Final answer:
A closed ecosystem experiences no input or output of energy or material, which is an artificial concept found in laboratory settings rather than naturally occurring systems. In contrast, most natural systems are open, with ongoing exchanges of energy and mass with the environment.
Step-by-step explanation:
The type of ecological system that experiences no input or output of energy or material is a closed ecosystem. In reality, closed ecosystems do not exist naturally, as most ecological systems are open with constant energy and matter exchange with their surroundings.
However, closed ecosystems can be artificially created in laboratory settings where all exchanges with the environment are strictly controlled.
Most systems we observe, including biological organisms and ecosystems, are open systems. They constantly exchange energy and mass with their environment. For example, organisms take in energy-storing molecules as food and release energy to the environment through various processes such as metabolism and movement.
Therefore, while closed systems theoretically exist as a concept, they are essentially an idealization rather than a natural occurrence in ecology.