Definition: A tundra is a terrestrial biome which includes, across its spatial extent, only low-growing vegetation such as dwarf shrubs, sedges and grasses, mosses, and lichens. Tundra biomes rarely have monthly average temperatures above 10 degrees Celsius and have low evapotranspiration ratios.
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.