What is an ecosystem?

An ecosystem is a community of interacting organisms and their physical environment. This definition encompasses the dynamic relationships among various living organisms, such as plants, animals, and microbes, as well as the non-living components like air, water, soil, and climate. These elements work together as a system, where energy flows and nutrients cycle through the ecosystem, facilitating interactions that support life.

Recognizing that an ecosystem includes both biotic (living) and abiotic (non-living) factors is key to understanding how different species interact with each other and their surroundings. For instance, the availability of sunlight, water, and nutrients can influence the types of organisms that thrive in an ecosystem, while the organisms themselves contribute to the health and stability of their environment through various processes such as photosynthesis, decomposition, and nutrient cycling.

The other definitions do not capture this complexity. A stable environment with no changes in species overlooks the natural processes of evolution and succession that can alter an ecosystem over time. A collection of non-living things focuses too narrowly on the abiotic components without acknowledging the vital role of living organisms. Lastly, limiting the definition to a group of organisms of the same species fails to consider the interactions between different species and the environment that define an ecosystem.