Pool: THE VEGETATION OF THE SANDHILLS OF NEBRASKA 193 



cover. He has pointed out very clearly that when the native vege- 

 tation of the Great Plains Area is well understood as to its compo- 

 sition and water requirements, one may conclude rather definitely 

 as to the probable success when various cropping systems are at- 

 tempted upon this land showing one or another of the common 

 plant associations. This paper is of particular ecological interest 

 in connection with the studies of the sandhill vegetation of Ne- 

 braska. Certain comparisons between these regions will be recorded 

 in the following pages. The last papers that deal with sandhill 

 vegetation and related conditions are by myself (53, 54) and are of 

 a more or less popular nature. 



This investigation has been conducted under the direction of 

 Professor C. E. Bessey, and I am pleased to express my apprecia- 

 tion of the aid and kindly counsel which he has so freely given dur- 

 ing the progress of the studies. Professor F. E. Clements, of the 

 University of Minnesota, has offered criticism and suggestions, and 

 I am especially grateful to him for having read the first draft of 

 this paper. I am indebted to Professor G. E. Condra for guidance 

 in the study of the physiography, soil conditions, and drainage of 

 the sandhill region. Thanks are due the Reverend J. M. Bates for 

 aid in the determination of certain sedges. I am also indebted to the 

 Nebraska Conservation and Soil Survey for help that made possible 

 the extension of my studies over a wide territory. I wish further- 

 more to acknowledge my indebtedness to the United States Depart- 

 ment of Agriculture, Bureau of Soils, for the determination of the 

 mineral content of certain soil samples and for mechanical analyses 

 of sandhill soils which will be found among the following pages. 

 Finally I wish to express my appreciation to the United States De- 

 partment of Agriculture for permission to reproduce certain figures 

 from Bulletin No. 213 by Dr. H. L. Shantz, of the Bureau of Plant 

 Industry, and to the office of Alkali and Drought Resistant Plant 

 Breeding Investigations for the determination of the moisture 

 equivalent of certain sandhill soil samples. 



AREA AND POSITION IN THE STATE 



Until a detailed soil survey of the state is completed we can not 

 tell except approximately the total area of our sandhills. Estimates 

 varying from 15,000 to 24,000 square miles have been published by 

 various investigators (Barbour 2, Darton 33, Condra 28, Bessey 



