A local basal area adjustment for crown width prediction
|Authors:||Don C. Bragg|
|Station:||Southern Research Station|
|Source:||Northern Journal of Applied Forestry. 18(1): 22-28.|
Nonlinear crown width regressive equations were developed for 24 species common to the upper Lake States of Michigan, Minnesota, and Wisconsin. Of the species surveyed, 15 produced statistically significant (P < 0.05) local basal area effect coefficients showing a reduction in crown width increasing stand density. No relation between shade tolerance and crown width was apparent, indicating the species-dependence of this parameter. Using adjusted R2 as a guide, nonlinear crown width models adapted for local basal area (NLCWadj) improved predictions for 20 of 24 species over a lacking this component (NLCW). The ecological significance of the improvement shown for some species may be minor, but for others the difference was substantial (often 8 percent).