116 



total, based on actual mapped areas supplemented by crop report data, 

 falls to 86.8 per cent of the census figures. If the original forested area 

 of the state was 15,588,965 acres, this indicates that 82 per cent of the 

 forest lands has been actually cleared and is either under crops, or pas- 

 ture, or is classed as waste or eroded land, and has ceased to be forest 

 or woodland. 



The changes wrought in this remaining one sixth of the state's wood- 

 lands by lumbering, fire, and grazing have steadily reduced the stand 

 of timber in both volume per acre and number of trees, and if contin- 

 ued unchecked must finally result in an almost complete ruin of this resid- 

 ual area for forest production by natural processes. 



Classification of Timber by Regions 



The wooded regions of Illinois can be divided, first, into bottomland 

 and upland, with a further classification of each of these based on the 

 prevailing soils and species. The regional classes might be arranged 

 for the state as follows : 



I. BOTTOMLAND 



a. Southern cypress. — This extends from Wabash county south 

 along the Wabash, Ohio, and Mississippi bottoms to McClure, in Alex- 

 ander county, and is found also in the Cache River bottoms. Mixed with 

 the cypress are such species as sweet gum, silver maple, elm, willow, 

 ash, Cottonwood, and Carolina poplar. In the Mississippi bottoms and 

 in the Cache River bottoms, in addition to these species is found tupelo 

 gum. 



b. Mixed hardwood. — This extends from the northern range of 

 cypress along the flood-plains of the principal rivers, Mississippi, Illinois, 

 Kaskaskia, Wabash, and the lower reaches of the Little Wabash and 

 the Embarras. It is characterized by a great diversity of species and 

 shows the best growth rates and yields of any type in the state. It is 

 composed of such trees as the gums, sycamore, ash, hickory, pecan, 

 elm, Cottonwood, silver maple, and pin, swamp-white, burr, white. 

 Schneck's and overcup oaks, in the south; with white, swamp-white, 

 burr, pin, and shingle oaks, elm, hickory, ash, soft maple, river birch, 

 hackberry, sycamore, and cottonwood in the central and northern sec- 

 tions of the state. 



c. Gray clay bottoms of the Big Muddy, Saline, upper Little 

 Wabash and upper Embarras. Pin, shingle, swamp-white, white, and 

 post oaks and ash, elm, hickory, and sweet gum are typical trees. 



