定義: directly or indirectly modulating the availability of resources to other species, by causing physical state changes in biotic or abiotic materials; modifying, maintaining and/or creating habitats
定義: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
定義: The marine benthic biome (benthic meaning 'bottom') encompasses the seafloor and includes such areas as shores, littoral or intertidal areas, marine coral reefs, and the deep seabed.