276 ILLINOIS ACADEMY OP SCIENCE 



tured and only six three-inch trees were found in the 8 

 acres of strip, those being in ravines. The trees were very 

 short boled, most of them making not over one 12 foot log. 

 Some cutting had been done for fence posts and the 

 diameter growth of such open grown trees had been rapid, 

 some trees having grown 2 inches in radius in ten years. 

 Trees 13 inches in diameter on the stump were from 50 to 

 55 years old. 



Per cent of species 



White oak 58.7% 



Bur oak 12.8% 



Shagbark Hickory 13.7% 



Others 14.8% 



Total .... 100.0% 



Number of trees per acre 46 



Average board feet per acre 1881 



Tract E. Ravine Forest — Illinois river (Cedar Creek. 



Peru Township, Sec. 31). 



Ravine type. This is about the only place where maple 

 is found in abundance. This strip included the bottom 

 of a small ravine and the side of the ravine, running out to 

 oak hickory forest at the top of the ridge. Had been pas- 

 tured and trees are larger than C, hence estimate runs 

 higher. On the sides of the ravine are good conditions for 

 reproduction if stock were excluded as acorns are lying on 

 exposed mineral soil and only need a slight covering to 

 germinate. As shown by the tally sheet, the number of 

 species is quite large for a small area but red oak and rock 

 maple are the dominant species. Such ravines should be 

 kept in timber and grazing prohibited. It is such ravines 

 that show up as the forested areas on the topographic 

 sheets of the Geological survey. 



Average number of trees per acre 115 



Volume per acre 3,855 board feet. 



Per cent of species 



Red oak 20.8% 



Hard maple 30.6% 



Others 49.6% 



Total .... 100.0% 



