An Investment Plan for Ngoc Linh Nature Reserve - Birdlife ...

Section 2 - Site Features
This rich, undisturbed forest type is distributed not only on the slopes of Mount Ngoc Linh and Lo Xo
Pass but is found throughout the Cong Troi area and the south of Mang Xang commune. Ngoc Linh
Ginseng is unevenly distributed in this forest type at altitudes over 1,700 m.
At an elevation of 1,700 m, medium to high montane broadleaf evergreen forest is stratified into four
layers:
(a) Emergent Layer. The emergent layer in many areas is uniform and almost continuous.
This layer is at a height of 15 to 17 m and consists mostly of broadleaf trees such as Betula
alnoides, Castanopsis indica and Dacrycarpus imbricatus. This is only 2 to 4 m higher than
the high montane broadleaf evergreen forest at higher elevations;
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(b) Middle Layer. The middle layer is not referred to as a closed canopy because it is broken by
large areas or stands of emergent trees. Continuous areas of the middle layer are directly
underneath, and often appear continuous with, the emergent layer. The canopy layer differs
from the emergent layer primarily in that it includes many species in the Rubiaceae and
Euphorbiaceae;
(c) Lower Layer. The shadetolerant
lower layer is
dominated by Calamus sp.
and members of the
Polypodiaceae; and
(d) Ground Layer. The ground
layer is a mixed shrub and
herbaceous vegetation layer
of both monocotyledons
and dicotyledons. This
layer includes saplings of
the upper three vegetation
layers which, particularly
when growing with lianas,
make small patches of this
layer appear continuous
with the lower forest layer.
Forestry data on percentage density and basal area of each
major tree species, used to calculate mean timber values,
is also indicative of the dominant tree species in this forest
type. These species are listed in descending order of
density, and give a good view of the composition of this
forest type (Table 7). The density of saplings in this forest
type (Table 8) shows a different composition to the
mature forest trees, suggesting that this highly developed
forest type has complex stratification dynamics.
Low Montane Broadleaf Evergreen Forest
This forest type is distributed at altitudes less than 1,000
m, on red and yellow feralite soils with a bedrock of granite,
arenaceous and other altered rocks. Although extensive
Table 7: Composition of Mature Trees in Medium to
High Montane Broadleaf Evergreen Forest
Taxon Density (%) Basal Area (%)
1. Betula alnoides 13 20
2. Eurya japonica 12 10
3. Litsea verticillata 7 12
4. Quercus spp. 7 11
5. Castanopsis indica 6 15
6. Symplocos cochinchinensis 6 5
7. Engelhardtia spp. 6 4
8. Cinnamomum balansae 6 1
9. Quercus chevalieri 6 1
10. Nephelium lappaceum 4 1
11. Dacrycarpus imbricatus 4 5
12. Schefflera octophylla 4 2
13. Elaeocarpus spp. 4 1
14. Pterospermum lanceaefolium 3 1
15. Rhodoleia championii 8 1
16. Other species 4 10
Table 8: Composition of Saplings in
Medium to High Montane Broadleaf
Evergreen Forest
Taxon Density (%)
1. Quercus spp. 20
2. Eugenia spp. 16
3. Lauraceae 16
4. Gironniera subaequalis 9
5. Albizia lucidior 7
6. Mischocarpus sundaicus 7
7. Elaeocarpus spp. 5
8. Litsea monopetala 5
9. Randia acuminatissima 5
10. Other species 7