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Harvesting
options and techniques
If timber is the only desired product from
a farm forest, and the aim is to maximise profit, clearfelling
large areas will reduce harvesting costs and probably maximise
the return. However, where trees also provide salinity control,
wildlife, shelter or other values, harvesting small volumes
over a longer period might be preferred.
The cost effectiveness of different harvesting methods may also
depend on the size of logs and how accessible they are. For
example, large, pruned and well-spaced trees are easier to harvest
than small, branchy trees growing in a dense plantation. This
allows a trained operator using a chainsaw, farm tractor, loader
and log trailer to be cost competitive with an operator using
specialised mechanical log harvesting machines. In some circumstances,
the costs associated with using small scale logging equipment
can be higher than the trees value.
The harvesting method chosen will also depend on regeneration
requirements. Light demanding species, such as eucalypts, might
need to be a full tree height away from any mature trees to
grow well. This means that a gap of 3050 metres might
be needed. More shade-tolerant speciesfor example, rainforest
trees or softwoodsmight grow well in the gap left after
one tree is harvested. In some cases the second generation can
be grown amongst well-spaced older trees prior to harvest.
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