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Still, tropical forestry is generally synonymous to harvesting,
often in primary forest with a high volume of large trees.
If harvesting were the only management activity, tree mining
would be a better term describing the activity than forestry.
On lands designated for the permanent production of timber
(or non-timber products), forest stands need to be silviculturally
tended in order to safeguard a continuous supply of timber.
Many silvicultural systems have been proposed to manipulate
the post-harvest forest stand with a view to increase the
contribution of commercial species in the stand and improve
their growth. Most of the more favoured silvicultural systems
are polycyclic (i.e. timbers are not harvested at once but
selectively during several cycles) and based on natural regeneration.
Common elements of such systems include application of RIL,
selective liberation of future crop trees, thinning of undesired
trees. If natural regeneration is scarce line planting of
seedlings is sometimes prescribed. Silvicultural techniques
varied considerably from place to place, depending on the
variability, diversity and complexity of the forest ecosystem
and changing attitudes to natural and artificial regeneration.
Monocyclic systems, in which the entire tree crop is harvested
at once, are nowadays considered less acceptable in forests
that need to fulfil multiple purposes.
Only in Asia (Malaysia, Indonesia), silvicultural systems
have been applied routinely over large areas, but in many
cases the silvicultural strategy has changed before the second
logging cycle. Today, few if any of these systems are applied
on a practical scale. As a rule, there is little doubt about
the technical feasibility of tropical silviculture, but many
other factors militate against their successful application.
An important factor is that silvicultural systems have emphasised
the timber-producing aspects of sustainable forest management,
generally disregarding the social and environmental components
of the concept. The absence of clear land development policies
in many countries, the unfavourable socio-economic conditions
facing growing human populations, and political circumstances
have all contributed to their failure.
TBI sources
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