Forest dynamics and disturbance regimes in the Italian Apennines

Abstract

Forests of the Apennines are characterised by high canopy cover and high tree species diversity (being at the interface between two major climatic zones of Europe), and provide important ecosystem functions to millions of people. They exemplify cutting-edge themes such as forest ecology in warmer climates, consequences of heavy land use, and resilience at the trailing edge of the distribution of many European forest species (Silver fir, Norway spruce, Beech, Black pine, Birch).We introduce the setting under the geological and climatological point of view and review the literature on the interactions between these long-term drivers and the specific, structural, and genetic diversity of these forest communities (e.g., effects of glacial refugia or tectonic/volcanic activity), followed by a brief outline of what little is known about natural disturbance regimes and their range of variability. Anthropogenic disturbances (fire, grazing) and land use changes (abandonment of cropland and pasture) have been by far the main drivers of forest dynamics at least for the last two millennia, determining for examples overageing of coppices, treeline advances, forest encroachment on former agricultural land.We suggest considerations about the interplay between these land use changes and disturbance drivers (e.g. fuel continuity), summarize comparisons between managed and unmanaged forests (e.g., increase in tree size, deadwood, biodiversity indicators), and elaborate on current proposals for climate-adapted management, highlighting specific and genetic diversity as an important source of resilience and adaptive potential.