A step in the movement of energy through an ecosystem is called a trophic level.

Here's why:

* Trophic levels describe the position of an organism in a food chain or web, based on how it obtains energy.

* Producers (like plants) make their own food through photosynthesis, forming the first trophic level.

* Consumers (like herbivores and carnivores) get their energy by eating other organisms, occupying higher trophic levels.

* Decomposers (like bacteria and fungi) break down dead organisms and waste, returning nutrients to the ecosystem.

Each trophic level represents a distinct step in the flow of energy through the ecosystem.