Interdependence and Competition


All organisms interact with one another in various ways. The rise or fall in the population of one organism will affect other organisms in the ecosystem. For example, let’s look at a simple food chain:

Grass Grasshopper Bird

The grasshopper interacts with both the grass it consumes and the bird that preys on it.

If the population of birds that prey on the grasshopper declines, this will increase the population of grasshoppers. As a result, the quantity of grass will decrease, because more grasshoppers consume it.

However, in reality, these relationships are more complicated. The grasshopper will likely have other predators and more sources of food. This complexity means that a change in the ecosystem can be difficult to predict. However, even small changes to an ecosystem can lead to significant consequences.

Species within a community rely on each other, a relationship known as interdependence.


Competition is one of the most important processes in an ecosystem. To survive and reproduce, there are certain resources organisms need to compete for. For animals, this includes food, water, mates and territory. In contrast, plants compete for light, water, space and mineral ions.

An organism that has more resources is more likely to survive and reproduce.

There are two types of competition:

  • Interspecific competition – The competition between individuals of different species.
  • Intraspecific competition – The competition between individuals from the same species.

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