Page:Niger Delta Ecosystems- the ERA Handbook, 1998.djvu/80

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The Freshwater Ecozone

6 THE NATURAL FRESHWATER ALLUVIAL EQUATORIAL MONSOON ECOZONE

  • Introduction
  • The Complexity of the natural FAM Ecosystems
  • Palms and Other Vegetation
  • Sub-Ecozones of the FAM Ecozone
  • Animals Communities of the FAM


6.1 INTRODUCTION

The FAM Ecozone is often referred to as tropical rainforest, fresh-water swamp or simply swamp, but these descriptions can be misleading. Palm forest, rather than the more classic LEM rainforest, covers much of the area, and at times much of the land may be dry or only temporarily waterlogged.

However, as we have discussed, water is always a limiting factor to plant growth and the freshwater regime is the distinguishing factor of this ecozone. It shares the equatorial monsoon climate of the whole Niger Delta, and together with the alluvial nature of its soils and topography this gives it the ERA name Fresh-water Alluvial Equatorial Monsoon (FAM) or 'the freshwater ecozone'.

Within the natural fresh-water ecozone there are a number of well-defined sub-ecozones including:

#levee forest

#palm swamp

#seasonal swamp

#white-water flood-plain

#black-water flood-plain

#lakes and seasonal lakes

#seasonally exposed recent river alluvium

#rivers

There are also many ecotones, the most important being those between the swamps and drier land, and between the mangroves and the fresh-water ecosystems.


6.2 THE COMPLEXITY OF THE NATURAL FAM ECOSYSTEMS

The Fresh-water ecozone is a complex mosaic of dry, seasonally wet and wet ecosystems, and ecotones that reflect the equally complex soil patterns and Catena topography upon which they are based.

The predominant natural vegetation climax of most of the ecozone is tropical rainforest as considered in the previous chapter; however there is a different species mix, as the limited drainage causes waterlogging that cannot be tolerated by some of the plants common to the natural LEM rainforest.

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