76 



NATURALIST'S GUIDE TO THE AMERICAS 



IV. Temperate Rain Forest 

 V. Sub-tropical Rain Forest 

 VI. Poplar Savanna 

 VII. Oak Savanna 



VIII. Rocky Mountain Forest 

 Margin 

 A. Chaparral 



B. Woodland 

 IX. California region of various 

 vegetation with Summer 

 drouth and Winter Rain 



A. Chaparral 



B. Woodland 



C. Coastal sagebrush or 



"chaparral" 



D. Bunch-grass plains in 



valleys (cultivated) 

 X. Grassland 



A. Prairie 



B. Steppe (Brush — grass- 



land in part) 



XI. Bush-Steppe 



1. Semi-desert 



west 



2. Semi-desert 



west 

 XII. Temperate Desert 



North- 

 South- 



XIII. Subtropical Desert 



A. California Microphyll 



Desert 



B. Succulent Desert 



XIV. Thorn Savanna 



"Hammock" Country, 



Florida 

 Very rare frost, south tip 



of Florida 

 Mixture of poplars and 



tall grasses 

 Mixture of oaks and tall 



grasses 



Brush, as dwarf oak 

 (Quercus undulatus) 

 and Mountain mahog- 

 any {Sercocarpus par- 

 vifolius) 



Pinj'ons and junipers 



Brush, as Manzanita and 

 Buck brush 



Evergreen oaks, jun- 

 ipers, etc. 



"Old Man" (Artemisia 

 californica) and Salvia 



Tall grass in bunches 



Largely included in 

 Savanna VI and VII 



Grasses in open sod. 

 Bare ground between 

 plants, or rather short 

 grasses forming sod 



Mixed grass and sage- 

 brush 



Mixed Grass and desert 

 shrub 



Sagebrush-Atriplex- 

 rabbit brush 



Creosote bush and Sand- 

 bur 

 Cacti, mesquite, etc. 

 Thorn bushes and grass 



Sabalian Zone 

 Tropical Zone 



Transition and Al- 

 leghanian 



Alleghanian, Car- 

 olinian and 

 Austroriparian 



Arid Transition 



Upper Sonoran 



Arid Transition 



Upper Sonoran 



Upper Sonoran 



Upper and Lower 

 Sonoran 



Arid Transition 

 and LTpper Son- 

 oran 



Upper Sonoran 

 Upper Sonoran 

 Upper Sonoran 



Lower Sonoran 



Lower Sonoran 

 Lower Sonoran 



The maps of Southern North America 

 and Northern South America are the 

 results of the circulation of three pre- 

 liminary maps. The earlier maps were 

 criticized by T. Barbour, L. Griscom, 

 G. K. Noble, A. G. Ruthven and others. 

 A much larger scale map was then 

 planned with the aid of Dr. W. H. Os- 

 good, drawn and circulated. Most of 

 the contributors of tropical accounts 

 made important suggestions and Mr. 

 E. P. Killip of the National Museum 

 added his knowledge of several countries. 



Florida may be used to illustrate diffi- 

 culties in mapping the vegetation of 

 areas. It is covered largely by long- 



leaf pine, and is commonly mapped as 

 coniferous forest. Detailed study 

 shows, however, that on well-developed 

 soils in stable physiographic situations 

 such as the highest terraces of flood 

 plains, other types occur which indicate 

 future dominants. Thus Professor Wat- 

 son shows northwestern Florida to be 

 deciduous forest, • much of central 

 Florida to be temperate rainforest 

 (evergreen), southeastern Florida to 

 be tropical rainforest, and the remain- 

 ing parts are represented according 

 to present dominants because neither 

 the knowledge nor conditions make 

 possible prediction of the coming type. 



