of grove-like aspect, bordering the streams and thinning rapidly as the 

 prairie was approached. Toward the margin the forest floor was car- 

 peted with a dense growth of seedling sprouts growing between the scat- 

 tered old trees. These sprouts were annually killed by fires, the occa- 

 sional survivors developing into gnarled, fire-scarred outposts of the 

 forest margin. The average vield for this oak-hickory type was probably 

 3,000 B. F. per acre. 



One other extensive and three limited types are worthy of mention. 

 Throughout the northern part of the state are extensive areas of sandy 

 soils. Whether on the flood-plain of a large river or as an interior sand 

 hill, the type of vegetation reflects the lack of soil moisture. Character- 

 istically desert forms, such as cactus (prickly pear) may be found. Under 

 certain conditions the vegetation assumed the character of a forest. Scrub 

 oak is one of the commoner species but, with increase in water content 

 of the soil, black oak and hickory occur, and on the best sites white oak 

 grows. Jack pine grows with the scrub oak in the sand area south of 

 Lake Michigan. The pioneers found much of this sand land an unfor- 

 ested waste ; and where forests prevailed the average yield was probably 

 1,500 B. F. per acre. 



Now limited to less than a dozen small areas in Lake and ]\IcHenry 

 counties, though probably in recent times in many other sections, are the 

 tamarack swamps so common to Wisconsin and regions to the north. 

 These stands occupy parts of swamps, and the trees are generally small. 



In two localities in the southern part of the state may be found stands 

 of shortleaf pine. These occupy very exposed slopes on bluffs, and the 

 trees scarcely grow to sawlog size. 



The original forest also held a few groves of white pine in addition 

 to scattered specimens. The southern limit of the species for this region 

 was represented by a grove of two acres on the west bluff of Spoon River 

 about one mile south of Dahinda, Knox county. North of the Illinois 

 River, an occasional tree grew on the stream bluffs ; and there is still a 

 healthy stand of nearly pure pine about eight miles west of Oregon, Ogle 

 county. 



Compared with the United States as a whole, Illinois had almost ex- 

 actly the average relationship between forested and non-forested area. 

 The estimated area originally forested for the United States was 43.3 per 

 cent of the land area, that of Illinois 42.58 per cent. Comparison of 

 average B. F. yields for the areas actually timbered shows that the United 

 States had an estimated average of 6,326 B. F. per acre against 4,281 

 B. F. per acre for forested areas of Illinois. The lower yield per acre in 

 Illinois forests is due to their predominantly hardwood character — hard- 

 woods averaging less than half the yield of conifers under similar con- 

 ditions. 



Thus the original forests of Illinois are estimated to have contained 

 65,385,884,000 B. F. or 16,346,471,000 cubic feet of lumber. Based upon 

 the present average wood requirements per capita for Illinois, this forest 

 contained a quantity of lumber sufficient to supply all the wood needed 



