Radial Variation of Fiber Length Increment in Acacia Mangium

Abstract

The radial variation of fiber length increment (due to intrusive growth) and its relation with internal and external (climatic) factors were investigated for Acacia mangium trees collected in Indonesia and Malaysia. Wood fiber length and fiber length increment were approximated with respect to the distance from the pith (x) by a logarithmic function and vessel element length by a linear function. The results were y = 0.14 . ln(x) + 0.48, y = 0.0005 . x + 0.20, and y = 0.13 . ln(x) + 0.31, respectively. The radial variation of fiber length was related to the growth rate rather than the age of the cambium. The results of the cross-correlation function between wood fiber length increment and climatic factors showed that fiber lengths responded to changes in precipitation with a time lag of between zero to four months.