The biome is characterized by climate, temperature, and rainfall. The climatic factors that intervene are the altitude, latitude, and types of soil. Latitude determines temperature and seasonality and defines polar, subpolar, temperate, subtropical and tropical climates. Precipitation and latitude determine wet, sub-humid, dry or seasonal, semi-arid and arid types. The altitude determines the basal, premontane, montane, alpine and snow types. And only soil types are a determining factor in the influence of climatic factors and their variation and behavior within the biome.