biome

from WordNet (r) 3.0 (2006)

biome
    n 1: a major biotic community characterized by the dominant
         forms of plant life and the prevailing climate

from The Collaborative International Dictionary of English v.0.48

Biome \Bi"ome\ (b[imac]"[=o]m), n. [Gr. bi`os life.]
   1. (Ecology) a specific type of complex ecological community
      characterized by specific environmental conditions and a
      distinctive group of plants and animals, maintained in a
      relatively stable equilibrium, such as a {rain forest
      biome} or {prairie biome}.
      [PJC]

   2. a particular region which is a biome[1].
      [PJC]