What factors cause variations in climate and vegetation in the US?

Climate has a major impact on the variety and distributions of vegetation in the West. Temperature and moisture levels are the two major variables that determine the types of vegetation in a region and the West generally experiences warmer drier climates which limits the types of vegetation that can grow there. In the West climate determines the presence of deserts grasslands coniferous forests and temperate rainforests. Because of the wide range of climates the West can be home to a variety of vegetation including:

• Cacti and other succulents in the driest regions
• Trees such as pines and junipers in the mountains
• Grasses shrubs and other low-lying plants in grasslands
• Tall evergreens in temperate rainforests

The distribution of vegetation in the West is also determined by climate. Areas with higher rainfall may support more diverse and plentiful vegetation while areas with lower rainfall may have less vegetation. Additionally the climate affects the type of vegetation that can be found in the region. For example deserts are found in areas with very little rainfall while temperate rainforests are found in areas with higher rainfall. The variety and distributions of vegetation in the West are ultimately determined by the climate of the region.