The Brackish Ecozone
7 THE NATURAL BRACKISH-WATER ALLUVIAL EQUATORIAL MONSOON ECOZONE
- Introduction
- Mangrove Forests and their Distribution
- Plant Species Composition of the Nigerian Mangroves
- The Dynamics of Mangrove Ecology
- Food Chains of the BAM Ecosystem
- Animal Communities of the BAM Ecozone
- The Brackish-water/Freshwater Ecotone
7.1 INTRODUCTION
This ecozone is often referred to as 'the Mangroves'. However, as with the other ecozones of the Delta, we need a term that can apply to both the natural ecozone and its present-day situation as a human ecosystem. As mangrove forests have in many instances been damaged or cleared, we will again use the ERA terminology and refer to this ecozone as the Brackish-water Alluvial Tropical Monsoon, or BAM.
'Saltiness' is more accurately defined as the concentration of chlorine, being representative of the amount of salt (sodium chloride) that is in solution as sodium and chloride ions.
Seawater contains over 2.2% of Chlorine; water containing less than 0.03% is considered 'freshwater'.The ecozone extends from the Benin Estuary to the Sanaga Estuary in Cameroon, and in the original and natural ecosystem mangrove forest covered more than 95% of the area, the remaining portions being ecotones between Brackish and Fresh-water ecosystems.
7.2 MANGROVE FORESTS AND THEIR DISTRIBUTION
Human influence has been far less dramatic here than in other parts of the Niger Delta and much of the ecozone remains mangrove forest.
#The following conditions are necessary for the natural development of mangrove forests:
- tropical or sub-tropical tidal waters
- water-logged alluvial deposits
- a brackish water regime, lying between the high and low tide levels
- protection from the battering of oceanic waves
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