86
difficulty of extracting roots from the muddy soils. Different allometric equations
for aboveground biomass are used for different mangrove species (Tam et al. 1995;
Ong et al. 2004; Comley and McGuinness 2005) and sometimes at different forest
sites (Clough et al. 1997), although Ong et al. (2004) applied similar equations to
two different Rhizophora apiculata forest sites. Komiyama et al. (2005) developed
the following universal allometric equation for mangrove trees with a trunk diameter of <49 cm:
W above
DBH
= 0 251
2 46
.
.
r
(3.1)
where W above (kg dry weight) is the aboveground biomass, ρ is wood density (g cm
−3
),
and DBH is the trunk diameter at breast height (cm). They based this equation on
the pipe model, which relates biomass to the cross-sectional area of stems and
branches (Shinozaki et al. 1964), and the static plant form model, an extension of
the pipe model (Oohata and Shinozaki 1979). Wood density of mangroves varies,
depending on the species, from 0.486 to 0.980 g cm
−3
(Putz and Chan 1986; Clough
and Scott 1989). A comparative analysis of reported allometric equations (using
mainly data obtained in Southeast Asia) showed that estimates of aboveground biomass obtained by using the universal equation are the same, within a 10% relative
error, as estimates obtained by using site-specific equations (Komiyama et al. 2008).
Table 3.5 Mangrove biomass estimated as W above or below = A DBH
B
, where W is biomass (kg dry
weight) and DBH is diameter at breast height
Species
DBH (cm)
n
A
B
r
2
References
Aboveground
Avicennia germinans
<4
45
0.140
2.40
0.97
1
nd
21
0.094
2.52
0.99
2
Avicennia marina
<35
22
0.308
2.11
0.97
3
Rhizophora apiculate
<28
57
0.235
2.42
0.98
4
nd
nd
0.171
2.52
0.98
5
Rhizophora mangle
nd
17
0.178
2.47
0.98
2
Bruguiera gymnorrhiza
2–21
17
0.186
2.31
0.99
6
Bruguiera parviflora
2–21
16
0.168
2.42
0.99
6
Ceriops australis
2–18
26
0.189
2.34
0.99
6
Xylocarpus granatum
3–17
15
0.082
2.59
0.99
6
Belowground
Avicennia marina
<35
14
1.28
1.17
0.80
3
Rhizophora apiculate
<28
11
0.00698
2.61
0.99
4
Rhizophora stylosa
<15
5
0.261
1.86
0.92
3
Bruguiera exaristata
<10
9
0.302
2.15
0.88
3
Xylocarpus granatum
<8
6
0.145
2.55
0.99
7
References: 1, Fromard et al. (1998); 2, Imbert and Rollet (1989); 3, Comley and McGuinness
(2005); 4, Ong et al. (2004); 5, Putz and Chan (1986); 6, Clough and Scott (1989); 7, Poungparn
et al. (2002)
nd no data
T. Inoue
difficulty of extracting roots from the muddy soils. Different allometric equations
for aboveground biomass are used for different mangrove species (Tam et al. 1995;
Ong et al. 2004; Comley and McGuinness 2005) and sometimes at different forest
sites (Clough et al. 1997), although Ong et al. (2004) applied similar equations to
two different Rhizophora apiculata forest sites. Komiyama et al. (2005) developed
the following universal allometric equation for mangrove trees with a trunk diameter of <49 cm:
W above
DBH
= 0 251
2 46
.
.
r
(3.1)
where W above (kg dry weight) is the aboveground biomass, ρ is wood density (g cm
−3
),
and DBH is the trunk diameter at breast height (cm). They based this equation on
the pipe model, which relates biomass to the cross-sectional area of stems and
branches (Shinozaki et al. 1964), and the static plant form model, an extension of
the pipe model (Oohata and Shinozaki 1979). Wood density of mangroves varies,
depending on the species, from 0.486 to 0.980 g cm
−3
(Putz and Chan 1986; Clough
and Scott 1989). A comparative analysis of reported allometric equations (using
mainly data obtained in Southeast Asia) showed that estimates of aboveground biomass obtained by using the universal equation are the same, within a 10% relative
error, as estimates obtained by using site-specific equations (Komiyama et al. 2008).
Table 3.5 Mangrove biomass estimated as W above or below = A DBH
B
, where W is biomass (kg dry
weight) and DBH is diameter at breast height
Species
DBH (cm)
n
A
B
r
2
References
Aboveground
Avicennia germinans
<4
45
0.140
2.40
0.97
1
nd
21
0.094
2.52
0.99
2
Avicennia marina
<35
22
0.308
2.11
0.97
3
Rhizophora apiculate
<28
57
0.235
2.42
0.98
4
nd
nd
0.171
2.52
0.98
5
Rhizophora mangle
nd
17
0.178
2.47
0.98
2
Bruguiera gymnorrhiza
2–21
17
0.186
2.31
0.99
6
Bruguiera parviflora
2–21
16
0.168
2.42
0.99
6
Ceriops australis
2–18
26
0.189
2.34
0.99
6
Xylocarpus granatum
3–17
15
0.082
2.59
0.99
6
Belowground
Avicennia marina
<35
14
1.28
1.17
0.80
3
Rhizophora apiculate
<28
11
0.00698
2.61
0.99
4
Rhizophora stylosa
<15
5
0.261
1.86
0.92
3
Bruguiera exaristata
<10
9
0.302
2.15
0.88
3
Xylocarpus granatum
<8
6
0.145
2.55
0.99
7
References: 1, Fromard et al. (1998); 2, Imbert and Rollet (1989); 3, Comley and McGuinness
(2005); 4, Ong et al. (2004); 5, Putz and Chan (1986); 6, Clough and Scott (1989); 7, Poungparn
et al. (2002)
nd no data
T. Inoue