Page:Niger Delta Ecosystems- the ERA Handbook, 1998.djvu/44

What is the Environment? 3.6.9 THE EVOLUTION OF SPECIES

The divergence and extinction of species through natural selection.

3.6.10 A NICHE

The home of an organism in all its dimensions, or how it fits into and makes a living in its ecosystem.

3.6.11 A HABITAT

The viable Ecosystem that is required to sustain a species.

3.6.12 CONSERVATION

The wise use of resources and the management of the environment so that all species, including mankind, can survive in a viable Ecosystem.

3.7 PLANTS AND ANIMALS IN ECOSYSTEMS

Ecosystems can be described in terms of plants or of animals but because plants do not move, their relationship to the environment is different from that of animals.

The components of an environment which determine plant characteristics, species diversity and populations are water, temperature, mineral nutrition, and competition with other plants and animals.

Plant species create microclimates for themselves, for other plant species, and for animals. This is how life initially colonises hostile environments. A good example is the colonisation of beach ridges by Casuarina trees.

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