o_19ko2dt161ng2j4e1tgnoqv1s45a.pdf

CONSERVATION STRATEGIES OF SHOREA LUMUTENSIS (DIPTEROCARPACEAE) IN PENINSULAR MALAYSIA
A total of 416 individuals >1 cm dbh were recorded within the 8-ha plot in Sungai Pinang. The
population density of S. lumutensis >30 cm dbh within the plot was 4.4 trees ha -1 . The prominent
associated species within the habitat are two palm species, i.e., Eugeissona tristis and Calamus
castaneus. The study of the relationship between microtopography and spatial distribution
showed that the species distribution was strongly related to topography; prominent on ridges
and upper slopes, and totally absent in the lower slopes and valleys. This was further supported
by spatial distribution analyses, in which significant spatial aggregation was detected at four
size classes (Fig. 2) and the level of aggregation was highest in SEE and SAP, followed by
POL, and then BIG.
Diameter distribution was skewed, with many more small than large individuals being present.
The distribution was significantly fitted to inverse J-shaped curves (y = ae -bx ; a = 154.6; b =
0.6; r² = 0.98, P < 0.01), indicating abundant regeneration. The medium-sized trees (11–20
cm) constituted 1.7% of the total 416 individuals found within the plot, compared with 8.2% in
the largest-sized trees (>31 cm) and 82.2% in the smallest-sized trees (1–5 cm). Short-term
population dynamics derived from the initial census in September 2001 and a repeat census in
August 2004 showed that a total of 75 trees died over the 3-year study period. Mortality was
detected only at the two lowest-sized classes (1–5 cm and 6–10 cm), 22% and 8% respectively
(Table 1). Growth was slow in most of the trees enumerated, at mean rates around
0.3 mm yr -1 (lowest-sized class) to 2.4 mm yr -1 (highest-sized class) and the mean growth rate
increased with increasing size class.
15
BIG
30
25
POL
10
20
Ripley’s K
5
0
Ripley’s K
15
10
5
0
-5
-5
-10
-10
0 1 2 3 4 5
0 1 2 3 4 5
clas s
Distance class
class
Distance class
70
60
SAP
90
80
SEE
70
50
60
Ripley’s K
40
30
20
10
0
-10
0 1 2 3 4 5
Distance clas class s
Ripley’s K
50
40
30
20
10
0
-10
-20
0 1 2 3 4 5
Distance class class
Fig. 2. Spatial distribution analysis using Ripley’s K-function on four diameter classes of
S. lumutensis within an 8-ha (400 200 m) plot: large trees (BIG >25 cm), pole trees (POL
4–25 cm), saplings (SAP 2.0–2.5 cm) and seedlings (SEE 1.0–1.1 cm). Distance classes were
defined at five intervals, each of 20 m, from 0–20 m (class 1) to 80–100 (class 5). Dotted lines
represent 95% confidence limits.
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