A biome is an area classified according to the species that live in that location. Temperature range, soil type, and the amount of light and water are unique to a particular place and form the niches for specific species allowing scientists to define the biome. However, scientists disagree on how many biomes exist. Some count six (forest, grassland, freshwater, marine, desert, and tundra), others eight (separating two types of forests and adding tropical savannah), and still others are more specific and count as many as 11 biomes.