The Ecological Niche

The concept of the ecological niche is an important one; it helps us to understand how organisms in an ecosystem interact with each other. The concept is described by Odum as follows:

The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism’s “address”, and the niche is its “profession”, biologically speaking.

Odum – Fundamentals of Ecology – W B Saunders 1959

Here are a few examples to help you understand what we mean when we (ecologists) use the term “ecological niche”:

Oak trees live in oak woodlands; that’s common sense. The oak woodland is the habitat. So if Odum was writing a letter to an oak tree he would address the letter to:

Sir Deciduous Oak Tree,
The Oak Forest,

What do oak trees do? If you can answer that question you know the oak trees “profession” or its ecological niche. Perhaps you think that oak trees just stand there looking pretty and not doing vey much, but think about it.

Oak trees:

  1. absorb sunlight by photosynthesis;
  2. absorb water and mineral salts from the soil;
  3. provide shelter for many animals and other plants;
  4. act as a support for creeping plants;
  5. serve as a source of food for animals;
  6. cover the ground with their dead leaves in the autumn.

These six things are the “profession” or ecological niche of the oak tree; you can think of it as being a kind of job description. If the oak trees were cut down or destroyed by fire or storms they would no longer be doing their job and this would have a disastrous effect on all the other organisms living in the same habitat.

Hedgehogs in my garden also have an ecological niche. They rummage about in the flowerbeds eating a variety of insects and other invertebrates which live underneath the dead leaves and twigs in the flowerbeds. That is their profession. They are covered in sharp spines which protect them from predators, so being caught and eaten is not a part of their job description.

However, hedgehogs cannot groom themselves properly. All those spines on their backs make a superb environment or microhabitat for fleas and ticks.

My hedgehogs put nitrogen back into the soil when they urinate! I don’t know how much nitrogen they put into the soil but it probably helps the plants if they do. I think that they eat my slugs, so that reduces the effect which slugs have on the flowers.

So the idea of an ecological niche is very simple. You just need to know where the animal or plant lives and what it does.