Each of these regions has a community of plants that is unique to that climatic region. The term biome is used to identify these plant communities. Plant growth in a biome is determined by all of the above factors. However, any one of the factors may limit which plants can survive there. If, for example, an area receives only ten centimetres of rainfall a year, only certain plants can grow there.
Temperature can also be a limiting factor.
For instance, deciduous trees cannot withstand extremely cold temperatures and therefore are not found in the boreal forests that experience long periods of freezing temperatures each year. Ecologists have identified at least eleven different biomes in the world. In most cases the biomes are named for the dominant plants found in the climatic region. There is some disagreement over the exact number of biomes. Some ecologists want to split some biomes into two or more smaller biomes, while other ecologists feel the area is a single biome.