ANOTHER WORD ON SITE 



By Filibert Roth 

 Professor of Forestry, University of Michigan 



In the April number of the Journal Bates has a most stimulating 

 article, "Concerning Site." It is not altogether clear whether the article 

 is simply to discuss site classification or whether its chief function is to 

 "draw fire." If the latter, it is a "winner," and in any case it is refresh- 

 ing to see a real, live interest in a subject which so long has seemed to 

 most of our American foresters as either of no value or else of such 

 difficulty that it must be left to the far future, when all kinds of modern 

 soil studies can be made. . 



The article starts out with the sentence : "The only final criterion of 

 site quality is the current anniial cubic-foot increment of a fully stocked 

 stand of the species under consideration." It adds : "Any other cri- 

 terion of site quality is a compromise or a makeshift, etc." ; also : "In 

 talking about the increment criterion of site quality, the writer is dis- 

 tinctly not discussing makeshifts or temporary expedients, but rather 

 an actual standard of site qualities which because it is exact and con- 

 tains the smallest possible element of human judgment uiav nozv begin 

 to be and remain forever the standard of American foresters." . . . 



Since yield tables, both European and American, claim tiiat the cur- 

 rent growth of a pure, even-aged stand is merely nominal in the first 

 ten years. rai)idly increases, reaches a maximum at 30 to 50 years, and 

 then ra])idly, later on more slowly, declines in its rate, it would seem 

 that the same acre of land will be of low site quality at the start, be of 

 the best quality when the growth is a maximum, and then decline as the 

 stand grows older. 



Bates seems convinced that the yield tables so far prepared are in 

 error on this pciint. On page 386 a small table of figures from a lodge- 

 pole-pinc study is to indicate that the current growth of a stand is a 

 constant, and this is emphasized by a statement regarding hickory, 

 which says : ". . . the increment was essentially the same over wide 

 areas of uniform delta lands, regardless of the age of the stand." 



The table of lodgepole-pine figures is interesting and a part is here 

 repeated. It is inferred that all figures are from a stand 55 years old, 



74!) 



