water availability (Camarero et al. 2014). Vegetation on mountains with current
water limitation may be more resilient to extreme drought events (Herrero and
Zamora 2014), albeit that recurrent episodes may produce a progressive loss of
resilience (Lloret et al. 2004). Long-term palaeoecological evidence warns about
non-linear responses to water availability (Anderson 2012).
Most temperate mountain ranges are characterized by an altitudinal partition of
the slopes during spring into a snow-free belt and a white upper belt (Fig. 1.5). In
fact, there is a changing role of temperature and precipitation on snowpack. At
lower altitudes, temperature influence predominates and precipitation is a better
predictor of snowpack variability above certain altitudinal threshold (Moran-Tejeda
et al. 2013). As climate warms, the threshold will move upwards. Warming may
also affect heavy snowfall frequency differently with altitude, increasing the contrast between the upper snow belt and the lower altitudes with a shorter snow period
(Ignacio Lopez-Moreno et al. 2011).
Fig. 1.5 Landscape view of Val de Saboredo (Aran, Pyrenees). The typical spring division of the
high mountain into a white snow belt and a lower one where fields flourish will probably come
earlier and extend its duration with climate warming (Morán-Tejeda et al. 2017). This shift
increases potential risks (avalanches, floods) beyond the non-expert perception. Nature reserves
should be prepared for handling these increasing likely situations. Photography: Francesc Xavier
Bové Carbó, Archive of the Aigüestortes i Estany de Sant Maurici National Park
18
J. Catalan et al.
water limitation may be more resilient to extreme drought events (Herrero and
Zamora 2014), albeit that recurrent episodes may produce a progressive loss of
resilience (Lloret et al. 2004). Long-term palaeoecological evidence warns about
non-linear responses to water availability (Anderson 2012).
Most temperate mountain ranges are characterized by an altitudinal partition of
the slopes during spring into a snow-free belt and a white upper belt (Fig. 1.5). In
fact, there is a changing role of temperature and precipitation on snowpack. At
lower altitudes, temperature influence predominates and precipitation is a better
predictor of snowpack variability above certain altitudinal threshold (Moran-Tejeda
et al. 2013). As climate warms, the threshold will move upwards. Warming may
also affect heavy snowfall frequency differently with altitude, increasing the contrast between the upper snow belt and the lower altitudes with a shorter snow period
(Ignacio Lopez-Moreno et al. 2011).
Fig. 1.5 Landscape view of Val de Saboredo (Aran, Pyrenees). The typical spring division of the
high mountain into a white snow belt and a lower one where fields flourish will probably come
earlier and extend its duration with climate warming (Morán-Tejeda et al. 2017). This shift
increases potential risks (avalanches, floods) beyond the non-expert perception. Nature reserves
should be prepared for handling these increasing likely situations. Photography: Francesc Xavier
Bové Carbó, Archive of the Aigüestortes i Estany de Sant Maurici National Park
18
J. Catalan et al.