Biology Reference
In-Depth Information
Concerning the other point made by Rosenzweig, that the system as
a whole cannot get out of control even if species at other trophic levels
are added, because it must be supported by the same resource base, it has
been shown by several authors that vacant niches exist in various systems
which lend themselves to colonization even if the resource base as a
whole does not expand. In other words, resources are not exhausted.
Moreover, why should there not be an increase in diversity by subdivi-
sion of niches? It is the aim of the following chapters to provide detailed
support for these assertions, and to evaluate the relative importance
of equilibrium and nonequilibrium by providing evidence suggesting
equilibrium and nonequilibrium conditions over evolutionary time and
in extant ecological systems.
