Definition: A forest biome is a terrestrial biome which includes, across its entire spatial extent, densely packed vegetation which strongly limits light penetration to the forest floor.
Definition: A habitat that is in or on a body of water containing low concentrations of dissolved salts and other total dissolved solids (<0.5 grams dissolved salts per litre).
Definition: 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)