Final answer:
A plant is part of both a community and an ecosystem. For the rabbit colony scenario, the population versus time graph will show a decrease to the carrying capacity as resources become limited.
Step-by-step explanation:
The thing that is part of both a community and an ecosystem is a plant. Plants are key components within both communities and ecosystems, as they play a fundamental role in providing energy through photosynthesis, habitat structure, and influencing the flow of water and nutrients.
When a colony of rabbits migrates to an ecosystem with a carrying capacity below the population of the colony, the shape of its population versus time graph will be a curve that decreases to the carrying capacity. This is because as resources become limited, competition for those resources increases and the growth rate decreases. The population will eventually adjust to the maximum number that the ecosystem can support sustainably, which is the carrying capacity.