The Redwood Transition, which comprises the coastal Red- 

 wood belt, extends from sea-level to 2,000 or sometimes to 3,000 

 feet (610 to 914 m) in altitude. It has, therefore, a very much 

 lower altitude than the Sierra Transition and a somewhat higher 

 rainfall, varying from 25 to 122 inches (64 to 310 cm). From the 

 standpoint of temperature it enjoys a lower annual range and 

 lower diurnal range. Being wholly within the coastal fog belt and 

 lying next to the ocean, it has much greater humidity. Proceeding 

 from the Central Valley to the coastal edge of the Redwood belt, 

 one passes through formations similar, in an ecological view, to 

 those met with in ascending the Sierra from the Central Valley, 

 since there are met successively the dry barren plains, the barren 

 foothills, the Chaparral, and finally a narrow band of Pinuspon- 

 derosa and Quercus kelloggii, which is characteristic of the Arid 

 Transition. In its greatest development. Coast Redwood forms 

 pure stands. In other parts of the belt it is dominant but with it 

 are associated Tan Oak (Lithocarpus densiflora) and Douglas Fir 

 (Pseudotsuga menziesii) and other conifers. On the inner side 

 of the Redwood belt is a marked band of Madrone {Arbutus men- 

 ziesii) and Douglas Fir. Herbs include Fetid Adder's Tongue 

 (Scoliopus bigelovii); Clintonia andrewsiana; False Lily-of-the- 

 Valley (Maianthemum dilatatum); Trillium ovamm ; Ginger Root 

 (Asarum caudatum); Inside-out Flower (Vancouveria parviflora); 

 Vanilla Le^f (Achlys triphylla), Saxifraga mertensiana, and Red 

 wood Sorrel {Oxalis oregana). Certain shrubs form a very low 

 understory and often occur in heavy stands, as Blue Brush 

 (Ceanothus thyrsiflorus); Evergreen Huckleberry (Vaccinium 

 ovatum); and Salal (Gaultheria shallon). 



The Canadian Life Zone is not well defined in the Sierra 

 Nevada and has, as a separate zone, only a shadowy or wavering 

 existence. Its natural place is on the average between 5,000 and 

 7,000 feet (1 ,524 and 2,134 m) where there is a mean annual 

 temperature of 50° to 55°F (10° to 13°C) and an average rainfall 

 of 40 to 50 inches (102 to 127 cm). The most useful indicator 

 species in this life zone are Red Fir {Abies magnified), Jeffrey 

 Pine {Pinus Jeffrey i). Western White Pine {P. monticola), and 

 Lodgepole Pine {P. murrayand). The first three species are, how- 

 ever, often found in the upper part of the Transition Zone, 



59 



