90
vogelii Planch., Bambusa vulgaris Schrad. ex J.C. Wendn., Cocos nucifera L.,
Cynometra mannii Oliv., Dalbergia ecastaphylum (L.) Taub., Drepanocarpus lunatus GFW Meyer, Elaeis guinensis Jacq., Eremospatha wendlandiana Dammer ex
Becc., Hibiscus tiliaceus L., Guibourtia demeusei (Harms) J. Léonard, Ormocarpum
verrucosum P. Beauv., Pandanus candelabrun P. Beauv., Paspalum vaginatum Sw,
Phoenix reclinata Jacq., Raphia palma-pinus (Gaertn.) Hutch., Sesuvium portulacastrum L., etc.
The diversity in mangrove ecosystems can be expressed in terms of types of
vegetation encountered. The flora of the Wouri river estuary mangrove is made in
the suburban area of monospecific stations dominated widely by Rhizophora spp.
while Avicennia germinans and especially Nypa fruticans succeeded in large deforested areas. The next group, a blend of trees, shrubs, palms and grass, appears more
diversified, consisted of Acrostichum aureum, Cynometra mannii, Dalbergia ecastaphyllum, Drepanocarpus lunatus, Hibiscus tiliaceus, Ormocarpum verrucosum,
Pandanus candelabrum, Phoenix reclinata, Raphia palma-pinus, etc. which are
associations of plants generally observed along the edges slightly muddy (Din 2001;
Nfotabong-Atheull et al. 2013).
In the peri-urban areas, mangroves are converted into agricultural fields in which
there are species such as Zea mays L., Phaseolus vulgaris L., Elaeis guineensis
Jacq., Musa spp., Saccharum officinarum L. Other observations show that change of
land use promotes presence of unusual species. This is among other: Paspalum vaginatum, Anthocleista vogelii, Sesuvium portulacastrum, and Alchornea cordifolia.
The presence of these species in the intertidal zone is justified by physicochemical
changing properties of the soil due to scarcity of water in these places once regularly
flooded (Nfotabong-Atheull et al. 2013).
The structure of mangrove forest always characterizes this ecosystem worldwide
by an organization of vegetation based on distinct bands or zones, parallel to the
shore of the main water channel and each zone usually dominated by a single plant
species or rarely a combination of two plant species (Tomlinson 1986; Din 2001;
Marchand 2007; Din and Baltzer 2008; Nfotabong-Atheull 2011). The structure of
the Wouri river estuary mangroves is especial in the dimensions of trees (Fig. 3.4).
Rhizophora species have trees which can grow up to 50 m height in mature and
undisturbed forest while Avicennia germinans trees have shown diameters upon
100 cm (Din and Baltzer 2008; Din et al. 2002).
In many places, mangrove ecosystems of the Wouri river estuary have presented
a complete progressive series from pioneer stage to almost climax stands. The physiognomy of mangrove vegetation has been characterized by four landscapes
(Fig. 3.5):
1. the pioneer vegetation is consisted of Rhizophora seedlings and shrubs which
grow on an unstable substrate in the accretion areas installed in the center or on
the edges of the river and channels. After the depletion of the mangrove forest, a
recolonization is observed on abandoned and temporally flooded areas. Nypa
fruticans generally dominated this stage and the evolution led to transform the
original mangrove vegetation features;
N. Din et al.
vogelii Planch., Bambusa vulgaris Schrad. ex J.C. Wendn., Cocos nucifera L.,
Cynometra mannii Oliv., Dalbergia ecastaphylum (L.) Taub., Drepanocarpus lunatus GFW Meyer, Elaeis guinensis Jacq., Eremospatha wendlandiana Dammer ex
Becc., Hibiscus tiliaceus L., Guibourtia demeusei (Harms) J. Léonard, Ormocarpum
verrucosum P. Beauv., Pandanus candelabrun P. Beauv., Paspalum vaginatum Sw,
Phoenix reclinata Jacq., Raphia palma-pinus (Gaertn.) Hutch., Sesuvium portulacastrum L., etc.
The diversity in mangrove ecosystems can be expressed in terms of types of
vegetation encountered. The flora of the Wouri river estuary mangrove is made in
the suburban area of monospecific stations dominated widely by Rhizophora spp.
while Avicennia germinans and especially Nypa fruticans succeeded in large deforested areas. The next group, a blend of trees, shrubs, palms and grass, appears more
diversified, consisted of Acrostichum aureum, Cynometra mannii, Dalbergia ecastaphyllum, Drepanocarpus lunatus, Hibiscus tiliaceus, Ormocarpum verrucosum,
Pandanus candelabrum, Phoenix reclinata, Raphia palma-pinus, etc. which are
associations of plants generally observed along the edges slightly muddy (Din 2001;
Nfotabong-Atheull et al. 2013).
In the peri-urban areas, mangroves are converted into agricultural fields in which
there are species such as Zea mays L., Phaseolus vulgaris L., Elaeis guineensis
Jacq., Musa spp., Saccharum officinarum L. Other observations show that change of
land use promotes presence of unusual species. This is among other: Paspalum vaginatum, Anthocleista vogelii, Sesuvium portulacastrum, and Alchornea cordifolia.
The presence of these species in the intertidal zone is justified by physicochemical
changing properties of the soil due to scarcity of water in these places once regularly
flooded (Nfotabong-Atheull et al. 2013).
The structure of mangrove forest always characterizes this ecosystem worldwide
by an organization of vegetation based on distinct bands or zones, parallel to the
shore of the main water channel and each zone usually dominated by a single plant
species or rarely a combination of two plant species (Tomlinson 1986; Din 2001;
Marchand 2007; Din and Baltzer 2008; Nfotabong-Atheull 2011). The structure of
the Wouri river estuary mangroves is especial in the dimensions of trees (Fig. 3.4).
Rhizophora species have trees which can grow up to 50 m height in mature and
undisturbed forest while Avicennia germinans trees have shown diameters upon
100 cm (Din and Baltzer 2008; Din et al. 2002).
In many places, mangrove ecosystems of the Wouri river estuary have presented
a complete progressive series from pioneer stage to almost climax stands. The physiognomy of mangrove vegetation has been characterized by four landscapes
(Fig. 3.5):
1. the pioneer vegetation is consisted of Rhizophora seedlings and shrubs which
grow on an unstable substrate in the accretion areas installed in the center or on
the edges of the river and channels. After the depletion of the mangrove forest, a
recolonization is observed on abandoned and temporally flooded areas. Nypa
fruticans generally dominated this stage and the evolution led to transform the
original mangrove vegetation features;
N. Din et al.