Components of Tree Biomass in an Integrated Crop-Livestock-Forest System

Aims: This study performed the adjustment of volumetric models, and determined the biomass of Eucalyptus grandis x Eucalyptus urophylla hybrid cultivated in a crop-livestock-forest integration system (CLF).

Study Design: The experimental area consists of a crop-livestock-forest integration system where trees are hybrids clones of seven year old Eucalyptus grandis x Eucalyptus urophylla.

Place and Duration of Study: This work was carried out at Fazenda Santa Brígida, Ipameri, Goiás (Brazil).

Methodology: A forest inventory of the area was carried out in October 2015 when the tree component was fully developed. Diameter at breast height (DBH) (at 1.30 m) and total height (H) of trees were measured in the field and categorized according to 4 classes. Afterwards, 12 trees were felled, which were cubed and compartmentalized to determine the volume and biomass of their components. The volumetric models developed by Schumacher & Hall and Ogaya were applied to obtain determination coefficients.

Results: The average DBH was 18.28 cm and the average H was 23.47 m. The highest volumes of wood were observed in the diametric classes that presented the largest number of individuals, however in the class of higher DBH an average individual volume of 0.36 m3 of wood was observed. The total biomass of Eucalyptus was 56.64 Mg ha-1, being 83.70% wood, 6.52% in branches, 6.37% in bark and 3.40% in leaves.

Conclusion: The volumetric models developed by Schumacher and Hall as well as Ogaya were found to be applicable for estimating the volume of wood in CLF systems, where both showed a determination coefficient of 0.866.