Final answer:
A tropical rainforest, desert, and the area surrounding a rotting log can all be considered ecosystems, as they encompass both biotic and abiotic components that interact within a specific area.
Step-by-step explanation:
An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows.
Ecosystems can be vastly different, ranging from large-scale geographical areas to a single log.
When considering the options provided, a tropical rainforest, desert, and the area surrounding a rotting log can all be considered ecosystems because they consist of both living organisms and nonliving elements interacting with each other in a distinct area.
These environments feature a dynamic interplay between plants, animals, microorganisms, soil, rocks, and the atmosphere. A tropical rainforest is known for its high biodiversity and complex structure involving numerous plant and animal species.
A desert may seem lifeless at a glance, but it hosts a variety of life adapted to its harsh conditions. The area around a rotting log is an ecosystem on a smaller scale, where decomposers break down the wood and recycle nutrients back into the soil, supporting other life forms.