Which of the following best illustrates the concept of an ecosystem?

The concept of an ecosystem refers to a community of living organisms interacting with one another and their physical environment, encompassing both biotic (living) and abiotic (non-living) components. The best illustration of this concept is found in a forest where plants, animals, and microorganisms interact closely with one another and the elements of their environment, such as soil, water, and climate.

In this scenario, the interconnections among various species demonstrate the complexity and dynamic nature of an ecosystem. The interactions such as predation, pollination, decomposition, and nutrient cycling contribute to the stability and health of the ecosystem. This intricate web of relationships showcases how different organisms rely on each other and their surroundings for food, shelter, and survival.

In contrast, the other options focus on limited interactions or components. A desert where only cacti grow lacks the diversity and complex interactions associated with a full ecosystem. A pond with only fish fails to capture the variety of life forms and their interactions, such as plants and microorganisms that are essential for a balanced ecosystem. Lastly, a city, while bustling with activity, represents a human-made environment that does not exemplify the natural interconnectedness seen in ecosystems. While cities do have biological components, they primarily serve as built environments