soil in the interval rerjuired to attain a merch?,ntab!e diameter. Black oak 

 in even-aged stands on upland yellow-gray sandy loam attained such a 

 diameter in 44 years, on upland yellow-gray silt loam in 53 years, on 

 dune sand in 53 years, on upland yellow silt loam in 60 years and on the 

 heavy yellow-gray silt loams of the Illinoisan in G3 years. The influence 

 of soil is more accurately reflected in the height growth than in diameter 

 growth. Thus 55-year old black oak on upland yellow-gray sandy loam 

 has a height of 61 feet, on upland yellow-gray silt loam of 55 feet, on 

 upland yellow silt loam of 55 feet, on dune sand of 50 feet, and on the 

 Illinoisan yellow-gray silt loam of but 40 feet. Since height and diameter 

 determine the cubic contents, the ratings of the productiveness of soils 

 for any given species is best expressed by cubic contents. Such a rating 

 is shown in Table 3. pp. 72-80, in which E signifies even-aged stand, and 

 A equals ali-aged stand. 



