How is an ecosystem defined?

An ecosystem is defined as a community of organisms interacting with their environment. This definition encompasses not just the living organisms, such as plants, animals, and microorganisms, but also the non-living components of the environment, including air, water, soil, and climate. The interactions that take place within an ecosystem are vital, as they include processes such as nutrient cycling, energy flow, and the relationships (both positive and negative) that organisms have with one another and with their surroundings.

In contrast to other options, which focus on more narrow aspects, this definition captures the complexity and interconnectivity of life forms and their environments. For instance, defining an ecosystem merely as a group of animals ignores the plants, fungi, and microbes that are equally important in maintaining the balance of the ecosystem. Similarly, characterizing it solely as a specific type of biome would limit the understanding of the dynamic interactions that can occur within any given biome. Lastly, defining an ecosystem as simply the physical environment of a species overlooks the critical interactions between organisms and their habitat, which are essential for survival and ecological balance.