BIO205H5 Chapter Notes - Chapter 18: Ecological Niche, Interspecific Competition, Null Model
Document Summary
The conditions under which an organism can function successfully are the consequence of physiological, morphological, and behavioural adaptations. Adaptations define the fundamental niche of a species. Environmental conditions vary in both time and space. We can represent the fundamental niches of various species with bell shaped curves along an environmental gradient e. g. the availability of water or light for plants. The response of each species is defined in terms of its of its population density or abundance. Although fundamental niches overlap each species has limits beyond which it cannot survive. The distribution of fundamental niches along the environmental gradient represents a primary constraint on the structure of communities. For any given range of environmental conditions only a few species can survive, grow, and reproduce. Null model assumes that the presence and abundance of the individual species found in a given community are solely the result of the independent responses of each individual species to the prevailing physical environment.
