Site index is an expression of forest site qual- 

 ity based on the height of the dominant stand 

 at an arbitrarily chosen age. Site is further de- 

 fined as an area, considered as to its ecological 

 factors with reference to capacity to produce 

 forest or other vegetation; the combination of 

 biotic, climatic, and soil conditions of an area. 9 



For our purposes we will consider site index 

 as the total height attainable by the average 

 dominant and codominant trees in stands at the 

 age of fifty years. 10 



9 Society of American Foresters. Forestry Terminol- 

 ogy. Third Edition. 1958. 



10 Gevorkiantz, S. R. 1957. Site Index Curves for 

 White Pine in Lake States. Technical note 483, Lake 

 States Forest Experiment Station, St. Paul, Minn. 



The measurements required for the determi- 

 nation of site index can be made by one man, but 

 better results are usually achieved by two to 

 four man crews. 



Equipment required for the job includes an 

 increment borer for determination of age of the 

 tree, a hypsometer for measuring tree height, 

 a one-chain tape, and site index curves for the 

 desired tree species. The tape will not be neces- 

 sary if a range finder is on the hypsometer. 



PROCEDURE " 



11 Avery, T. E. and Herrick. A. M. Field Projects and 

 Classroom Exercises in Basic Forest Measurements. Uni- 

 versity of Georgia Press-Athens. 1963. 



FIGURE 1. — Determination of site index 



Form 1 



Property ownership 

 Date 



Species_ 



County 



Person performing work 



Tree no. 



Crown class ' 



Total height 



Age at dbh 



Total age 



1 











2 











3 











4 











5 











6 











7 











8 











9 











10 











11 











12 













Totals 





XXX 







Means 





XXX 





1. Dominant or 

 codominant 



Site index (from cur\ 



es): 







30 



