Ecophysiology and growth of advance red spruce and balsam fir regeneration after partial cutting in yellow birch–conifer stands
Daniel Dumais (1, 2) and Marcel Prévost (1)
1. Ministère des Ressources naturelles et de la Faune, Forêt Québec, Direction de la recherche forestière, 2700 rue Einstein,
Québec, QC G1P 3W8, Canada / 2. Corresponding author () / Received October 19, 2007; accepted March 19, 2008; published online June 2, 2008
Summary
We investigated ecophysiological and growth responses of short (0.4 to 1.3 m in height) advance regeneration of red spruce
(Picea rubens Sarg.) and balsam fir (Abies balsamea L.) six years after removal of 0, 40, 50, 60 and 100% of the overstory basal area (BA) in two yellow birch–conifer stands.
Partial cuts significantly increased stomatal conductance of red spruce only. Light-saturated photosynthesis (leaf-area basis)
of both species increased with BA removal, but unlike red spruce, specific leaf area (SLA) of balsam fir decreased with increased
cutting intensity. Partial cuts appreciably increased the concentration of N and Ca in red spruce and balsam fir foliage,
respectively, and resulted in decreased foliar concentrations of K in red spruce and Mg in balsam fir. The height and lateral
growth of both species increased with BA removal, although partial cuts were more beneficial to balsam fir. The data suggest
that short advance regeneration of red spruce and balsam fir can coexist under partial overstory conditions, but balsam fir
has physiological characteristics and a capacity for morphological adjustment (SLA) that places it at an advantage when in
competition with red spruce.
Keywords:
crown morphology, gas exchange, natural regeneration, nutrient status, partial overstory, photosynthetic acclimation, specific
leaf area, temperate mixed-wood forest, water stress.
