種多様性
Moisture and temperature are major physical drivers of natural ecosystems. The more arid and colder conditions found at higher northern latitudes (and high elevations elsewhere) support tundra and boreal forests. The water in this region is generally frozen and evaporation rates are very low. Species diversity, nutrient availability, precipitation, and average temperatures increase as you move from the tundra to boreal forests and then to deciduous temperate ecosystems, which are found south of these Arctic biomes.