AN ECOLOGICAL STUDY OF A PRAIRIE PROVINCE IN 

 CENTRAL IOWA. 



BY ADA HAYDEN. 



(Abstract.) 



This virgin prairie area is mostly of the kame hill, saucer type. 

 One portion of the territory is probably the pre-Wisconsin bed of the 

 Des Moines river whose course was changed by the ice sheet. The 

 region examined in detail is one mile in radius and bordered by a 

 woodland adjacent to Skunk river. 



The purpose of the study was (1) to determine the identity of the 

 plants and their locations, (2) to examine environmental factors with 

 a view to accounting for their relative influence in the grouping of 

 the plants. Factors obviously common to the various associations were 

 not considered. Those factors concerning which data were taken are: 

 Topography, drainage, soil type, weather, water content of earth at 

 highland and lowland stations, comparative temperature studies at the 

 same stations including the maximum and minimum temperatures of 

 earth and air, and a comparison of surface, sub-surface and sub-soil 

 earth temperatures with those of the air at these stations. 



In summarizing results, an analysis of the floral distribution of the 

 prairie province showed the following grouping: 



I. Upland prairie 



Stipa — Bouteloua formation. 

 Consocies Bouteloua 

 Consocies Stipa 



II. Meadow or Wet Prairie 



Panicum — Agrostis formation 

 Consocies Phlox maculata 

 Consocies Agrostis, Steironema, Lythrum 

 Consocies Panicum, Fragraria, Senecio 



