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bluffs, even where they are thin-soiled and rocky, are characterized 

 by a great variety of species, probably due to the nearness of the 

 bottoms and to the increased atmospheric moisture. Various mixtures 

 of the following species are found on these bluffs : white, black, and 

 bur oaks, white and red elm, walnut, butternut, ash, hickory, sycamore, 

 honey locust, sugar maple, cottonwood, buckeye, coffeetree, and 

 juniper or red cedar. In the vicinity of Rock Island, basswood and 

 cherry begin to form an appreciable part of the stand, and farther 

 north, toward the "driftless area," aspen begins to come in. White 

 pine grows on the bluffs of the Rock, Apple, and Galena rivers. 



Tree growth is rapid on most of the northern Illinois soils, and 

 the stands are generally thrifty and free from extensive insect or 

 fungous injury. Many woodlots are not restocking because grazing 

 prevents young growth from getting a start. In most sections the 

 forest fire problem is fully within the control of the individual owner, 

 who is, unfortunately, not always well informed as to the effect of 

 burning over his woodland. 



Calhoun and Jo Daviess Counties 



The largest proportion of forest land is in the rough, unglaciated 

 areas of Calhoun and Jo Daviess counties. Conditions in these counties 

 are therefore of special interest. 



Calhoun County is a long and narrow strip of land lying between 

 the Mississippi and Illinois rivers. The country rises high above the 

 bottomlands in precipitous cliffs, and is cut up by the many short and 

 steep tributary valleys so that there is little level land. The well- 

 drained fertile soils support on the gentler slopes flourishing apple 

 orchards and farms, and on the steep valley sides and bluffs a forest 

 growth composed of a wide variety, mostly of small trees. Black, red, 

 and white oaks predominate, but on the lower slopes sugar maple, 

 basswood, buckeye, and many other species are represented. 



Jo Daviess County covers the northwest corner of the state, where 

 the highest elevations are. With the rest of the "driftless area," so 

 famous among geologists, it escaped glaciation and presents a rugged 

 surface with soils for the most part of residual origin. The drainage 

 system is well developed, with steep valley sides; and long, irregular 

 mounds or ridges rise above the general level of the rolling uplands. 

 Except for the northeast corner, the original forest was unbroken, 

 but now only about thirteen per cent of the county is wooded. 



In composition, the forest differs somewhat from that of the 

 southern counties. There is more bur oak and cottonwood on the 

 uplands, as well as an increased proportion of walnut, red elm, and 



