A plethora of different theories, models, and concepts make up the field
of community ecology. Amid this vast body of work, is it possible to
build one general theory of ecological communities? What other
scientific areas might serve as a guiding framework? As it turns out,
the core focus of community ecology--understanding patterns of diversity
and composition of biological variants across space and time--is shared
by evolutionary biology and its very coherent conceptual framework,
population genetics theory. The Theory of Ecological Communities takes
this as a starting point to pull together community ecology's various
perspectives into a more unified whole.
Mark Vellend builds a theory of ecological communities based on four
overarching processes: selection among species, drift, dispersal, and
speciation. These are analogues of the four central processes in
population genetics theory--selection within species, drift, gene flow,
and mutation--and together they subsume almost all of the many dozens of
more specific models built to describe the dynamics of communities of
interacting species. The result is a theory that allows the effects of
many low-level processes, such as competition, facilitation, predation,
disturbance, stress, succession, colonization, and local extinction to
be understood as the underpinnings of high-level processes with widely
applicable consequences for ecological communities.
Reframing the numerous existing ideas in community ecology, The Theory
of Ecological Communities provides a new way for thinking about
biological composition and diversity.