Bottom Plant Associations
145
the seagrasses. The first two groups are the components of periphyton and
microphytobenthos, and have been reviewed above (d. Sect. 2.4.2). The
total number of thallomic macrophytes, represented by green, brown and
red algae, in phytocoenes of the open sea reefs attains 100-250, while in
reef areas near the continents, especially at the boundaries of tropics, it
could be twice as much (Table 4.13). As an example of the latter there are
the phytocenes of the Red sea reefs and of some atolls in the Indian ocean
(Fig. 4.5; Table 4.14). The benthic flora of coral reefs is taxonomically much
less abundant than that of the temperate coastal regions, where the total
number of species attains 700-1000. Among these groups of reef
macrophytes the poorest is the group of brown algae: 20-30 species
compared with 300 at temperate coasts. The total numbers of macrophyte
species in plant associations of separate reef systems of atolls varies within 5
to 70, while in those off the continental shelf 100 to 140 (Table 4.13). This
increase is connected mostly with stimulation of development in the latter of
the green algae, many of which prefer biotopes enriched with nutrients and
organic matter, which arrive from land and from mangroves (Riitzler and
Macintyre 1982).
The green algae (Chlorophyta) are represented on reefs largely by
specialized calcareous algae from the genera Halimeda, Penicillus, and
Udotea, as well as by the filamentous algae Cladophora and Chaetomorpha.
Halimeda is the most widespread reef calcareous alga with hard thalloms
heavily incrusted with lime. It may attach to solid rocks and to anchor to the
Table 4.13. Number of species of basic taxa in phytocoenes of different reef regions
compared with the temperate coasts of the British Islands and of southern Australia.
(After Bakus 1969; Riitzler and Macintyre 1982; Gribb 1973; Vinogradova and KaluginaGutnik 1985)
Region
Chlorophyta Phaephyta Rhodophyta Total number
of species
Bermuda
59
23
63
145
Florida
143
55
216
414
Belize
73
32
124
239
Islands of the Indian Ocean
50
26
46
122
South Vietnam
97
60
154
311
Maldives
28
8
22
58
Gilberts
21
5
29
55
Haluk atoll (Carolines)
46
3
37
86
Marshalls
108
24
117
249
Hawaii
21
8
35
64
Philippines
74
29
109
219
Solomons
243
Great Barrier Reef of Australia
230
(southern part)
British Islands
198
198
353
749
Southern Australia (temperate
94
191
725
1010
zone)
145
the seagrasses. The first two groups are the components of periphyton and
microphytobenthos, and have been reviewed above (d. Sect. 2.4.2). The
total number of thallomic macrophytes, represented by green, brown and
red algae, in phytocoenes of the open sea reefs attains 100-250, while in
reef areas near the continents, especially at the boundaries of tropics, it
could be twice as much (Table 4.13). As an example of the latter there are
the phytocenes of the Red sea reefs and of some atolls in the Indian ocean
(Fig. 4.5; Table 4.14). The benthic flora of coral reefs is taxonomically much
less abundant than that of the temperate coastal regions, where the total
number of species attains 700-1000. Among these groups of reef
macrophytes the poorest is the group of brown algae: 20-30 species
compared with 300 at temperate coasts. The total numbers of macrophyte
species in plant associations of separate reef systems of atolls varies within 5
to 70, while in those off the continental shelf 100 to 140 (Table 4.13). This
increase is connected mostly with stimulation of development in the latter of
the green algae, many of which prefer biotopes enriched with nutrients and
organic matter, which arrive from land and from mangroves (Riitzler and
Macintyre 1982).
The green algae (Chlorophyta) are represented on reefs largely by
specialized calcareous algae from the genera Halimeda, Penicillus, and
Udotea, as well as by the filamentous algae Cladophora and Chaetomorpha.
Halimeda is the most widespread reef calcareous alga with hard thalloms
heavily incrusted with lime. It may attach to solid rocks and to anchor to the
Table 4.13. Number of species of basic taxa in phytocoenes of different reef regions
compared with the temperate coasts of the British Islands and of southern Australia.
(After Bakus 1969; Riitzler and Macintyre 1982; Gribb 1973; Vinogradova and KaluginaGutnik 1985)
Region
Chlorophyta Phaephyta Rhodophyta Total number
of species
Bermuda
59
23
63
145
Florida
143
55
216
414
Belize
73
32
124
239
Islands of the Indian Ocean
50
26
46
122
South Vietnam
97
60
154
311
Maldives
28
8
22
58
Gilberts
21
5
29
55
Haluk atoll (Carolines)
46
3
37
86
Marshalls
108
24
117
249
Hawaii
21
8
35
64
Philippines
74
29
109
219
Solomons
243
Great Barrier Reef of Australia
230
(southern part)
British Islands
198
198
353
749
Southern Australia (temperate
94
191
725
1010
zone)