In ecology, what is an ecosystem?

An ecosystem is defined as a community of living organisms interacting with their environment. This includes not only the various species of plants and animals that inhabit a particular area but also the non-living components of their environment, such as air, water, soil, and climate. The interactions within an ecosystem can be complex and involve processes like energy flow, nutrient cycling, and the relationships among various organisms, including predation, competition, and symbiosis.

The other options focus on specific aspects that do not encompass the entire concept of an ecosystem. For instance, a group of the same species living in a particular area describes a population rather than an ecosystem, which requires the inclusion of different species and their interactions. Geological features pertain more to the physical landscape and do not address the biological and ecological interactions. Lastly, a collection of abiotic factors alone ignores the vital biotic interactions (living organisms) that are fundamental to defining an ecosystem. Thus, the correct answer captures the holistic nature of ecosystems, emphasizing the unity of living organisms and their physical environment.