half of the plot, and trees 10 cm in DBH in four 1-ha subplots.
However, to increase the sample size of FCTs to which silvicultural
treatments were applied, all trees fulfilling the FCT criteria were
located in the entire 21.25-ha of the light silviculture (577 trees)
and intensive silviculture (761 trees) treatment plots (i.e. trees
were sample in 42.50 ha per treatment). FCTs in the normal
treatment were defined in the lab by selecting trees that had
excellent to good stem quality and perfect to tolerable crown form
(see Section 2.3. for more details; 763 trees selected). The FCTs in
the normal treatment were used for comparison as these trees
were growing in logged plots, but did not receive additional
silvicultural treatments. Silvicultural treatments applied to FCTs to
enhance growth rates were the following: cutting of lianas growing
on FCTs that had their stems below the projected crown area of the
tree (on average 5–6 lianas per tree were cut using a machete); and
girdling of competing trees with a chainsaw, followed by
application of the 2.4-D herbicide (at 20% solution) in the girdle
cuts (Table 2).
Plots were installed in 2002 (block 1) and 2003 (block 2) and
they were harvested by the concession workers 2–6 months after
plot installation. Depending on the treatment, harvesting intensity
ranged from 4 to 8 trees per ha, which resulted in 6.3–7.1% of the
area being included in logging gaps or skid trails (Mostacedo et al.,
2006). All plots were harvested using reduced-impact logging
techniques, which included pre-harvest inventory of merchantable
trees larger than the species-specific minimum cutting diameters
(40–50 cm DBH), lianas cut on merchantable trees 3–5 months
before logging, skid trial planning, retention of 20% of merchantable
commercial trees, and directional felling.