Relationships between breast-height and whole-stem growth indices for red spruce on Whiteface Mountain, New York

This paper describes relationships between tree growth indices based on ring width measurements at 1.4 m aboveground and indices derived from whole-stem analysis for red spruce (Picearubens Sarg.) in a high-elevation spruce-fir forest on Whiteface Mountain, New York. Coefficients of determination for linear regressions between mean, standardized chronologies for breast-height ring width versus whole-stem ring width and basal area increment versus annual volume increment are 0.89 and 0.93, respectively. However, substantial variability is apparent in breast-height versus whole-stem relationships for individual trees, particularly for unstandardized growth indices. Also, relationships between unstandardized growth indices exhibit temporal instability associated with individual tree maturation and stand dynamics. Nonetheless, strong relationships between mean standardized chronologies of breast-height and whole-stem growth indices validate the use of breast-height growth indices to represent year-to-year variation in mean growth performance of red spruce. A volume-equation-based procedure is described that provides better dendrochronological estimates of annual volume increment than estimates based on basal area increment alone.