Final answer:
An association of populations of different species in the same area is known as a community, which together with abiotic factors, forms an ecosystem, and all ecosystems collectively make up the biosphere.
Step-by-step explanation:
An association of populations of different species living in the same area is called a community. For instance, in a forest, the community comprises various populations like those of pine trees, flowering plants, insects, and microbes. The forest with all these living components, along with abiotic factors like soil nitrogen and rainwater, forms an ecosystem.
On a much larger scale, the biosphere encompasses all ecosystems and includes every zone where life exists on Earth, encompassing land, water, and parts of the atmosphere.