What is the definition of an ecosystem?

The definition of an ecosystem encompasses both the living organisms (biotic factors) and their physical surroundings (abiotic factors) interacting in a specific environment. This interaction forms a complex web of life where energy is exchanged and nutrients are cycled.

In this context, the correct answer highlights that an ecosystem is made up of biological communities, which includes plants, animals, microorganisms, and their physical environment, which consists of soil, water, air, and climate. This relationship is vital for understanding ecological processes and how different components in nature are interconnected, leading to a balanced environment where organisms thrive together.

The other options lack this comprehensive definition of an ecosystem. For example, defining an ecosystem solely as a large geographical biotic community overlooks the critical role of abiotic components. Describing it merely as a linear sequence of energy flow reduces a complex system to a simple pathway, neglecting the multifaceted interactions involved. Lastly, referring to an isolated area with no living organisms contradicts the essential characteristic of an ecosystem, which is that it must include both living and non-living elements.