Post-fire restoration of beech stands in the Southern Alps by natural regeneration

Abstract

In the Southwestern Alps, the summer heat wave in 2003 was associated with unusually large wildfires in European beech forests, a tree species lacking from fire-specific traits and commonly considered as fire sensitive. Although knowledge regarding post-fire dynamics is a prerequisite for restoration measures, there is a considerable lack of studies on post-fire beech regeneration. We assessed the combined effect of fire, masting and salvage logging on natural beech regeneration after a mixed-severity fire in the summer of 2003 in the Italian Alps. The survey took place in 2010 in unmanaged stands and sites logged at different times after the fire. In unmanaged sites with steep and south-exposed terrain fire was severe, tree mortality was prompt and beech failed to resprout or regenerate from seeds. In moderate severity patches, mortality was delayed, permitting abundant beech seedling emergence as the effect of a masting in 2006. The progressive canopy opening provided intermediate light conditions which favoured sapling establishment. In managed sites, the time-lag between salvage logging and the masting affected beech regeneration. Sites logged in winter 2007 soon after the masting displayed higher beech regeneration in comparison to delayed cut or unmanaged stands. Post-fire pioneer species appeared to facilitate beech regeneration. Beech fire traits are discussed and ecologically-based silvicultural guidelines are provided for post-fire management in European beech stands.