Forest dynamics and disturbance regimes in the Italian Apennines

Abstract

11Forests of the Apennines are characterised by high canopy cover and high tree species diversity (being at 12 the interface between two major climatic zones of Europe), and provide important ecosystem functions 13 to millions of people. They exemplify cutting-edge themes such as forest ecology in warmer climates, 14 consequences of heavy land use, and resilience at the trailing edge of the distribution of many European 15 forest species (Silver fir, Norway spruce, Beech, Black pine, Birch). 16We introduce the setting under the geological and climatological point of view and review the literature 17 on the interactions between these long-term drivers and the specific, structural, and genetic diversity of 18 these forest communities (e.g., effects of glacial refugia or tectonic/volcanic activity), followed by a 19brief outline of what little is known about natural disturbance regimes and their range of variability. 20Anthropogenic disturbances (fire, grazing) and land use changes (abandonment of cropland and pasture) 21 have been by far the main drivers of forest dynamics at least for the last two millennia, determining for 22 examples overageing of coppices, treeline advances, forest encroachment on former agricultural land. 23We suggest considerations about the interplay between these land use changes and disturbance drivers 24 (e.g. fuel continuity), summarise comparisons between managed and unmanaged forests (e.g., increase 25 in tree size, deadwood, biodiversity indicators), and elaborate on current proposals for climate-adapted 26

Exploring patterns of beta‐diversity to test the consistency of biogeographical boundaries: A case study across forest plant communities of Italy

“…This could be due to the fact that forests of these regions are mainly distributed along Apennines, a geophysical homogeneous structure that connects both northern and southern regions of the Italian peninsula, as well as the Adriatic and the Tyrrhenian sides. Our probabilistic sample of the Italian forests is consistent with a highly connected system where the virtual absence of dispersal barriers and the presence of a comparable past history (Vacchiano, Garbarino, Lingua, & Motta, ) determined a strong compositional overlap among the forest plant communities of these two biogeographical regions. Therefore, Apennines could represent a biogeographical transition zone (Morrone, ).…”

Where are Europe’s last primary forests?

“…Mediterranean forests show fundamentally different structural characteristics from temperate mesic forests, due to the high-drought stress Mediterranean forests experience during the summer and due to fire disturbance (Karavani et al, 2018). The role of wildfires in shaping the structure of Mediterranean primary forests is particularly complex as today most wildfires are humaninduced (Ganteaume et al, 2013;Vacchiano, Garbarino, Lingua, & Motta, 2017). These conditions may hinder the development of structural features typically associated with old-growth stages, such as deadwood or large trees (Burrascano et al, 2013;Kulakowski et al, 2017).…”

Effects of natural and anthropogenic drivers on land‐cover change and treeline dynamics in the Apennines (Italy)

“…The Apennine climate is a mountain variant of the Mediterranean type, with mean temperature ranging from 0 to 11°C in Jan and from 24 to 28°C in Jul; total annual precipitation varies between 600 and 4,500 mm, with frequent snowfall events above 1,000 m a.s.l. (Vacchiano et al, 2017). The montane zone (800-2,000 m a.s.l.)…”

“…Numerous studies on European treelines have concluded that recent tree establishment above upper treeline results primarily from reduced human pressure (Gehrig-Fasel, Guisan, & Zimmermann, 2007;Motta, Morales, & Nola, 2006;Treml, Senfeldr, Chuman, Ponocna, & Demkova, 2016) because of a progressive decline in the profitability of mountain agriculture (Gotsch et al, 2004;Leuch, 2005). In the Apennines, land abandonment occurred later and was related to property shifts and urbanization processes in the lowland, favouring the natural secondary succession (Bracchetti, Carotenuto, & Catorci, 2012;Caballero et al, 2009;Pelorosso, Leone, & Boccia, 2009;Torta, 2004;Vacchiano, Garbarino, Lingua, & Motta, 2017). Shifting agricultural economies have caused an increasing exodus from mountain and rural areas in general (Chauchard, Carcaillet, & Guibal, 2007;Didier, 2001;Motta & Garbarino, 2003), causing widespread spontaneous reforestation (Conti & Fagarazzi, 2005;Gellrich, Baur, Koch, & Zimmermann, 2007;MacDonald et al, 2000).…”