Ecological Niche Total role of an organism in the environment. Fundamental Niche:Maximum niche a species can occupy,competition absent. Realized Niche:Portion of the fundamental niche occupied by the species, competition present. The full range of environmental conditions(biological and physical)under which an organism can exist describes its fundamental niche As a result of pressure from,and interactions with,other organisms (e.g. superior competitors),species are usually forced to occupy a niche that is narrower than this,and to which they are mostly highly adapted.This is termed the realized niche. Ecological Niche Ecological Niche Total role of an organism in the environment. Fundamental Niche: Maximum niche a species can occupy, competition absent. Realized Niche: Portion of the fundamental niche occupied by the species, competition present. The full range of environmental conditions (biological and physical) under which an organism can exist describes its fundamental niche. As a result of pressure from, and interactions with, other organisms (e.g. superior competitors), species are usually forced to occupy a niche that is narrower than this, and to which they are mostly highly adapted. This is termed the realized niche