The five major biomes on Earth are aquatic, tundra, forest, desert and grassland. The most basic division of biomes is into aquatic and terrestrial or land. A biome is characterized as areas of the world that have similar temperature and weather patterns and also contain many similar or related species of animals.
Many scientists believe that splitting the world into only five groups is simplifying things a bit too much and instead choose to further break down these major biomes into many smaller subgroups. For instance, some scientists split the forest biome into temperate forest, rainforest, taiga and chaparral, while others make a further distinction between deciduous and coniferous forests. Grasslands can also be divided up into savanna and temperate grasslands, while the aquatic biome needs to be split between marine and freshwater. Some scientists think further dividing is necessary for the aquatic biome, adding additional designations for into coral reefs, estuaries and freshwater wetlands biomes. Many also choose to list a separate alpine biome, as some of its characteristics do not fit into any of the five major biomes. However, it resembles the tundra in some aspects due to its low temperatures, but it also shares characteristics with other biomes.