Answer/ Explanation
A sustainable ecosystem or biome is one in which the network of organisms can support themselves over long periods of time.
This usually means they are diverse, with all the elements required for the organisms to survive. This includes lots of different species, all working together in their separate ecological niches to maintain a balance in the ecosystem.
There will be adequate producers to provide food, herbivores, primary, secondary, and potentially even tertiary predators. There will also be decomposers present to recycle nutrients.
Other important features include sufficient space for the organisms to survive in their required habitats, a sufficient water supply for all organisms, and limited human activity to prevent interruptions.