biome A biome is an ecosystem which is undergoing climactic ecological succession. LTER:809 EcoLexicon:biome In this definition, there is an assumption that no major perturbations are occurring or have occurred in a time frame affects the successional dynamics of the ecosystem. A "major" perturbation is one which disrupts the community's ability to restore its (near) equilibrium. Usually, pioneer or early secondary successional processes would be in effect in such scenarios. major habitat type astronomical body part geophysical entity ecosystem