Crown morphometry of Eucalyptus grandis Hill ex Maiden x E. urophylla S. T. Blake stands in different planting spacing

Abstract

The canopy morphometry and its relationships with space and time subsidize decision-making on plant density and silvicultural interventions in forest stands. The aim of this work was to evaluate the effect of planting density and age on the canopy morphometry of Eucalyptus grandis x E. urophylla. The experiment was established in a randomized three blocks design, split plot scheme in time. The main treatments consisted of four planting spacing (T1: 3,0 × 0,5 m; T2: 3,0 × 1,0 m; T3: 3,0 × 1,5 m e T4: 3,0 × 2,0 m).at four ages (24, 37, 48 e 59 meses). The following morphometric indexes were calculated: Canopy Proportion (CP), Canopy Formal (CF), Slenderness Rate (SR), Range Index (RI) and Salience Index (SI). RI was the only morphometric attribute that interacted with spacing and age. CP, RI and SI tended to decrease over time. CF and SR remained statistically stable between 24 and 59 months of age. The trees of the spacing 3.0 × 2.0 m expressed lower SR, SI and, at the age of 59 months, RI, implying less intraspecific competition and more resistance to the weather. Planting spacing and age influenced the morphometry of the canopy of eucalyptus trees.