Phytogeographie Survey of North America, 
Preface. 
he conservation movement in America had its origin a number of years 
ago in the agitation to preserve the forests of the nation from total 
destruction. During the administration of President ROOSEVELT, the movement 
was given national significance by a meeting in Washington of the governors 
of the different states, and other prominent men of affairs, to consider whether 
something could be done to conserve not only the forests, but other natural 
resources, as streams, mineral products and agricultural soil. This meeting 
was followed by several conservation congresses in which matters of national 
importance were given prominence. One of the results of these gatherings_ of 
public-spirited men was an inventory of. our natural resources made by the 
scientific bureaus in Washington, aided by the National Academy of Sciences. 
As a result of this inventory, we know approximately the extent of our forests, 
the amount of coal which we have for future use, and the location of the oil 
and mineral deposits. 
But with the settlement of the continent and the exploitation of its resources, 
such as the drainage of its swamps, the removal of the original forests and 
the construction of irrigation works in arid districts, the original condition of 
the land surface and its vegetation will be changed forever. It is important, 
therefore, for this generation of botanists and scientists to leave in printed form, 
in photographs, in maps and in other illustrations a record of the original 
appearance of the country before the march of civilization has destroyed 
primeval conditions. This from the standpoint of the botanist is an important 
matter, because all future botanic and forestry work must be based on con- 
siderations of what was the character of the native growth. Fully recognizing 
this fact, the writer at the suggestion of the editors of “Die Vegetation der Erde”, 
undertook ten years ago to write a sketch of the Vegetation of North America, 
and this volume is the outcome of the study of American vegetation, begun 
over twenty years ago. 
During this time trips have been made to all the more important phyto- 
geographic regions of North America, excepting the Arctic tundra, and the 
itinerary of such collecting trips included the Bermudas, the Bahamas, the Greater 
Antilles, Mexico, the Pacific coast states, the Rocky Mountains, the prairie 
