التعريف: 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
التعريف: 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.
التعريف: 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)
