Definition: The range or spectrum of environmental conditions and habitat characteristics that support the normal activity of an organism.
Source: Rickleffs, R.E. 1990. Ecology (3rd Edition). New York: W.H. Freeman & Co Ltd.
By Laura Klappenbach, About.com Guide
Source: Rickleffs, R.E. 1990. Ecology (3rd Edition). New York: W.H. Freeman & Co Ltd.