Flora

The most noteworthy features of mangrove forests, apart from their unique habitat, are: the relative paucity of the species comprising them; the arch-formed stilt roots of the Rhizophora spp.; the clusters of aerial roots or pneumatophores from other genera such as Avicennia and Sonneratia, which protrude from the ground in such numbers as to impede walking; the curious adaptation to the environment whereby the seeds of the Rhizophora spp. germinate on trees; as well as the high incidence of trees with lenticellated bark.

The mangrove forests are evergreen. The paucity of species occurring in them is due to the unusual conditions of their existence, since few plants are able to tolerate and flourish in saline mud and to withstand frequent inundation by seawater. They also differ from the inland forests in that certain species are practically gregarious over extensive areas. Apart from the Rhizophora spp., many of the principal species coppice readily. The flora that comprises arborescent species with forestry importance is confined to a few families, i.e. Rhizophoraceae, Combretaceae, Avicenniaceae/Verbenaceae, Meliaceae, Sonneratiaceae, Sterculiaceae, Euphorbiaceae, Theaceae and Pelliceriaceae. Other families are sparingly represented, chiefly in situations where the limits of the mangrove are not sharply defined.

In the supra-littoral and interterrestrial zone, where brackish water conditions prevail, there are species that occur in the mangrove habitat proper, but which are not restricted to it, e.g. Acrostichum aureum, A. speciosum and A. danaefolium. Recognizing this, Saenger et al. (1983) has divided the mangroves into two broad groups comprising theexclusive speciesthat are restricted to the mangrove habitat, and thenon-exclusive species, which may be important in the mangrove habitat, but are not restricted to it.

References
Saenger, P., Hegerl, E.J. & Davie, J.D.S. 1983. Global status of mangrove ecosystems. Commission on ecology papers No. 3. Gland, Switzerland, IUCN.


Extracted from
FAO. 1994. Mangrove forest management guidelines. FAO Forestry Paper No. 117. Rome.

last updated:  Saturday, May 14, 2005