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Underplanting: planting young trees under the canopy of an existing
stand. |
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Understorey:
any plants growing under the canopy formed by other
plants, particularly herbaceous and shrub vegetation under a tree canopy. |
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Uneven-aged silvicultural system:
a silvicultural system designed to
create or maintain and regenerate an uneven-aged stand structure. Single-tree
and group selection are uneven-aged silvicultural systems. |
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Uneven-aged stand:
a stand of trees containing
three or more age classes. In a balanced uneven-aged stand, each age class is
represented by approximately equal areas, providing a balanced distribution of
diameter classes. |
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Unmanaged forest land:
forest land that is not subject to management
under a forest management plan. |
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Unmerchantable:
of a tree or stand that has not attained sufficient
size, quality and/or volume to make it suitable for harvesting. |
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Unrecovered timber: timber as described in the Provincial Logging
Residue and Waste Management Procedures Manual. |
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Unrecovered volume: timber that is within the cutting specifications
of the minimum utilization standards of the cutting authority and not removed
from the area. |
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Unsalvaged losses: the volume of timber destroyed by natural causes
such as fire, insect, disease or blowdown and not harvested, including the
timber actually killed plus any residual volume rendered non-merchantable. |
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Unstable or potentially unstable terrain:
an area where there is a
moderate to high likelihood of landslides. |
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Uplands: terrain not affected by water table or surface water or else
affected only for short periods so that riparian (hydrophilic) vegetation or
aquatic processes do not persist. |
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Urban forestry:
the cultivation and management of trees and forests
for their present and potential contributions to the physiological, sociological
and economic well-being of urban society. |
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Utilization (of forage and browse): the level of forage and browse use
on a site. For herbaceous species, it is measured as a percentage of the current
year's growth removed; for browse species, it is measured as a percentage of
stem ends removed. |
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Utilization standards:
the dimensions (stump height, top diameter,
base diameter, and length) and quality of trees that must be cut and removed
from Crown land during harvesting operations. |