Friday, August 21, 2009
The ecological splendor of the natural world came about through the repetition of a single theme: A resource that increases in abundance increases the fecundity of organisms that survive well within the environment under such abundance. These organisms then reduce the level of resource abundance through their own abundance, but create (or become) resources in the process. The degree to which this repetitive system stabilizes is directly proportional to the sensitivity of response and the number and variety of such systematic interactions, both of which increase with the biodiversity of the ecosystem. Generally speaking, only loop-shaped (and multi-looped) relationships trend toward a stable equilibrium, because A) The absence of closed loops (eg the arctic hare and fox) leaves the last species (in this case the fox) with only resource exhaustion as a check, seen as a repeating wave running from the beginning to the end of the chain (or sometimes from the end to the beginning); and B) Closed loops repeatedly transmit population imbalances back to the original resource species, creating a type of “surplus parity” in which standing reserves of resources come to exist within ecosystems, allowing incidental increases in constituent population levels to be smoothed out (initial consumption boost = residual increase in resource surplus).