150
Benthic Microftora, Periphyton and Plant Associations
Among the most common mangroves are several species of the genus
Rhyzophora, which prefer the muddy bottom permanetly covered with sea
water, while Bruguiera and Luminitzera prefer habitats covered by brackish
waters and isolated from the direct in inflow of sea water (Clough 1982).
The most common mangroves in the Indo-Pacific reefs are: Rhizophora
stylosa, R. mucronata, R. apiculata, Bruguiera gymnorhiza, B. parviflora,
Cariops tagal, C. decandra, Luminitzera littorea, Xylocarpus granatum,
Avicennia marina, and Sonneratia caseolaris. On Caribbean reefs are found:
Rhizophora mangre, R. harrisoni, R. racemosa, Avicennia tormentosa, A.
germinaus, A. schaueriana, Conocarpus erecta, and Laguncularia racemosa.
4.3.2 Zonal Distribution, Phytocoenes Composition
The distribution of reef bottom plant associations at normal cross sections
clearly reflect the zonal structure of the reef benthic communities (Van den
Hoeck et al. 1978; Norris and Bucher 1982). They include one or several
key plant species. In the zone of rocky littorals these are the macrophyte
species, which are able to fix firmly their thalloms to the rock surfaces, like
Ralfsia expansa, Enteromorpha iluthrata, Caulerpa sp., Laurencia
microcladata, Galaxaura squalida, Syringodium sp., Valonia sp., and
Botriocladia sp., On the sandy bottom of lagoons the key species are usually
the seagrasses, like Thalassia, Thalassionema, Zostera, and the green
calcareous alga Halimeda. The places of lagoonal bottom, covered with
rubble or with dead coral heads, often are dominated by seaweeds:
Sargassum, Penicillus, Dictyosphaeria, Valonia, Udotea, Dictyota. In the
patch reef zone, on patch-reefs and the surrounding sands and rubble the
algae Sargassum, Halimeda, Dictyota, Caulerpa, and Penicullus are most
abundant. The dead coral heads in this zone are covered with branching
coralline algae, such as Jania and Amphiroa. On the sandy submerged
bottom of reef flats Halimeda, Turbinaria, Cladophora, Pocockiella,
Gelidiella, Boodleea and the filamentous blue-green alga Schizothrix are
often dominating. At the stripes of solid flats exposed during the ebbs, the
most common are, as a rule, the crustose Corallinaceas: Porolithon,
Neogoniolithon, and Sporolithon. On upper windward reef slopes the
coralline algae Porolithon, Paragoniolithon, Amphiroa, Jania, as well as the
thallomic macrophytes Laurencia, Acetabularia, Microdiction, Homotrema,
Galaxaura, Boodlea, Halimeda, and Udotea are among the most common.
The biomass of 1-2 of the key species might comprise up to 95% of the
total (Table 4.17). The zonal composition and abundance of reef
macrophyte communities are definitely controlled by the conditions of
nutrients (especially of phosphorus supply) (Littler et al. 1991).
Van den Hoeck et al. (1978) described the distribution of common taxa of
seaweeds at the section across the barrier reef off Jamaica. The high degree
of their specialization and their affinity to definite reef biotopes was shown.
Benthic Microftora, Periphyton and Plant Associations
Among the most common mangroves are several species of the genus
Rhyzophora, which prefer the muddy bottom permanetly covered with sea
water, while Bruguiera and Luminitzera prefer habitats covered by brackish
waters and isolated from the direct in inflow of sea water (Clough 1982).
The most common mangroves in the Indo-Pacific reefs are: Rhizophora
stylosa, R. mucronata, R. apiculata, Bruguiera gymnorhiza, B. parviflora,
Cariops tagal, C. decandra, Luminitzera littorea, Xylocarpus granatum,
Avicennia marina, and Sonneratia caseolaris. On Caribbean reefs are found:
Rhizophora mangre, R. harrisoni, R. racemosa, Avicennia tormentosa, A.
germinaus, A. schaueriana, Conocarpus erecta, and Laguncularia racemosa.
4.3.2 Zonal Distribution, Phytocoenes Composition
The distribution of reef bottom plant associations at normal cross sections
clearly reflect the zonal structure of the reef benthic communities (Van den
Hoeck et al. 1978; Norris and Bucher 1982). They include one or several
key plant species. In the zone of rocky littorals these are the macrophyte
species, which are able to fix firmly their thalloms to the rock surfaces, like
Ralfsia expansa, Enteromorpha iluthrata, Caulerpa sp., Laurencia
microcladata, Galaxaura squalida, Syringodium sp., Valonia sp., and
Botriocladia sp., On the sandy bottom of lagoons the key species are usually
the seagrasses, like Thalassia, Thalassionema, Zostera, and the green
calcareous alga Halimeda. The places of lagoonal bottom, covered with
rubble or with dead coral heads, often are dominated by seaweeds:
Sargassum, Penicillus, Dictyosphaeria, Valonia, Udotea, Dictyota. In the
patch reef zone, on patch-reefs and the surrounding sands and rubble the
algae Sargassum, Halimeda, Dictyota, Caulerpa, and Penicullus are most
abundant. The dead coral heads in this zone are covered with branching
coralline algae, such as Jania and Amphiroa. On the sandy submerged
bottom of reef flats Halimeda, Turbinaria, Cladophora, Pocockiella,
Gelidiella, Boodleea and the filamentous blue-green alga Schizothrix are
often dominating. At the stripes of solid flats exposed during the ebbs, the
most common are, as a rule, the crustose Corallinaceas: Porolithon,
Neogoniolithon, and Sporolithon. On upper windward reef slopes the
coralline algae Porolithon, Paragoniolithon, Amphiroa, Jania, as well as the
thallomic macrophytes Laurencia, Acetabularia, Microdiction, Homotrema,
Galaxaura, Boodlea, Halimeda, and Udotea are among the most common.
The biomass of 1-2 of the key species might comprise up to 95% of the
total (Table 4.17). The zonal composition and abundance of reef
macrophyte communities are definitely controlled by the conditions of
nutrients (especially of phosphorus supply) (Littler et al. 1991).
Van den Hoeck et al. (1978) described the distribution of common taxa of
seaweeds at the section across the barrier reef off Jamaica. The high degree
of their specialization and their affinity to definite reef biotopes was shown.