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Silviculture
is the art and science of
growing trees and managing
forest vegetation to meet the
resource objectives of the
landowner. Starting with
the replacement of the existing
forest, timber and non-timber
objectives are assessed and
accommodated through the choice
of silviculture system,
reforestation, brushing and
weeding, stocking surveys,
juvenile spacing, pruning,
commercial thinning, and
fertilization.
Previously,
progressive clearcutting was the
predominant silviculture system
applied in the district.
Currently, there is a wide range
of silviculture systems applied.
The retention silviculture
system is used most often, but
also utilized are the seed tree,
shelterwood, patch cut, clearcut
with reserves, and clearcut.
Commercial thinning is utilized
on the older second growth
stands found on the East Coast
of the district.
Commercial thinning salvages
trees that are dead or dying
from inter tree competition,
allowing the remaining trees to
stay healthy and grow unimpeded
until the next planned harvest
entry.
To meet their
basic silviculture obligations
planting is the preferred method
of most licensees. On
average there are 4 million
seedlings planted annually in
the South Island Forest
District. There are nine
different coniferous species and
2 deciduous species used in
reforestation. The choice
of species is based on the
management objectives and the
ecology of the area harvested.
Principle species planted are
douglas-fir on the east coast,
and western hemlock, western red
cedar and amabalis fir on the
west coast. Other species
planted are grand fir, western
white pine, yellow cedar,
lodgepole pine, mountain
hemlock, red alder, and hybrid
poplar. Natural
regeneration, while cheaper, is
less reliable and usually
results in longer regeneration
delays with irregular
distribution, and lower yields.
Natural regeneration augments
planted seedlings and adds to
the overall stocking and
biodiversity of all sites.
Over 85% of
seedlings planted in the
district survive and grow.
These seedlings may be protected
from deer or elk browse, and are
monitored by regeneration
surveys until they meet
specified free growing
standards. Licensees will
conduct brushing and weeding
treatments until the free
growing standards are met.
Incremental
silviculture treatments,
juvenile spacing, pruning and
fertilization, are evaluated for
treatment under the Forest
Investment Account (FIA) once
the trees are free growing.
The FIA account is administered
and audited by Price Waterhouse
Coopers (PWC) under principles
established by government.
Licensees assess the stands and
apply directly to PWC for
funding. Treatments are
monitored for compliance with
legislation, and environmental
standards by district staff.
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