ABSTRACT
This study had as objective to estimate the above ground biomass production and the percentage distribution of its components and nutritious amount in an 18-year-old-Hovenia dulcis stand planted in Foundation of Agricultural Research (FEPAGRO), Santa Maria, RS. Through the sampling of four randomized plots, trees were distributed in four diametric classes, with size of 5,75 cm, in which the upper and the lower limit trees were cut down, as well at the medium limit trees. Considering the model lny = b0+b1.ln DAP+b2.ln h, and using 12 trees, the biomass from different components of the trees was estimated. The estimated biomass was 181.6 Mg ha-1, being distributed in the following order: wood 68.6%, branches 15.5%, bark 11.2% and leaf 4.7%. The leaves showed higher contents of N, Ca and Mg (23.0; 29.7 e 5.4 g kg-1, respectively) and the wood showed the lower contents (2,0; 1,3 e 0,6 g kg-1, respectively). The bark (0,5 e 3,6 g kg-1) got higher indexes of P and K, and the leaves (0,18 e 0,70 g kg-1, respectively) the lower indexes. The amount of N, P, K and Mg was higher in the wood due to its huge biomass. The bark showed a higher amount of Ca, 500.8 kg ha-1. Based on this, the wood harvest should be prioritized, considering the other fractions being in the system and cycling its nutrients for later rotations.
Keywords:
nutrient cycling; forestation; sustainability