reach a mature height of only one or two feet (0.3 to 0.6 m) in 

 50 or 60 years. These dwarfed trees occur with a few other plant 

 species, some of which are restricted to the White Plains soils 

 (e.g., the Fort Bragg Manz^mt2i, Arc tostaphylos nummularia). 

 However, if Pygmy Cypress or other tree species that occur on 

 these soils break through the hardpan or become established on 

 more normal soils, they will grow to the usual tree-like propor- 

 tions that one expects. In this case, therefore, the dwarfing is 

 induced by the unusual soil characteristics and is not a part of 

 the genetic makeup of the plants that occur in the area. 



North Coastal Forest (Plates 7; 8A, B; Map 4) 



The greatest difference between the Munz and Keck treatment 

 of California plant communities and that presented here is in the 

 interpretation of the North Coastal Forest. Munz and Keck 

 break up this collective plant community into several plant com- 

 munities: the North Coastal Coniferous Forest, Redwood Forest, 

 Douglas Fir Forest, and Mixed Evergreen Forest. Arguments can 

 be offered pro and con the conservative treatment used here, 

 but it is simpler to treat this complex and variable assemblage of 

 woody plants as a single plant community. The North Coastal 

 Forest occurs over much of the North Coast Ranges, in the Sis- 

 kiyou-Klamath mountains, and in the Santa Cruz mountains. It 

 continues northward along the Pacific coast into southern Alaska; 

 patches of forest referable to this plant community occur in the 

 vicinity of Mount Shasta as well, although in this last area most 

 of the typical conifers are absent and the plant species present 

 are those characteristic of Munz and Keek's Mixed Evergreen 

 Forest. 



Over most of its area of distribution, the North Coastal Forest 

 is dominated by one or more species of coniferous trees. These 

 include majestic species such as Coast Redwood {Sequoia semper- 

 virens, Plate 7 A), Douglas Fir (Pseudotsuga menziesii, Plate 7 A), 

 Western Hemlock (Tsuga heterophylld). Lowland Fir {Abies 

 grandis), Sitka Spruce {Picea sitchensis), Canoe or Western Red 

 Cedar {Thuja plicata), and Port Orford Cedar {Chamaecyparis 

 lawsoniana). Also present are the Giant Chinquapin {Chrysolepis 



85 



