THE PROBLEMS OF ECOLOGY 



BY BENJAMIN LINCOLN ROBINSON 



[Benjamin Lincoln Robinson, Asa Gray Professor of Systematic Botany, Curator 

 of Gray Herbarium, Harvard University, b. November 8, 1864, Bloomington, 

 Illinois. A.B. Harvard University, 1887; Ph.D. Strassburg University, 1889. 

 Fellow of the American Academy of Arts and Sciences; Fellow of the American 

 Association for the Advancement of Science; Member of the Botanical Society 

 of America; Corresponding member of the Botanical Society of Brandenburg. 

 Author of A Flora of the Galapagos Islands; and numerous papers on sys- 

 tematic botany. Editor of Synoptical Flora of North America; Rhodora, Journal 

 of the New England Botanical Club.] 



ONE hundred years ago our country more than doubled its ex- 

 tent. At the anniversary of this great event, one of the most mo- 

 mentous in our national history, it is fitting that its widespread 

 effects should be considered not merely in relation to the growth and 

 material prosperity of our country, but to all phases of the intel- 

 lectual and scientific development of the nation. Our subject this 

 afternoon is certain problems regarding plant life, problems which 

 have become practical, important, and even vital to the interests of 

 the American people, largely through the very territorial accession 

 which we are now commemorating. While the Louisiana Purchase 

 doubled the area of the United States, it increased in a far higher 

 degree the physical and climatic diversity of the country. The 

 newly acquired territory contained wider prairies, higher moun- 

 tains, greater forests, deeper gorges, and more arid plains than any 

 east of the Mississippi. It was a region of extremes of altitude, tem- 

 perature, and precipitation. Its successful exploration, settlement, 

 and agricultural development presented to our government and 

 national energy problems as intricate in their solution as they were 

 vast in magnitude. 



Furthermore, the subsequent annexation of Texas and Cali- 

 fornia was a logical sequence of the Louisiana Purchase, for it would 

 scarcely have occurred had Louisiana remained in foreign posses- 

 sion. When the great Southwestern and Pacific States, with their 

 still more varied climate and floras, are thus brought also into con- 

 sideration, it will be seen that the Louisiana Purchase has directly 

 or indirectly increased by many times the extent and importance 

 of the botanical problems of our nation. 



It is a matter of common experience that one of the best indica- 

 tions of the value of wild land is furnished by its native vegetation; 

 and it is of interest to notice how early in the exploration of the 

 Louisiana Purchase this fact was realized. The management of this 

 great and beautiful exposition has named this very day in honor of 



