Variation of Wood Density and Anatomical Characters From Altitude Differences: Case Study of Selected Fabaceae Trees in West Sumatra Secondary Forest, Indonesia

There are three tree species of Fabaceae used for furniture in the secondary forest of coastal to mountain areas in West Sumatra, Indonesia. Their wood samples were collected from secondary forests of altitude ranges. Wood density was calculated as dry weight divided by green volume. The anatomical characters are measured on transverse, radial and tangential sections. The results showed that Senna sumatrana showed moderately heavy of wood density at ≤600 m asl, Gliricidia sepium at >600 m asl, and Pterocarpus indicus at altitude 300 to 900 m asl. There are negative correlation between wood density and altitude on S. sumatrana (r = -0.967), negative correlation on G. sepium (r = +0.918) and P. indicus (r = +0.898). A ray height shows the positive correlation with the altitude for S. sumatrana (r = +0.957), G. sepium (r = +0.898), and P. indicus (r = +0.898), while other anatomical characters may exhibit positive or negative correlation. Based on analysis of multiple correlations that the wood density variables of S. sumatrana, G. sepium and P. indicus is determined by anatomical character variables with r -0.998, +0.987 and +0.993 respectively. This finding suggests that the relationship between wood density and anatomical characters of these three species can be described successfully using multiple regression equation models. The relative contribution of determinant for wood density value in S. sumatrana was determined by fiber, vessel and rays components, but G. sepium was determined by fiber and rays components, and P. indicus was determined by fiber only.     Keywords: wood density, anatomical characters, Fabaceae trees, altitud