Influence of light and competition on crown and shoot morphological parameters of Norway spruce and silver fir saplings

Abstract

The effects of a natural gradient of light and competition on crown, shoot and needle morphology of naturally regenerated Norway spruce (Picea abies) and silver fir (Abies alba) saplings, 0.8-0.2 m tall, were analyzed in a uneven-aged, managed stand in Comelico (eastern Italian Alps). The results indicate that: (i) both crown, shoot and needle morphology are strongly affected by light, but in the examined conditions (relative irradiance ranging from 2 to 32%) no significant effect of competition was observed, (ii) the ecological differences between Norway spruce and silver fir saplings cannot be mainly attributable to differences in crown morphological traits, and (iii) the apical dominance ratio (i.e., the length of the apical leader divided by the mean length of the lateral shoots at the last node) is a relatively good and simple indicator of the light conditions in which saplings are growing. These informations may be useful in order to promote and assure effectively natural regeneration. © INRA, EDP Sciences, 2005.