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： sediment that accumulates in the flat or very gently sloping areas of the deep ocean basin floor. The three main types are siliceous oozes, calcareous oozes, and red clays.
定義： A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)
