An ecological niche is shorthand for how an organism fits into its place in nature. It includes not only the environment where an organism lives, but the various aspects of the natural history of the organism. Thus the ecological niche of, say, a kangaroo rat includes not only the topography, vegetation, other animals, climate, and so forth, but also how it makes its living, how it defends itself, and its reproductive strategy.
If we constructed a multidimensional model taking into account all the
factors involved in the ecological niche of a particular organism, adding a dimension
for each factor, we would end up confining a niche space, the hypervolume. The organism
could survive anywhere within the mathematical boundaries of the hypervolume. This
niche is the one actually inhabited and termed the "realized niche". However,
we need another term, too, for survivable conditions present nowhere today. For
example, during the last ice age, animals lived in plant communities no longer in
existence. That we can visualize this, what we call the fundamental niche, really
requires thinking outside the box.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.