DeMars, Donald J.; Herman, Francis R.; Bell, John F. 1970. Preliminary site index curves for noble fir from stem analysis data. Res. Note PNW-119. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 9 p.
Preliminary polymorphic site index curves were developed using stemanalysis data from 54 plot locations in Oregon and Washington. Site indexreference age is 100 years at breast height, and total height is measuredfrom average ground level. A family of 11 curves was obtained from fourpolymorphic curves by interpolation and proportional methods. The curveswere extended from 250 to 350 years of age to provide site index valuesfor these older age classes.
The curves were based on tallest dominants only; therefore, thetallest dominant should be used when estimating the site index of aparticular area. Curves based on additional stem analyses of noble firwill be produced in the future.