CONTENTS 



Spatial Relations 342 



Home Ranges and Territories 343 



Migration 343 



Emigration and Immigration 346 

 Population Composition 346 



Distribution 347 



Social Behavior 348 



19 COMMUNITY ECOLOGY 

 Relations among Species 



The Nature of the Community 351 



The Community, A Superorganism? 351 



The Community, A Continuum? 352 

 Community Variations 352 



Sources of Variation 352 



Nature of Variations 354 



Tendency for Equilibrium 357 

 Community Influence 357 



Community Interrelations 357 



Environmental Influence 358 



Stratification 358 

 Successional Status 359 



Dynamic Equilibrium 359 



Occurrence 360 



Communities and Succession 360 



Terrestrial Succession 362 

 Biogeographical Dynamics 364 



Biogeographical Succession 365 



Extinction and Origin 370 



351 



Historical Biogeography 371 



North American Floras and Land Vertebrates 



Intercontinental Movements 383 

 Distribution Schemes 384 



Faunal Regions 384 



Life Zones 385 



Community Types 387 



Biomes 387 



Biotic Provinces 389 



Dynamic Faunas 390 



Scheme Interrelationships 394 



20 ECOSYSTEM ECOLOGY 



Environment-Community Interrelations 



371 



395 



Energy Cycle 395 

 Fundamental Steps 

 Nonessential Steps 

 Functional Niches 



Food 398 



Quantity and Kinds 

 Preference 398 

 Productivity 399 



Biogeochemical cycles 



395 

 396 

 396 



398 



399 



Generalized cycle 400 



Concluding Statement 



Glossary 



Index 



401 

 403 

 422 



