N-dimensional hypervolume concept refers to:
“Fundamental niche dimensions” for n-dimensional hypervolume concept refers to. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Habitat describes where an organism occurs; niche additionally describes how it obtains resources and affects or responds to other organisms. Distribution therefore provides evidence about a niche but is not identical to it. The remaining alternatives—“Habitat dimensions”, “Population density”, “Reproductive rate”—refer to different states, processes, or scales and theref
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 13
