Community ecologists seek to
understand the mechanisms responsible for patterns of trophic structure by
observing communities during assembly. Here I present results from a test of a
modified version of the sequential dependency hypothesis by Holt et al. (1999).
Holt and colleagues suggest that a specialist predator's colonization success
is linked to prior successful colonization of its prey, and that generalist
species will be early arrivers because they are less trophically constrained.
Furthermore, predators require more area and energy on a per capita basis so
they should have higher densities per unit area in either large or enriched
plots relative to their prey. I observed sequential colonization of species
from four trophic levels of an aphid-predator food web module on plots of