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Review of Urban King Trees in the Past Ten Years |
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“King of Hong Kong”
Urban Trees Competition was hosted by Provisional Urban Council, and
co-hosted by The Conservancy Association and RTHK. The elected nine
Urban King Trees are still listed in the Register of Old and
Valuable Trees.
One third of the tree trunks of the Chinese Banyan, known as ‘King
of Hong Kong Urban Tree’, collapsed in Kowloon Park on 13 August
2007. The collapse alerted the public on the inadequacy of tree conservation
works, especially those of old and
valuable tree in Hong Kong. In September, the
Conservancy Association surveyed the remaining
eight Urban King Trees. We discovered that most of
them received inappropriate care, with three of them having potential
risks of collapse.
Trees are important assets
to the society and conservation work should not be ignored. While the
Administration has spent enormous amount public money on tree planting and
urban greening, sufficient resource should also be put on tree
conservation. |
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Chinese Banyan (Ficus
microcarpa)
LCSD E/16 top |
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| Health condition |
Structure |
Environment |
Comparison with the condition in 1997 |
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Fair, slow growth, vigorous
production of watersprouts on the tree trunk and braches,
5-10% dieback |
There are many wounds due to
poor pruning; sign of decay on some of the wounds as well as
tree roots which located near roadside; aerial roots were
removed; many branches were lion tailed |
The tree crown is near to
buildings nearby, tree roots were covered by road, lack of
space for the development of tree roots |
The tree crown became smaller,
it is good due to the reduction of the weight of the crown,
however, no aerial roots can reach the ground and lignified,
this can seriously affect the health and the support of the
tree |
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West Indies Mahogany (Swietenia mahagoni)
LCSD WCH/23
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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good, 5-10% dieback
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wounds due to improper pruning
at the lower part of the tree trunk, signs of decay, fungi
on several branch surfaces may indicate internal decay, but
not serious |
30% of the roots grow under the
paved trail in the cemetery, may affect long term growth
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tree crown denser, good health
condition, no serious structural problem. |
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| Burmese Rosewood (Pterocarpus
indicus) LCSD CW/86
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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good, 5% dieback, but yellow
leaves and dark green veins may indicate malnourishment
(i.e. deficiency of iron) |
wounds due to improper pruning
mainly at the lower part of the tree trunk, some of the
larger wounds covered with concrete, as a result cannot
determine whether there are signs of decay, water sprouts |
70% of the roots covered,
compacted soil |
tree crown denser, overall
health condition good, but concrete covering the trunk show
sign of loosening and poses potential hazard. |
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| Rain Tree (Albizia saman)
LCSD S/9
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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good, growth normal, but water
sprouts at various locations, 10% dieback |
Formation of wound wood at
several locations, some of the wounds are quite large, two
of which show signs of decay, many pruning wounds also show
signs of decay, trunk leans towards Wong Chuk Hang Road,
roots at opposite side grow under concrete, exposing parts
show signs of decay |
Probability of the tree will
collapse towards Wong Chuk Hang Road due to leaning and
decaying root, insufficient space for root growth, 80% of
the roots covered |
The leaning angle more acute,
tree crown at the side of a private nursery thinner than at
the side of Wong Chuk Hang Road, may indicate root problems,
crown should be thinned to reduce weight. |
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Chinese Banyan (Ficus microcarpa)
LCSD YTM/97
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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Very poor, only 20% tree crown
left, aerial roots few, but some reach ground, lots of
die-back, indicate serious root problems |
One-third of trunk collapse,
slight leaning, pruning wounds at many branches and aerial
roots, show signs of decay |
Large area of roots once
covered with concrete/tiles, roots truncated due to
engineering works; seriously damaging roots and affecting
absorption of water and minerals. |
Overall condition very poor,
Probability of dying |
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Silk-tree (Albizia julibrissin)
LCSD SSP/16
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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Good, dense tree crown, but
water sprouts at main trunk and branches |
Several pruning wounds, some
show signs of decay, formation of wound wood at several
locations, several branches lion-tailed |
60% roots covered, seriously
affect absorption of water and minerals, part of roots under
a fencing wall, impact unknown |
Leaning angle more acute, local
residents pointed out that two large branches collapsed and
caused damage to the buildings nearby, tree crown should be
thinned and supported with CORBA bracing |
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| Chinese
Banyan (Ficus microcarpa)
LCSD KC/1
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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Good, slow growth, 5-10%
die-back, few aerial roots |
Several pruning wounds, show
signs of decay, many pruned aerial roots, several branches
lion-tailed |
10-20% of roots covered by
tiles and road and mainly on one side, may lead to unbalance
growth, soil compacted and hard |
Main trunk widened from 0.6m to
1.8m because of aerial roots reaching ground, but no aerial
roots far from the main trunk can reach ground, will affect
health and support in the long run, main trunk begins to
age, allowing aerial roots to reach round very important for
the caring of the tree, extension of tree crown hinders
growth of other trees |
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Silk-tree (Albizia julibrissin)
HD KT/1
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
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Good, 5% die back |
Several pruning wounds, some
with formation of wound woods, but some also show signs of
decay, two large cuts (with diameter about 40cm), may lead
to internal decay, long term monitoring needed |
Ample space for growth and off
limit, protection enough. Installation of flood light,
effect of the heat to the tree should be closely monitored,
the installation process may injure the roots |
Tree crown thinner, but
conducive to reducing the weight of the crown |
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Chinese Banyan (Ficus microcarpa)
LCSD WTS/8
top |
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| Health
condition |
Structure |
Environment |
Comparison with
the condition in 1997 |
| Good, but
several locations with water sprouts, lush growth of aerial
roots |
Several pruning
wounds with water sprouts, branches facing the park square
may be topped because of the construction works |
Located at the
park entrance, 90% of the roots covered with tiles, aerial
roots pruned and cannot reach the ground |
Not many
changes, the location of the entrance should be moved and
provide more space for the root system and aerial roots,
reduce human disturbance to the tree |
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