chrysophylla), Tanbark Oak (Lithocarpus densiflord), and Bigleaf 

 Maple {Acer macrophyllum), which are hardwood trees associated 

 with the conifers. Understory species consist of small trees or 

 shrubs such as Vine Maple (Acer circinatum, Plate 8B), Evergreen 

 or California Huckleberry (Vaccinium ovatum), Salal {Gaultheria 

 shailon, Plate 7D), California Rose Bay (Rhododendron macro- 

 phyllum), Thimble Berry (Rubus parviflorus), Sword Fern (Poly- 

 stichum munitum), and Redwood Sorrel (Oxalis oregana). 



Climatically, the area occupied by the North Coastal Forest is 

 variable. Average rainfall varies from over 100 inches (254 cm) 

 in redwood areas to as low as 25 inches (64 cm) in inland areas 

 occupied by forests of Douglas Fir or the phase of the North 

 Coastal Forest that Munz and Keck designated as the Mixed Ever- 

 green Forest. Where this plant community occurs on the immedi- 

 ate coast it is in a cool area dominated by coastal fog during much 

 of the summer; inland, summer temperatures become increasingly 

 higher and the winter temperatures increasingly lower. These 

 gradients in moisture and rainfall are reflected in differences in 

 the species composition of the North Coastal Forest throughout 

 its area. In the wetter portions of its range, this forest is domi- 

 nated by the Coast Redwood, Sitka Spruce, Western Hemlock, 

 Canoe Cedar, or Port Orford Cedar. In somewhat drier areas, 

 Douglas Fir is the dominant tree species. In even drier, warmer 

 areas — usually on the inland slopes of the North Coast Range - 

 conifers give way to various broad-leaved trees such as Kellogg 

 Oak (Quercus kelloggii). Canyon Oak (Q. chrysolepis), Tan Oak 

 (Lithocarpus densiflord), Madrone (Arbutus menziesii), California 

 Bay (Umbellularia califomica), California Hazelnut (Corylus 

 cornuta var. califomica), Mountain Dogwood (Comus nuttallii). 

 and various species of the shrubby California lilac (such as Ceano- 

 thusparryi and C thyrsiflorus). As the average rainfall decreases 

 even more, the North Coastal Forest may be replaced by Valley 

 and Foothill Woodland, Valley Grassland, or in some areas, 

 Chaparral. 



Because of its floristic complexity, it is difficult to make 

 many meaningful generalizations about the North Coastal Forest. 

 However, a few species deserve special comment. Perhaps the 

 best known phase of the North Coastal Forest is that segment of 



86 



