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.
Comment: Preliminary definition. The semantics and definitions of "mediterranean", "subtropical", "tropical", "temperate", "polar", and similar climate types may be transferred to an "environmental condition" class once the semantics of this class have been established.
Definition: A mixed forest biome is a forest biome which contains densely packed populations or communities of broadleaf and coniferous trees, strongly limiting light penetration to the forest floor.