Billy Brown writes:
> Agricultural production requires only that we successfully grow a
> few dozen plant species in an environment where temperature, light
> levels and atmosphere composition are all subject to direct external
> control. This will, of course, require that we support a small
> variety of insects and microorganisms that are essential to the
> survival of said plants, but you don't need a complete ecosystem.
> As long as you can maintain the system in a stable state with a
> reasonable amount of human intervention you're in good shape.
Again, if it's going to be functioning in space, with a closed boundary, with living organisms in it, then it *is* a complete ecosystem. The question is not whether or not you need a complete ecosystem, the question is whether the ecosystem you construct will flourish or die.
The system you describe, a closed system with just a few species, has actually been attempted in early closure experiments. It proved, empirically, unstable. So I don't know why you feel that we already know how to do this when past attempts to do so have failed.
> The "Biosphere" approach, in contrast, requires that you create a
> completely self-sustaining ecology. You end up with at least an
> order of magnitude increase in the number of species involved, lots
> of extra biomass, and an unmanageable mess of interlocking feedback
> loops that are almost impossible to manage. Making it work at all
> will be far more difficult than in the agriculture approach, and
> making it produce food with any reasonable efficiency will be nearly
> impossible.
-- arkuat