PRAIRIE INCLUSIONS IN THE DECIDUOUS FOREST CLIMAX 
Herbert C. Hanson 
(Received for publication November 25, 1921) 
Introduction 
In the deciduous forest of the central states small fragments of prairie 
frequently occur (see fig. i). These vary in area from a few square feet to 
several acres, occurring usually on hillsides exposed to the south, southeast, 
or southwest. Shimek (5, 6, 7) has noted them in northwestern Iowa and 
along the Missouri River; Pammel, MacDonald, and Clark (2) along the 
Missouri River in Iowa; Vestal (8) in Illinois; Pool, Weaver, and Jean (3) 
in southeastern Nebraska, and the writer in the vicinity of Cincinnati, Ohio. 
During the spring and summer of 191 7, near Peru, in southeastern Nebraska, 
the writer studied intensively two small inclusions in relation to the sur- 
rounding forest. The data collected in this study are important in explain- 
ing the occurrence of prairie inclusions. 
General Description of the Region 
From the broad lowlands of the Missouri River in southeastern Nebraska 
arise abruptly densely wooded hills and bluffs, broken by numerous valleys 
and ravines. The forest of this hilly region is of the red oak-hickory type. 
It varies greatly in width, but in the fairly level upland soon gives way to 
the prairie. Pound and Clements (4) and Pool, Weaver, and Jean (3) have 
studied and described this forest in detail. The latter have shown by in- 
strumental and quadrat studies that the succession from grassland is 
through the following stages: shrub, Quercus macrocarpa-Q. acuminata, Q. 
velutma, Q. ruhra-Hicoria ovata, which is dominant in fairly mesophytic 
situations, and the final stage, Tilia americana-Ostrya virginiana, which is 
dominant on the moister slopes and in ravines. 
A striking feature of this hilly forest region is that often on the sides 
and tops of the steep slopes and on the crests of ridges in the midst of the 
dense forest are found prairie areas varying from a few square feet to an 
acre or more. These fragments of prairie are usually found on south, south- 
east, or southwest slopes, directly exposed to the sun and to the wind which 
is prevailingly from the south from April i to October i. The vegetation 
of the fragments is composed of typical prairie plants. The following 
grasses, forming well-defined bunches, are dominant: Andropogon furcatus 
Muhl., Schizachyrium scoparium (Michx.) Nash, Sorghastrum nutans L., 
and AtJieropogon curtipendulus (Michx.) Fourn. Between the bunches are 
found numerous typical prairie herbs and occasionally a few shrubs. 
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