ANATOMICAL RADIAL VARIATION AND DENSITY IN WOOD OF RUBBER TREE [Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.] CLONES

Abstract

The anatomical structure and physical properties of wood change signifcantly among trees of the same species and even among different parts of the same tree. However, studies that characterize radial variation of anatomical characteristics and wood density among clones are scarce, specifcally for the rubber tree [Hevea brasiliensis (Will. ex Adr. De Juss.) Muell]. Thus, the objective of the research was evaluating the anatomical radial variation and density in wood of Hevea brasiliensis clones. For this study, 30 trees, three of each progeny from 10 clones were used. For most clones, we noticed an increase in fber length and vessel diameter towards the bark. For vessel frequency, ray height, width and frequency, we observed a decrease towards the bark. Fiber wall thickness was the most distinctive anatomical characteristic, compared to the others, presenting a trend of thicker walls in the middle position, consequently infuencing basic density clones.

VARIATION OF THE ANATOMIC CHARACTERISTICS OF Anthocleista grandiflora WOOD AS A FUNCTION OF TREE AGE AND TRUNK POSITION

“…The research analysis showed that the greatest fiber length is in the sapwood region, the middle section of the 47-year-old -the value was 2.93 ± 0.13 mm. Comparatively, A. grandiflora has a higher average fiber length than other timbers such as Sorbus terminalis (1.57 mm), reported by Bahmani et al (2020); Terminalia ivorensis (1.20 mm) and Triplochiton scleroxylon (1.30 mm), reported by Awaku (1994); and Hevea brasiliensis (1.18 mm), reported by Amorim et al (2021). Thus, according to IAWA (1989), A. grandiflora is classified as medium-length fiber wood.…”