Canadian Journal of Forest Research · 1995 · 62 citations · 0 references
Life SciencesPlant BiologyPlant SciencesPhotosynthesisPlant AnatomyPlant MorphologyForest GrowthGrowth MeasurementShoot GrowthTree FormTree RegenerationCrown Morphology AnalysisCrown Shape VariationHeight Growth ResponseLight Effects On GrowthLight Effects On Shoot GrowthLight Gradient EffectsPhotosynthetic Photon Flux DensityTree Crown Form
This study characterized the height growth and crown form of 14-year-old balsam fir regenerated naturally under a light gradient varying from 3 to 83% of photosynthetic photon flux density (PPFD). After 14 years, total height growth was correlated with percent PPFD (R 2 = 0.766; p < 0.001). From 3 to 25% of PPFD, balsam firs went from a suppressed stage with an umbrella type crown shape to a full grown stage with a cone type crown shape. This morphological change was caused by a greater increase in leader length compared to the mean nodal branches length. The number of nodal and internodal branches increased with PPFD. Balsam fir crown morphology showed a strong plasticity with a light gradient going from 3 to 83% of PPFD.