Boom and bust
I think that would likely be the problem with limited, closed ecosystems. They would almost always go into an oscillation - boom or bust - but at some point the oscillation would go off-scale - that is, reach a point where everything collapses and nothing (except maybe a few bacteria) survives. Extensive human intervention might be able to keep this from happening in very small systems for shorter time spans, but the bigger the system, the harder it would be to control the oscillations - until you get up to planetary ecosystems, and even then there are catastrophic oscillations, which I think explains some of the major extinction events in the Earth's past.