Features
Certain principles that apply to a stable ecosystem must be in place to maintain that stability. Biodiversity among plants, animals and microorganisms must be maintained. Also, ecosystems must be able to dispose of waste and replenish nutrients, use sunlight as energy and maintain populations of consumer organisms so that overgrazing does not occur.
Factors Affecting Stability
A number of factors can easily affect stability in an ecosystem. These include in increase in the frequency of natural or unnatural disturbances, an abrupt change in species diversity or a change in the rate of nutrient and energy consumption. An ecosystem's resistance to disturbances and its ability to recover after a disturbance helps it to regain stability quickly when it is lost.
Considerations
While many stable ecosystems appear to be stagnant, with the same species and general appearance, that is not the case. Ecosystems are always adapting to even the slightest of environmental changes, making them highly dynamic structures.