Light microclimate conditions that promote the establishment of Abies alba regeneration within Pollino National Park territory

Abstract

Studies carried out on the southern Apennine mountains have evidenced that silver fir (Abies alba Mill.), a species of great ecological interest, is undergoing a sharp contraction in its spatial distribution. This contraction is mainly due to the considerable anthropic pressure exerted in the past, even if negative effects of climate change may not be ruled out. The same fate befell silver fir in the Pollino National Park, where natural regeneration of the few remaining stands is struggling to establish itself, compared to more competitive species such as oak and beech. Before planning any intervention, it is crucial to investigate which micro-climatic conditions can promote the growth and development of silver fir regeneration. In such mixed plant communities, light microclimate of the understory is undoubtedly the main factor limiting the establishment of natural regeneration. Another preeminent factor is the water resource, which in the Mediterranean environment is becoming scarce especially during the growing season, as a consequence of climate change. Dendrochronological,
isotopic and photosynthetic investigations carried out on a representative regeneration survey have identified the most suitable microclimatic conditions which can help define the most appropriate management guidelines.