FOREST PLANTING IN ILLINOIS. 



INTRODUCTION. 



During a recent field season the Forest Service carried on in 

 Illinois an extensive study of forest plantations, to determine the 

 kinds of trees best adapted to planting in the prairie sections. 

 Illinois has an area of approximately 56,000 square miles. The field 

 work covered about two-thirds of this area, and was confined chiefly 

 to the central and northern parts of the State, or north of a line 

 drawn through Greene and Coles counties. South of this the prairie 

 gives way to natural forest land, and though much of it is cleared 

 there has been little forest planting. The results of the study con- 

 tained in this circular, however, are of general application throughout 

 the State, and also to similar situations in Indiana, Missouri, and 

 Iowa. 



THE REGION. 



Illinois is comparatively level, and contains much true prairie land. 

 This occupies, in general, the central part of the State. In the north- 

 ern and southern portions the country becomes more rolling. 



All variations of soil occur, from deep, black prairie loam to pure 

 sand. Since nearly all of Illinois was once subjected to glacial action, 

 the changes in soil are frequent and often abrupt. 



The climate of Illinois is less humid than that of the Atlantic 

 coast, but much more humid than that of the plains. There is a 

 marked increase in precipitation from north to south. This increase, 

 together with the average annual precipitation for each region, is 

 shown in Table 1, compiled from records of the Weather Bureau. 



Table 1. — Annual precipitation in Illinois. 



District. 



Number 

 of sta- 

 tions. 



Length 

 of record. 



Precipi- 

 tation. 





14 

 11 

 9 



Years. 

 20-44 

 16-32 

 17-33 



Inches. 

 34.58 





37.52 





41.73 







On the whole, both climatic and soil conditions are favorable to 

 tree growth, This is well illustrated by the fact that there are over 

 100 native tree species, and that a large number of foreign species 

 which have been introduced are in a thriving condition. 



[Cir. 81] 



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