NATURAL AREAS AND REGIONS 



519 



Contains a great deal of information 

 of conditions as they occurred at that 

 time. Discusses geology, meteorology, 

 mammals, birds, reptiles, fishes, mol- 

 lusks, insects and plants. 

 Kansas University Quarterly, Volumes 

 I-X. 



Contain many valuable papers on 

 Kansas animals and plants. State 

 lists of many groups are given and 

 many groups are monographed. Kan- 

 sas Univ. Geol. Swv. of Kans.. Vols. 

 I-IX. 



Of geological interest. 

 Inman, Henry. The Old Santa Fe Trail. 

 Crane & Co., Topeka, 1899. Also, 

 The Great Salt Lake Trail. Crane & 

 Co., Topeka, 1899. 



Of historical interest. Descriptions 

 are given of many local areas. The 

 habits and distribution of many of 

 the early animals and plants are dis- 

 cussed. 



3. NEBRASKA 

 BY ROBEKT H. WOLCOTI 



I. GENERAL CONDITIONS 



The altitude of Nebraska increases 

 from 810 ft. in the southeast corner to 

 5360 ft. at the Wyoming line in Banner 

 County. The state as a whole may be 

 likened to a great inclined plane, rising 

 at the rate of 6 ft. per mile for the first 

 hundred miles, and faster and faster as 

 one proceeds westward until for the last 

 50 mi. the rise is 18 to 20 ft. to the mile. 

 The mean elevation is 3085 ft. 



The soils and physiographic features 

 are varied. Three soil regions have been 

 recognized: (1) The loess region, cor- 

 responding to the rolling prairies of the 

 eastern portion, includes loess plains and 

 hills, with various types of silt loams, 

 drift hills with drift, clay and sand, 

 alluvial plains, bluffs, canyons, very 

 little stony land, and very few rock 

 outcrops. (2) The sand-hill region, in 

 the central portion, is mostly dune sand 

 with sandy loams in the valleys, which 

 may be dry or wet, with hay fiats, 

 marshes or lakes. (3) The high plains 

 in the western portion, the soils of which 

 vary from those of fine texture to those 

 of rough stony land, with frequent 

 rock outcroppings, includes broad pla- 



teaus, deep and steep-walled canyons, 

 bold escarpments, buttes, and here and 

 there areas of "bad lands." 



All of the drainage of the state is into 

 the Missouri River, little directly but 

 through tributaries, such as the Ni- 

 obrara, the Platte, the two Nemahas, 

 and the Blue and Republican by way 01 

 the Kansas River. 



The climate is a typical inland climate, 

 with hot summers, mild dry winters, and 

 sudden and severe changes. The mean 

 annual temperature varies from over 

 52 in the southeast to less than 45 

 in the northwest. The nights in summer 

 are generally cool especially in the more 

 elevated western portion. The mean 

 annual rainfall decreases from over 33 

 in. in the southeast to less than 15 in. 

 in the west ; moreover, run-off and evapo- 

 ration both increase greatly as one goes 

 westward. Seven-tenths of the rainfall 

 comes in the growing season, from April 

 to August, and during the middle of this 

 period the climate of southeastern 

 Nebraska can almost be called humid. 

 The mean annual humidity varies from 

 about 67 to 69%. The mean wind 

 velocity is about 10 mi. per hour; being 

 somewhat greater in the west than in 

 the east. 



Five biotic regions may be dis- 

 tinguished: 



1. The Missouri-river bluff region. 

 Includes the bottomlands and wooded 

 bluffs of the Missouri river and the lower 

 portions of its tributaries. Charac- 

 terized by broadleaf forest and thicket 

 communities. Conspicuous habitats: 

 the rivers, with their shifting sand-bars ; 

 the flood-plain thickets of willow and 

 young cottonwoods and the tall bottom- 

 land timber in which cottonwoods are 

 prominent; cut-off ponds, marshes, and 

 swamps; the cool wooded ravines with 

 springs and clear, rapid brooks; the 

 bluffs with more open woodlands in 

 which are oaks, ash, walnut, hickories, 

 linden, and other species of deciduous 

 trees; and steep loess banks, the result 

 of erosion; together with cleared areas 

 and cultivated fields. 



2. The prairie region (tall grass 



