LIFESCI 1 Chapter Notes - Chapter 47: Ecological Niche, Soil Chemistry, Cestoda
Document Summary
Every species interacts with other species in ways that affect growth and reproduction. Associations among species, whether positive, negative, or neutral, form a complex web of interactions in which each species influences the population size and distribution of other species, whether they are partners, enemies, or food. A population persists only in places where its members can tolerate the physical environment. Competition between species can occur when different species use the same resources in the same place. This combination of a species" physical habitat and its ecological role in that habitat defines its niche. Nearly a century ago, the american ecologist joseph grinnell defined the niche as the sum of the habitat requirements needed for a species" survival and reproduction. Later, ecologist charles elton redefined the niche as the role a species plays in a community, switching emphasis from the habitat to the species itself.
