SITK DETKRM I NATION' AND VIF.LD I'UKKCAST ^ 



series it is 'AO feet. In mixed even-aged stands it was found 

 that the range in height of the dominants was never as much as that 

 between maximum and minimum for the same age and site in the 

 three-'class table, and rarely more than that indicated in the six-class 

 table. The determination of site by means of these tables should, 

 however, be based upon averages between the different species of 

 intolerant hardwoods available for measurement. This will not be 

 hard to do. ( )ne hundred per cent pure stands monopolizing any 

 area of uniform site quality large enough to demand separate notice 

 in management plans will never be found, and a mixture of species 

 among the dominants from which an average can be secured will un- 

 doubtedly be available in every case. 



This classification therefore conforms to the Roth plan of 10-foot 

 unit height intervals at 100 years. In addition the curves set a single 

 "standard" for the less tolerant species ("similar growers") by which, 

 since these arc abundant species, the southern upland hardwoods in 

 general may for the time being be classified. Later on the species 

 which dififer from these in the direction of the dominant height growth 

 curves may be similarly provided for by one or more sets of "standard" 

 curves, drawn through 10-foot units at 100 years, and thus become a 

 part of a general classification scheme for the species throughout its 

 range. A basis for comparing sites and growth rates for different 

 species or the same species in different parts of the country will thus 

 be provided. Yield tables for a given species and site in different 

 regions may not always be identical ; if not, means for evaluating those 

 for one region in terms of another will be found, and such comparisons 

 will certainly be of value. 



APPLICATION OF THK TABLKS IN DETERMINING SiTK 



The application of these tables to the determination of site differs 

 somewhat according to the nature of the stand. If the stand is even- 

 aged it is simply a matter of ascertaining its age and the average height 

 of the dominant hardwood trees of a number of species. This can be 

 determined with sufficient accuracy by hypsometer measurements of 

 a very few representative trees. If. as is much more likely to be the 

 case in the Southern Appalachians, the stand is open, uneven-aged, 

 and irregular as to crown height, the determination requires more care. 

 First, some of the "mature" trees, which from their height and crown 

 shape bear evidence of having held a commanding position in the 

 original crown cover, should be measured for total height ; their ages 



