, 2013 and Pellissier et al., 2013). These processes have been exacerbated as a consequence of the abandonment of agricultural and pastoral activities (Piussi and Farrell, 2000, Chauchard et al., 2007 and Zimmermann et al., 2010) and changes in traditional fire uses (Borghesio, 2009, Ascoli and Bovio, 2010, Conedera and Krebs, 2010 and Pellissier Trichostatin A clinical trial et al., 2013), combined with intensified tourism pressure (Arndt et al., 2013). Many studies show how land-use abandonment and the following tree and shrub encroachment have negative consequences on biodiversity maintenance in the Alps, e.g., Laiolo et al. (2004), Fischer et al. (2008), Cocca et al. (2012), Dainese and Poldini (2012).

Under the second fire regime conditions, landscape opening favoured the creation of new habitats and niches with an increase in plant species richness (Carcaillet, 1998, Tinner et al., 1999, Colombaroli et al., 2010 and Berthel et al., 2012) and evenness, e.g., less dominant taxa (Colombaroli

et al., 2013). Such positive effects of fire on taxonomic and functional diversity are usually highest at intermediate fire disturbance level for both the plant (Delarze et al., 1992, Tinner et al., 2000, Beghin et al., 2010, Ascoli et al., 2013a and Vacchiano et al., 2014a) and invertebrate community (Moretti et al., 2004, Querner et al., 2010 and Wohlgemuth et al., 2010). In some cases fire favours the maintenance of habitats suitable for endangered Luminespib nmr Methane monooxygenase communities (Borghesio, 2009) or rare species (Moretti et al., 2006, Wohlgemuth et al., 2010 and Lonati et al., 2013). However, prolonged and frequent fire disturbance can lead to floristic impoverishment.

On the fire-prone southern slopes of the Alps the high frequency of anthropogenic ignitions during the second fire epoch (see also Fig. 2 and Fig. 3 for details) caused a strong decrease or even the local extinction at low altitudes of several forest taxa such as Abies alba, Tilia spp, Fraxinus excelsior and Ulmus spp. ( Tinner et al., 1999, Favilli et al., 2010 and Kaltenrieder et al., 2010) and animal communities, e.g., Blant et al. (2010). In recent times however, opening through fire results also in an increased susceptibility of the burnt ecosystems towards the colonization of invasive alien species ( Grund et al., 2005, Lonati et al., 2009 and Maringer et al., 2012) or animal communities, e.g., Lyet et al. (2009) and Blant et al. (2010). Similar to what is reported for the Mediterranean ( Arianoutsou and Vilà, 2012) or other fire prone ecosystems ( Franklin, 2010 and Monty et al., 2013), also in the Alpine environments fire may represent an unrequested spread channel for alien invasive species with pioneer character, what reinforce the selective pressure of fire in favour of disturbance adapted species of both native ( Delarze et al., 1992; Tinner et al., 2000 and Moser et al., 2010) and alien origin ( Lonati et al., 2009 and Maringer et al., 2012) ( Fig. 7).