Trees of Arboretum West

Sierra Nevada West

Sierra forests are a diverse mix of trees and shrubs. In the lower elevations deciduous plants lose their leaves in the fall and regrow them the next long growing season. The shorter growing season at higher elevations requires evergreen trees to retain their needles as long as possible. A band at about 4000 ft (1220 m) elevation has the mildest climate and the greatest diversity of plants in the Sierra. The Sierra foothills are dominated by rapid runoff of winter rain and hot, dry summers. Shrubs and trees have adapted with tiny, light-colored, waxy leaves to prevent or reduce water loss. Many sprout from their bases after fires have swept the area. Fire is a major factor in excluding trees, maintaining the chaparral shrub community on the lower foothills. This is reinforced by the high mineral content of the soil along the Mother Lode Fault system of the Foothills.

Sierra Nevada East

Coast

The coastal forests are made possible by generous winter rains and summer fog. These keep the temperature mild and the climate damp. The coastal redwoods are the tallest trees in North America. Some of the more hardy trees such as tan oak, madrone and Kellogg's black oak also occur in the Sierra Nevada between 3000 and 5000 ft (915 to 1525 m).