The four main vegetation regions are forest, grassland, tundra and desert. Many scientists believe there are five classifications of vegetation regions, with the fifth one being ice sheet. This classification is often overlooked because Antarctica and Greenland are the only land masses on Earth that meet the requirements.
Vegetation regions have distinctive characteristics. They are categorized by the types of plants, soils and weather patterns that are commonly found in each region. The biggest factors that determine how an area is classified are its climate, soil, the ability of the soil to hold water and the slope of the land.