70 



{'■i) That the difference in the period required to attain a merchant- 

 able size for the same species growing on different soil types is not so 

 marked is shown by the following tabulation. 



Species 



Ash 



Cottonwood. . 



Elm 



Hickory 



Hard maple . . 

 Soft maple. . . 



Pin oak 



Red oak 



Black oak ... 



Post oak 



White oak. . . 



Tulip poplar. 

 Black walnut 



Soil type 



Bottomland deep gray silt loam 



Bottomland drab clay 



Upland yellow fine sandy silt loam 



Upland yellow-gray silt loam 



Bottomland gray fine sandy loam 



Bottomland river wash 



Upland brown prairie loam 



Upland yellow fine sandy silt loam 



Bottomland drab clay 



Bottomland gray fine sandy loam 



Bottomland deep gray silt loam 



Upland yellow silt loam 



Upland yellow fine sandy silt loam 



Upland yellow-gray silt loam 



Upland yellow fine sandy silt loam 



Bottomland yellow-gray silt loam 



Bottomland gray fine sandy loam 



Bottomland drab clay 



Bottomland drab clay 



Bottomland deep gray silt loam 



Upland yellow fine sandy silt loam. 



Upland yellow silt loam 



Upland yellow-gray silt loam 



Upland red-brown fine sandy silt loam 



Upland yellow-gray sandy loam 



Upland yellow-gray silt loam 



Upland red-brown fine sandy silt loam 



Upland sand 



Upland yellow silt loam 



Upland ininoisan yellow-gray silt loam.... 

 Upland light gray silt loam on tight clay. 



Upland yellow-gray silt loam 



Bottomland yellow-gray silt loam on clay.. 



Upland yellow-gray sandy loam 



Upland yellow silt loam 



Upland yellow-gray silt loam 



Upland yellow fine sandy silt loam 



Upland yellow silt loam 



Upland yellow fine sandy silt loam 



Prairie brown silt loam 



Prairie black clay loam 



Intervals required 

 to produce 10- 

 inch trees 



Even-aged i All-aged 



G2 

 61 

 101 

 85 

 72 

 86 

 93 

 76 

 93 



72 



57 



66 



74 

 62 

 96 

 97 

 42 

 37 

 36 



For the species studied, the difference in time required to attain a 

 merchantable size is greatest for the elm and this difference is but -10 

 years. In the case of the white and the black oaks, where the studies 

 have been the more complete, there is surprisingly little difference due to 



