Ecological Niche

Ecological Niche REMEMBER The habitat is an organism’s address. The ecological niche is its profession.

Explain More the niche is the “role” the species plays in the community of interacting species. This includes: Where it lives What it eats How it responds to stress What limits its population growth. It is the whole of the organism’s use of the biotic and abiotic resources in its environment.

Fundamental Niche This refers to the resources a population could theoretically use in an ideal situation.

Realised Niche This refers to the resources a population can actually use (remember it is affected by all the interactions with other organisms).

Example 2 species of barnacle grow on the rocky shore. Balanus balanoides and Chthamalus stellatus C. stellatus, which are smaller, live at the top of the rocks, while the B. balanoides, the larger, live lower down. The bigger barnacles can’t stand the period of dryness when the tide goes out, the small barnacles can.

Example If you remove all the B. balanoides from lower down, the smaller ones, C. stellatus, move quickly in and are very happy there. It’s just that they normally can’t stand the competition from the bigger barnacles. The fundamental niche for the small barnacle is the whole of the rock, but its realised niche is the upper layers of the rock.

Barnacles