VIII 



CONTENTS. 



PAGE. 



IV. Climax Formations of Western 



North America — Continued. 



the petran chaparral — Continued. 



Societies. 



Vernal societies 187 



Estival societies 187 



Serotinal societies 187 



THE SL'BCLIMAX CHAPARRAL. 



Rhus-Quercus Associes. 



Nature 187 



Extent and contacts 188 



Groupings 189 



Relations of the dominants 189 



Societies. 



THE COASTAL CHAPARRAL. 



Adenostoma-Ceanothus Association. 



Nature and extent 190 



Groupings 191 



Factor and serai relations 192 



Societies. 



Prevernal societies 193 



Vernal societies 193 



Estival societies 193 



THE WOODLAND CLIMAX. 



Pinus-Juniperus Formation. 



Nature 193 



Range and extent 194 



Unity of the formation 195 



Structure of the formation 196 



Contacts 197 



THE PINON-CEDAR WOODLAND. 



Pinus-Juniperus Association. 



Nature and extent 197 



Societies. 

 Shade societies 199 



THE OAK-CEDAR WOODLAND. 



Quercus-Juniperus Association. 



Nature and extent 200 



Factor relations 201 



Societies. 



Shade societies 202 



THE PINE-OAK WOODLAND. 



Pinus-Quercus Association. 

 Nature and extent 202 



THE MONTANE FOREST CLIMAX. 



Pinus-Pseudotsuga Formation. 



Nature 205 



Extent 205 



Unity of the formation 205 



Relationship and contacts 206 



Associations 207 



PAGE. 



IV. Climax Formations of Western 

 North America — Continued. 



THE PETRAN MONTANE FOREST. 



Pinus-Pseudotsuga Association. 



Extent 207 



Groupings 208 



Factor relations 209 



Serai relations 209 



Societies and Clans. 



THE SIERRAN MONTANE FOREST. 



Pinus Association. 



Extent 211 



Groupings 212 



Factor and serai relations 212 



Societies. 



Shrubs 213 



Herbs 214 



THE COAST FOREST CLIMAX. 



Thuja-Tsuga Formation. 



Nature 214 



Extent 214 



Unity 215 



Relationship and contacts 215 



Associations 216 



THE CEDAR-HEMLOCK FOREST. 



Thuja-Tsuga Association. 



Nature and extent 217 



Groupings 217 



Factor and serai relations 218 



Societies. 



Shrubs 219 



Herbs 219 



THE LARCH-PINE FOREST. 



Larix-Pinus Association. 



Nature and extent 219 



Groupings 220 



Factor and serai relations 220 



Societies. 



THE SUBALPINE FOREST CLIMAX. 



Picea-Abies Formation. 



Nature 222 



Extent 222 



Unity 222 



Relationship and contacts 223 



Associations 224 



THE PETRAN SUBALPINE FOREST. 



Picea-Abies Association. 



Extent 224 



Groupings 225 



Factor and serai relations 225 



Societies. 



