We will now move on to present the methodology, data and calculations we have used to foresee the outcome, in terms of wood volume, that each full-grown individual will produce.
Commercial height (CH): We expect the trees to be roughly 17.00 meters in height and we consider that 12.00 meters out of this total are commercial. The commercial height was defined as being up to 20 centimeters of diameter (which corresponds to the minimum diameter necessary for the entry of trunks into the machinery in most mills.).
Trunk quality (FA): The stem shape varies. According to the “Manual para Produção de Madeira na Amazônia” (“Production of wood in the Amazon region” manual): “the trunks vary in their commercial qualities. Straight trunks, cylindrical and without hollows are classified as “good” for wood uses. Straight trunks but with small hollows along the whole log, or crooked trunks without hollows are classified as “regular”. Crooked trunks with hollows are of “inferior quality”
In the table bellow, we have the relation between the trunk quality and the good use proportion of its volume. The factor in this table (FA) is multiplied by the total volume. We will then have the “usable” commercial volume. For foresting purposes, we have adopted the FA factor as 0.90 because only the best trees will remain.
The trees diameters are usually measured with slide caliper at chest height at 1.30 meters from the ground. This measure is called DCH (diameter at chest height/DCH). We expect a DCH of 38 centimeters at cut time. With a bark 1.5 centimeter thick, we have 35 centimeters free.
Besides the DCH, if we measure the diameter at base heights, 25%, 50%, 75% and 100% of the commercial height, we can observe the log cone of a tree to be cut. Taking into consideration this volume reduction in order to calculate the volume, we adopted a cone factor of 0.80.
Commercial volume determination (Comv):
Each full-grown “Guanandi” tree will produce an average of 0.8313 m3 of wood. In determining the volume of each tree, we must apply the diameter at chest height (DCH), commercial height and trunk quality factors. We applied the following formula:
Comv (m3) = (π x DCH2 x CH x FA x CO)/4, where:
Comv = Commercial wood in cubic meters.
DCH = Diameter at chest height (0.35 m).
CH = Commercial height (12.00 m).
GUF = Good use factor (0.90).
CF = Cone factor (0.80).
Based on our observations of a lot of variables made from visiting individuals, we have adopted an initial spacing of 3 by 3 meters for seedlings planting. At the end, we expect to have 152 trees per hectare (Qha) after clearing the space surrounding the remaining trees.