Silvicultural performance of eucalyptus in two planting models in a silvopastoral system

Abstract

The objective of this study was to evaluate the silvicultural performance of eucalyptus-urograndis hybrid (Eucalyptus urophylla x E. grandis) in two plantation models in a silvopastoral system, installed Paranaíta – Mato Grosso state (Brazil). The models of silvipastoral systems evaluated were: model 1 = simple lines of eucalyptus-urograndis, in spacing 6 x 35 m; and model 2 = simple lines of eucalyptus-urograndis associated with african-mahogany (Kaya ivorensis), in a 3:1 ratio, in a 4 x 35 cm spacing. In each of the planting arrangements, three plots of 20 trees randomly distributed were sampled. The dendrometric variables evaluated were: trunk diameter at 1.3 m above ground height (DBH), total height (Ht), crown area (Ac) and bark thickness. The proportion of damage to the bark caused by cattle and the height of damage to the trunk of the trees was also evaluated. The collected data were statistically analyzed by the non-parametric Kruskal-Wallis test, followed by the Dunn test (p < 0,05). The eucalyptus-urograndis in the silvopastoral system in planting model 1 had the best silvicultural performance, due to the highest increments of Ht and DBH, in addition to the smaller amount of trees damaged by cattle.