While on a walk through a forest, you notice birds in trees, earthworms in the soil, and fungi on plant litter on the forest floor. based on your observations, you conclude that each of these organisms occupies a different.

niche

Explanation:

Niche is a specific natural space occupied by a species of an organism in an ecosystem where the organism successfully interacts with biotic and abiotic factors making it to thrive and successfully make use of the resources in the space it occupies.  

The soil, as an ecological niche for the earthworm, has environmental conditions that favors the successful existence of the earthworm which plays an important functional role within the ecosystem.