Unit 5: The structure of the ecosystems                      1   2   3   4   5   6

6. Ecological niche and habitat

In the ecosystems, living beings occupy a habitat and an ecological niche. These two concepts are closely related but they are different.

- The habitat is the typical physical place where a species lives. This place provides

   the most favourable natural conditions the species needs to survive and develop:

   temperature, humidity, food, etc.

- An ecological niche is the role a species plays in an ecosystem. It describes

   how an organism  lives in an ecosystem: where it finds shelter, how it obtains

   food, how it finds mate, etc.

However, it is possible that two species occupy the same niche, but this situation cannot be permanent. If two species would have exactly the same needs (eat the same food, require the same temperature, and so on) they will compete with each other and the species which adapt best will exclude the other one. To avoid it the species develop adaptations aimed for  minimise competition.

For example, zebras and giraffes are herbivores that live in the same habitat, the savannah. They are adapted to explode the same resource, the plants, but giraffes feed on leaves at the top of the trees, while zebras feed on leaves at ground level. In this way they avoid to compete. The share the same habitat, but occupy different ecological niches.

6.1. Complete these chart:

6.2. Why is it impossible that two species share the same habitat?

        Can they share the same ecological niche?

6.3. Listen and choose the correct word in each case: