Describing the Structure and Relationship of Height and Diameter in an Old Unmanaged Eucalyptus spp. Plantation

Abstract

Abstract The aim of this study was to model the height and diameter distributions and the height-diameter relationship in an old unmanaged Eucalyptus stand in southeastern Brazil. The diameter at 1.30 m above soil (DBH) and total height (H) of all 469 trees in the stand were measured. For the DBH-H modeling, besides testing various traditional linear and nonlinear models, the inclusion of diameter class as random effect was also testes. For the DBH and H distributions modeling, seven probability density function were tested. The DBH-H relationship was best represented by the Henriksen’s linear model. Including diameter classes as a random effect did not improve estimates. The three parameters Weibull distribution was the best model to describe the diameter and height in old and unmanaged planting of Eucalyptus. The DBH distribution showed the highest frequency of individuals in lower diametrical classes, influenced by competition, while H had distribution similar to normal.

Keywords

• Forest inventory
• Forest structure
• Mixed effect models
• Probability density function
• Tree height prediction