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.
Definition: An alpine condition is an environmental condition in which the monthly mean temperature is less than 10 degrees Celsius and which occurs at altitudes above the tree line and below the snowline.
Definition: A plain without trees (apart from those near rivers and lakes); it is similar to a prairie, although a prairie is generally considered as being dominated by tall grasses, while short grasses are said to be normal in the steppe. It may be semi-desert, or covered with grass or shrubs or both, depending on the season and latitude.
