Mathematical model for predicting the physical properties in the wood of Eucalyptus nitens for different heights and ages of tree

Abstract

Eucalyptus nitens has a great potential for its use in higher value-added products, mainly due to its growth rate and adaptability to different soils and climates. However, its use is still limited, due to lack of knowledge of its physical properties throughout the log. In this sense, the objective of the research was to model the physical properties at different heights and age of the tree. To do so, 40 trees of 13 years, 12 of 15 years and 5 of 20 years were selected, evaluating their physical properties from the base (0.3 m) to the Usable Free Diameter of 8 cm. The basic density and moisture content were determined by standard NCh176/2 Of. 86 and NCh176/1 Of. 86, respectively. The results showed a basic density at 13 years of 474 kg/m³, with a moisture content of 116%, at 15 years it was 496 kg/m³ and 108% and at 20 years it was 521 kg/m³ and 104% respectively. There was an increase of 4.6% and 9.7% in the basic density at 15 and 20 years compared to 13 years. The model detected an inverse relationship between the basic density and moisture content, both presenting a high correlation with the height and age of tree. Finally, the model predicted with high level of precision the physical properties in Eucalyptus nitens trees. So, it can be used as a tool to support decision-making when defining the use of logs according to the type of product to obtain.

Keywords:
Basic density; Moisture content; Statistical analysis