Mixed settlements of eucalyptus and acacia in transition area between Brazilian Savana (Cerrado) and Amazon Forest biomes.

The adoption of mixed planting with eucalyptus and legume tree espcie - able to fix nitrogen, is a sustainable alternative to provide nitrogen to the eucalyptus. Our objective was to evaluate if the mixed planting of eucalyptus and acacia yields basal area equivalent to homogeneous eucalyptus planting. The treatments evaluated were: Eucalyptus (E, clone I144 - E. urophylla x E. grandis) with and without nitrogen fertilization (0A: 100E + N e 0A: 100E-N), acacia (A, Acacia mangium) (100A: 0E), acacia and eucalypt ratio 1:2 (33A: 67E) and 1:1 (50A: 50E). Randomized blocks design (RBD) was used, with four replicates and plot with 1,296 m² (12 x 12 trees) and 576 m² of useful area (double surround, with spacing 3 x 3 m). The trees were measured at three years of age by circumference at brest height (CBH) and basal area (BA, m² ha-1). BA was different among treatments (p 0.35, in both acacia represented 60% and 84% of the BA for 1:2 and 1:1 ratio between eucalyptus and acacia. The interspecific competition was positive for acacia and negative for eucalyptus.Abstracts of the XXV IUFRO World Congres