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8 ] Foundations of agro-zoocoenology
and relative abundances, but that animal “communities” were highly contingent
on what we now recognize as the species pool. In his view, communities
come into being via temporal development and evolution though the processes
of colonization and accommodation. Thus, Szelényi focused on what we now
call species assembly rules for communities rather than a static concept of
“societies”.
He explained that the central questions of animal “community” ecology are
why are the populations together and how do they coexist? This led to his
focus on the accommodations necessary for coexistence of predators and
prey (herbivores and plants) and of populations using the same resource. In
his view the answer to the second problem was competitive coexistence,
although nowadays we know that other processes may be involved. His
simplistic view is probably related to the ideological dominance of Gause’s
competitive exclusion principle at that time.
Be that as if may, Szelényi pointed out that all animal “communities” are
dependent on plants (and other primary producers) because all of the energy
used by animals originates from plants. However, as their communities are
not bound to the plant community (because of movement behavior and rapid
reproduction), there is no simple association between plant societies and
animal “communities”. Regarding the herbivore-plant interaction, he stated
“It is a generally accepted fact that the plant-based energy resources are, at
all times, in abundance relative to the animals consuming them.” From this,
he deduced that natural enemies are critical components of a “community”
by “controlling” populations of herbivores. These conclusions preceded an
identical argument in the much more famous “the world is green” hypotheses
developed by Hairston et al. (1960).
His investigations developed several other significant points. For example,
he framed trophic interactions around life-history stages, which has been
recently called for in modern trophic interactions. In this way, he suggested
that trophic interactions are individual- and stage-specific, rather than species
properties. A conclusion he reached from these ideas is that polyphagous
species may be functionally monophagous or oligophagous in actual
“communities,” again highlighting the contingent nature of animal
“communities.” He preceded the concept of ecosystem engineers when he
described animal activities that mirrored the creation of human settlements
and agriculture. In passing, he concluded that there were no empty niches
in a “community” as did Whitaker et al. (1973) and suggested that animal
communities comprised a number of components that were tied together as
did Root (1973).
Much of the work is devoted to distinguishing the idea of “animal
community” (which he calls zoocoenosis) from other concepts (e.g., biome,
biotope, ecotope, merotope, oecus, habitat, phytocoenosis, ecosystem,
biogeocoenosis, etc) and developing a rather complex set of terms in an