45
0
200
400
600
800
OC [µmol (g bulk sediment) ]
0
50
100
150
200
250
0
200
400
600
13 C OC
0
400
800
1200
a
b
c
d
0
40
80
120
160
Density fraction [g cm ]
13 C OC
0
100
200
300
0
40
80
120
160
0
40
80
120
OC [µmol (g bulk sediment) ]
e
f
g
h
Fig. 2.4 The concentration and
δ
13
C of sediment OC in particle density fractions. (a) Temperate, non-estuarine Zostera marina
meadow, (b) estuarine Z.
marina
meadow, (c) unvegetated area among Z. marina
meadows, and (d) shallow (16 m) pelagic sediment of the Seto Inland Sea, Japan; (e) Subtropical
Thalassia hemprichii
meadow on carbonate sediment, (f) Enhalus acoroides
meadow on carbonate sediment, (g) E. acoroides
meadow on clastic sediment
around Ishigaki Island, southwestern Japan; and (h) mangrove-fringed, tropical E. acoroides
meadow on clastic sediment near Kuraburi, southern Thailand.
Note that the scale of the OC concentration axis differs among the panels. (Data source: (a–d) Miyajima et al. (2017); (e–h) Miyajima et al., unpublished data)
2 Carbon Sequestration in Sediment as an Ecosystem Function of Seagrass Meadows