CROP REGIONS OF OHIO 65 



to a full stop. However, we can still see in Ohio the advances of 

 the deciduous forest into regions held by northern evergreens, as 

 for example, the capture of the arbor-vitae bogs by deciduous 

 plants. This movement has been hastened by agricultural activi- 

 ties. The bogs existed only as biological islands. Their destruction 

 means extermination, since the conditions which led to their pres- 

 ei'vation are rapidly passing. 



Ohio has been divided into four vegetation regions by Selby 

 (1899). This had the approval of Dachnowski (1912) p. 203. 

 These four divisions are: 1. The Lake Region; 2. The Western 

 Plain or Calcareous Region ; 3. The Scioto Valley Region ; 4. The 

 Appalachian Region. This static classification has for its chief con- 

 venience the fact that it divides the state into regions of approxi- 

 mately equal size. It has on that account been followed by the 

 United States Weather Service. As a matter of fact it is not very 

 closely related to the biotic centers which traverse Ohio. Following 

 the physiographic divisions already made in this paper, we have the 

 Allegheny Plateau and the Erie Plain. The plateau is occupied by 

 the deciduous forest, which has its center in the Ohio and Wabash 

 valleys, except as the plateau is held by plants of the two evergreen 

 centers. Pinus strobus, from the northern center and P. Virginiana 

 and P. rigida from the southeastern center are both present in the 

 eastern part of the state. The northern evergreen center is better 

 represented than the southern evergreen center. Then there are 

 on the Erie Plain and in a few scattered spots south of the plain, 

 typical prairie plants. The four vegetation centers represented in 

 Ohio are : the deciduous center, the two evergreen centers, and the 

 prairie center. 



The deciduous center, the most important one in Ohio, is rep- 

 resented by such trees as Fagus Americana, Acer Saccharum, 

 which are the principal elements of the climax beech-maple forest; 

 Castanea dentata, Quercus alba, and Liriodendron tulipifera- 

 There are many other trees and shrubs and a large number of her- 

 baceous plants. Trees from the northern evergreen center are 

 Pinus strobus, Tsuga canadensis. Thuja occidentalism Taxus cana- 

 densis, and Larix laricina. The firs and spruces are missing, but 

 the flora is enriched by many northern shrubs and herbs. These 

 are on the edges of their range in northern and northeastern Ohio. 

 The northern species gain their entrance, or rather have not been 

 driven out, through the hills of the eastern section of the state and 



