CONTENTS xvii 



Page 

 CHAPTER XII 



Life Forms and Synecological Units 287 



Raunkiaer's System 288 



Adaptability of Life Forms 297 



Life Forms in Plant Geography 298 



Ecological Significance of Life Forms 299 



Synecological Units 301 



Synusia 302 



Formation 302 



PART IV. SYNGENETICS 



CHAPTER XIII 



The Development of Communities 305 



Historical 305 



Early Colonization 306 



Development of Vegetation and Soil Formation 310 



Alpine Regions 311 



Humid Regions of Europe 313 



1. Causative (Dynamogenetic) Value of Species (Constructiveness) . . 315 



Expression of Constructiveness 316 



Constructiveness of Species in the Alpine Gravel Associations . .319 



Determination of the Constructiveness of Species 320 



2. Syngenetic Units 320 



Stage 320 



Phase 321 



Sere 321 



Complete Seres. Partial Seres 322 



Climax 322 



Permanent Communities 322 



Climax Complex. Climax Area 323 



Progressive and Retrogressive, Primary and Secondary Succes- 

 sions 325 



Climax Fluctuations 325 



Practical Significance of Syn genetics 327 



3. Methods of Syngenetic Research 328 



Presentation of Social Development 332 



Curve Diagrams 333 



Block Diagrams 334 



4. Syngenetic Classification 334 



5. History (Synchronology) of Vegetation 336 



Pollen Analysis 337 



Pollen Statistics. Pollen Diagrams 338 



Pollen Analysis and the Development of Vegetation 338 



