| Quantification of the effects of residual forest structure on the understory light environment is needed to guide silvicultural strategies that facilitate regeneration. In this study I measured understory light using various methods in a dry, uneven-aged mixed conifer forest in British Columbia, Canada. These measurements were collected from an experiment established in 1994 where four residual basal area treatments (8m2/ha, 16m2/ha, 24m2/ha and uncut) effectively created a gradient of structure. Estimates of stand structure including density (N), basal area (G) and stand density index (SDI) explained 12 to 38% of the variability in understory light levels. Stand variables that heavily weighted the influence of larger trees on light attenuation were weak predictors of understory light. Incorporating variables describing the composition and size of trees in the overstory greatly increased the predictive power of the models. The abundance and growth of regeneration was strongly positively related to both light and understory vegetation. |
