390) showed 6.349% difference compared to the T. foetidissima (0.366). Although, no significant difference of the result was observed between species with a P-value of 0.691. Compared to the findings of (Villareal et al., 2025) (F. callosa, 0.33; B. luzonica, 0.30; and A. scholaris, 0.24), the present result was relatively higher, except for F. variegata with 0.43. Luce's shape factor serves as an index for the beating resistance of pulp, with lower values indicating less resistance to beating (Wood properties related to pulp and paper quality in two Macaranga species naturally regenerated in secondary forests, 2016). This factor is also an important fiber index directly related to the density of paper sheets. A Luce’s shape factor below 0.5 suggests an ideal value for pulp and paper production, indicating good strength (NagarajaGanesh et al., 2023). Therefore, the current findings on Luce’s shape factor further affirm the suitability of T. foetidissima and T. copelandii fibers for papermaking.

Overall findings suggest that T. foetidissima and T. copelandii species are well-suited not only for pulp and paper production but also for light construction applications and composite materials where extreme strength and durability are not essential. Both species can also be utilized for various products like wooden toys, shoes, pencil slats, matchsticks, toothpicks, ice cream spoons, popsicle sticks, boxes, shelves, moldings, sashes, doors, veneer, plywood, buoys, and floats. Any differences in the properties are likely influenced by several factors, including genetic composition, site conditions, soil elevation, silvicultural practices, and stand density (Shmulsky & Jones, 2019); (Alipon et al., 2021). To fully confirm their potential and suitability, however, it is vital to examine other wood properties, including physical, mechanical, and chemical characteristics.

CONCLUSION

This study offered valuable insights for the wood industry, academic institutions, and the scientific community about the fiber morphology and related characteristics of T. foetidissima and T. copelandii. Result revealed that T. foetidissima exhibited slightly larger and thicker fibers, and a little higher flexibility ratio, whereas T. copelandii displayed slightly longer fibers along with a little higher cell wall fraction, Runkel ratio, slenderness ratio, Muhlsteph ratio, rigidity coefficient, and Luce's shape factor. However, the differences in fiber morphology and derived values were not significant. These findings suggest that both T. foetidissima and T. copelandii fibers could be suitable for pulp and paper production, light construction applications, and composite materials. However, to fully assess their potential, additional research is needed on the physical, mechanical, and chemical properties, as well as factors such as diameter and age classes, height levels, and wood types. As interest in native tree species continues to rise, T. foetidissima and T. copelandii may have the potential to compete with industrial plantation species. Further research is essential to optimize key technological processes including seasoning, drying, veneering, and machining, while also developing effective propagation methods and establishing sustainable plantations for these species.

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