294 THE STUDY OF PLANT COMMUNITIES * Chapter X 



Ohio. Because here it includes somewhat different combinations 

 of species, some of which are dominant, the community is re- 

 garded by some as a separate association. The predominating tall 

 grasses, as well as other basic similarities, make it reasonable to 



FIG. 157. Mixed grass community in Arizona in which grama grasses pre- 

 dominate.— U. S. Forest Service. 



others to consider the prairie peninsula as a f aciation of Tali Grass 

 Prairie to which it bears a postclimax relationship. The soils with- 

 in the peninsula are prairie soils although the climate is now that 

 of forest climax. The community may, therefore, be regarded as 

 preclimax to the forest, maintained by edaphic conditions. 



Mixed Grass Prairie.— Although the mixed grasses occupy an 

 area between that of the tall grasses and short grasses and the dom- 



