What is an ecosystem primarily composed of?

An ecosystem is fundamentally composed of organisms and their environment. This includes all the living components, such as plants, animals, and microorganisms, as well as the non-living elements like air, water, soil, and climate that interact with these organisms. The relationships between these biotic (living) and abiotic (non-living) components are crucial for understanding how ecosystems function.

In this context, the living organisms depend on their environment for resources such as nutrients, light, and space, while the environment is influenced by the activities of these organisms. This intricate interplay shapes the structure and dynamics of the ecosystem, making it vital to consider both parts when studying ecosystems.

Other options, while they mention aspects that might relate to ecosystems, do not encapsulate the full definition. For example, solid and liquid substances are too broad and do not specifically refer to the living and non-living interactions. Living organisms alone miss the crucial role of their environment, and energy and matter, while important components of ecological processes, do not capture the necessary biotic and abiotic interactions that define an ecosystem.