Third fire generation anomalies also regard a potential shift of the lightning-caused fire regime season, generally concentrated in summer, to the spring season. During spring 2012, an extraordinary lightning fire ran over an area of 300 ha in the south-eastern Alps (“Tramonti

fire”, Friuli, 29th March–10th April). Similarly, recent large summer fires ignited by lightning have attracted public attention because of their extent, as for Pictilisib nmr example the “Monte Jovet Fire” in 2013 (Friuli), which lasted almost one month and spread over an area of 1000 ha, with crown fire phases and flames up to 50 m in height ( Table 1). The listed hot-spots and anomalies may indicate the shift towards a new generation of large natural fires as yet undocumented ( Conedera et al., 2006 and Pezzatti et al., 2009). The short historical overview on fire epochs and generations of large fires in the Alps makes it very clear how disturbance by fire has been and still is a prominent agent in shaping Alpine landscapes and habitats, producing a selective

pressure on species life-history traits and related distribution (Ravazzi et al., 2005), particularly since the last Ice Age (Tinner buy Everolimus et al., 2000, Vannière et al., 2011 and Colombaroli et al., 2013). In the subalpine belt, late glacial forest vegetation consisted of mixed stands of Pinus cembra, Betula spp., Pinus sylvestris, Pinus mugo and Larix decidua ( Vescovi et al., 2007). Periods when natural fire events were low in frequency (early Holocene) favoured why P. cembra dominance ( Gobet et al., 2003), while increases in fire activity (fire intervals of 200–300 yrs) favoured P. sylvestris, Picea abies, P. mugo, L. decidua, and Betula spp. ( Ali et al., 2005 and Stähli et al., 2006). However, during the second fire epoch the increased anthropogenic use of fire for land management resulted in a reduction of the tree component and an opening of the landscape. Some signs at landscape scale of the second fire epoch are still visible in several subalpine rangelands, where the timberline is artificially lowered and the combination

of pastoral fires and recurrent grazing maintain a savannah-like open forest structure (Conedera et al., 2007 and Conedera and Krebs, 2010). Relevant examples of cultural landscapes still maintained by periodic burning and grazing are the open wide-standing larch forests (Fig. 6, left) (Gobet et al., 2003, Ali et al., 2005, Schulze et al., 2007, Genries et al., 2009 and Garbarino et al., 2013), as well as the lowland Calluna vulgaris dominated heathlands ( Fig. 6, right) with sparse birches and oaks ( Borghesio, 2009, Ascoli and Bovio, 2010 and Vacchiano et al., 2014b). The third fire epoch has also been contributing to shape Alpine landscapes. Fire use bans and fire suppression have successfully reduced the overall area burnt in several Alpine regions, e.g., Pezzatti et al.