Comment: "Small" is ambiguous. For details on "Small rivers" (e.g. the Salween river) see http://worldwildlife.org/biomes/small-river-ecosystems. This class will be replaced with a less ambiguous class.
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: "Large" is ambiguous. For details on "Large rivers" (e.g. the Mekong river) see http://worldwildlife.org/biomes/large-river-ecosystems This class will be replaced with a less ambiguous class.
Definition: A transition zone between different physiogeographic provinces that involves an elevation differential, often involving high cliffs. Most commonly a transition from one series of sedimentary rocks to another series of a different age and composition. In such cases, the escarpment usually represents the line of erosional loss of the newer rock over the older.