What term refers to all combined living and non-living components in a specific environment?

The term that encompasses all combined living and non-living components in a specific environment is "ecosystem." An ecosystem includes not only the various organisms—such as plants, animals, fungi, and microorganisms—but also the physical environment, which includes elements like water, soil, air, and climate. This definition highlights the intricate interactions that occur within these systems, where living organisms interact with each other and with their physical surroundings in complex ways.

In contrast, a biome is a larger classification of regions characterized by specific climate and ecological conditions, such as deserts or rainforests, and doesn't account for the specific interactions within a smaller area. A habitat refers more to the specific environment where an organism lives, but it doesn’t include all the interacting components. A niche describes the role or function of an organism within its environment, including its interactions with both biotic and abiotic factors, but again does not encompass all components of the ecosystem itself. Thus, "ecosystem" is the most comprehensive term among the options provided.