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Most
of the mapped lowland forest patches were confirmed
to be of high ecological value except for a
few sites (Table 7.1b) where ecological value
was downgraded to medium because of disturbance
due to pollution (eg rubbish dumping) or development
(eg slope stabilisation) and/or low structural
complexity and species abundance of the habitat.
The majority of the forest habitats are generally
well-preserved and subject to little or no
human disturbance.
Some
of the forest patches, such as Tai Lam Chung
(Site 13e), though small in size (about 0.4
ha), supported a closed, highly stratified
canopy and dense understorey vegetation. Large
patches (> 3 ha) of lowland forest were
observed within various Country Park areas
such as Tai Lam Chung (Sites 13a, b) and Shing
Mun (Sites 16b, c, g, h and i), Kam Shan (Sites
17c and e), Plover Cove (Site 19c), Pat Sin
Leng (Site 20a), Ma On Shan (Sites 21b and
c) and Sai Kung East (Sites 22c and e) or located
next to villages (eg Wong Chuk Yeung Village,
Site 18c). They were generally well-preserved
and structurally complex. Dense vegetation
growth and high species abundance were recorded
in these areas.
However,
a few of the small lowland forests appear to
have been disturbed by (regular) clearance
of their understorey vegetation. Such clearance
of vegetation serves to either provide sufficient
space for recreational activities (eg near
picnic areas) or landscape purposes (particularly
those established on slopes). A small number
of the surveyed patches were found to be subjected
to rubbish dumping.
Among
the Plantation sub-sites re-identified from
Lowland Forest, nine of them were considered
as of high ecological value (ie upgraded from
their indicative medium habitat value) because
of their apparent old age and the observed
structural complexity and species diversity
which has made them resemble a native secondary
forest. An "*" was assigned to one
of the re-identified plantation patches (Site
26d) as the area was found to be used by AFCD
as an experimental site for planting native
species on hill-sides.
Lowland
forest sites where ecological value has been
adjusted from their indicative ecological value
are presented in Table 7.1b (see Table G3 of
Annex G for details).
| Table
7.1b Rationale for Ecological Value Adjustment
of Lowland Forest Habitats based on Field
Surveys |
| Site
No. |
Site
Name |
Sub-site |
Ecological
Value After Field Assessment
|
Rationale
for Ecological Value Re-adjustment |
| 13 |
Tai Lam Chung |
f |
Medium |
Habitat had its ecological value downgraded
as the understorey had been cleared to
become a picnic area and supported comparatively
low species diversity.
|
| 17 |
Kam Shan |
b |
Medium |
Habitat disturbed by slope stabilisation work
and supported comparatively low species
diversity.
|
| 25 |
Pokfulam |
f |
Medium |
The lowland forest patch was found to be species
poor and regularly cleared for landscaping
purposes.
|
| |
|
g |
Medium |
Habitat disturbed by rubbish dumping.
|
| |
|
i |
Medium |
Habitat established on an engineered slope
and supported comparatively low species
diversity.
|
| |
|
j |
Medium |
The lowland forest patch supported comparatively
low species diversity and structural
complexity.
|
There
were two patches of re-classified Lowland Forest
which also had their ecological value downgraded
after field assessment (Table 7.1c). The two
patches were re-identified from Mixed Shrubland
(Site 36j Ma On Shan) and Shrubby Grassland
(Site 108h Victoria Peak).
| Table
7.1c Rationale for Ecological Value Adjustment
of Re-identified Lowland Forest Habitats
based on Field Surveys |
| Site
No. |
Site
Name |
Sub-site |
Initially
Mapped Habitat Type
|
Ecological
Value After Field Assessment
|
Rationale
for Ecological Value Re-adjustment |
| 36 |
Ma On Kong |
j |
Mixed Shrubland |
Medium |
Understorey
had been cleared and was sparsely vegetated.
Habitat supported lower species diversity
than other typical lowland forest in Hong
Kong. |
| 108 |
Victoria Peak |
h |
Shrubby Grassland |
Medium |
Habitat
disturbed by rubbish dumping and supported
comparatively low species diversity. |
|
|