disturbances and pollution) that threaten natural systems, in concordance with the
desire of societies to preserve their collective memory of natural heritage. This
passive attitude to conservation is challenged by strategies focused on adaptive
conservation that take the insufficiency of our current knowledge as the starting
point for the development of more effective practices (Holling 1978; Armitage et al.
2008). Exposure reduction may obtain remarkable results at a local scale, particularly in the face of changes in land use, which represent a major threat to high
mountain ecosystems (Theurillat and Guisan 2001; Spehn et al. 2006), but it clearly
proves inefficient against exposure to agents that operate at global or regional
levels, such as pollution and climate change. The capacity of local managers to
reduce exposure to these agents is very limited. For instance, high mountain lakes
are particularly exposed to airborne chemical loadings (see Camarero 2017b), and
in this case reducing the sensitivity of these ecosystems involves the preservation of
biodiversity and food webs (Ventura et al. 2017).
High mountain areas are particularly exposed to climate change due to their
position at the extreme of regional climatic gradients. Accordingly, at the global
scale, vulnerability to the vegetation shifts associated with climate change is considered particularly high in alpine biomes (Gonzalez et al. 2010). Isolation and
habitat specialism contribute to this vulnerability (La Sorte and Jetz 2010). In
Europe, alpine and Mediterranean mountain environments are projected to decline
dramatically in comparison with other climatically defined environments (Metzger
et al. 2008). Thus, we expect a significant loss of habitat for many plant species
particularly as a result of decreased precipitation (Engler et al. 2011). This loss of
habitat may not be exclusively due to a decline in a species’ climatic suitability, but
rather to the improvement in conditions for species such as trees, which can modify
the habitat and competitively exclude current populations of high mountain specialists (Dirnböck et al. 2011). Nevertheless, at the species level, at least until now
in Europe, mountain areas seem to exhibit a substantial inertia in the face of
modifications to biodiversity caused by climate change (Theurillat and Guisan
2001). In fact, mountains may constitute a shelter for many species on account of
their topographic characteristics, which provide altitudinal corridors (Loarie et al.
2009). Furthermore, high mountains may become a refuge for species threatened by
global changes in their current distribution at lower altitudes (Sergio and Pedrini
2007), thereby emphasising the importance of preserving large-scale elevation
gradients (Moritz et al. 2008).
Given local managers’ inability to directly influence climatic trends, conservation trade-offs should focus on reducing sensitivity to climate change, in many cases
by acting on co-drivers that produce deleterious synergies in combination with
climate change (Hulme 2005; Mawdsley et al. 2009), or alternatively by enhancing
mechanisms of stabilisation and resilience (Lloret et al. 2012). Nowadays, this
strategy of reducing sensitivity to climate change has established a place on agendas
for conservation. This issue is becoming particularly relevant and challenging in
high mountain ecosystems, due to the harshness and distinctiveness of their habitats, but also due to the frequent involvement of small populations that have
experienced directional selection for generations. Specifically, management focused
46
F. Lloret
desire of societies to preserve their collective memory of natural heritage. This
passive attitude to conservation is challenged by strategies focused on adaptive
conservation that take the insufficiency of our current knowledge as the starting
point for the development of more effective practices (Holling 1978; Armitage et al.
2008). Exposure reduction may obtain remarkable results at a local scale, particularly in the face of changes in land use, which represent a major threat to high
mountain ecosystems (Theurillat and Guisan 2001; Spehn et al. 2006), but it clearly
proves inefficient against exposure to agents that operate at global or regional
levels, such as pollution and climate change. The capacity of local managers to
reduce exposure to these agents is very limited. For instance, high mountain lakes
are particularly exposed to airborne chemical loadings (see Camarero 2017b), and
in this case reducing the sensitivity of these ecosystems involves the preservation of
biodiversity and food webs (Ventura et al. 2017).
High mountain areas are particularly exposed to climate change due to their
position at the extreme of regional climatic gradients. Accordingly, at the global
scale, vulnerability to the vegetation shifts associated with climate change is considered particularly high in alpine biomes (Gonzalez et al. 2010). Isolation and
habitat specialism contribute to this vulnerability (La Sorte and Jetz 2010). In
Europe, alpine and Mediterranean mountain environments are projected to decline
dramatically in comparison with other climatically defined environments (Metzger
et al. 2008). Thus, we expect a significant loss of habitat for many plant species
particularly as a result of decreased precipitation (Engler et al. 2011). This loss of
habitat may not be exclusively due to a decline in a species’ climatic suitability, but
rather to the improvement in conditions for species such as trees, which can modify
the habitat and competitively exclude current populations of high mountain specialists (Dirnböck et al. 2011). Nevertheless, at the species level, at least until now
in Europe, mountain areas seem to exhibit a substantial inertia in the face of
modifications to biodiversity caused by climate change (Theurillat and Guisan
2001). In fact, mountains may constitute a shelter for many species on account of
their topographic characteristics, which provide altitudinal corridors (Loarie et al.
2009). Furthermore, high mountains may become a refuge for species threatened by
global changes in their current distribution at lower altitudes (Sergio and Pedrini
2007), thereby emphasising the importance of preserving large-scale elevation
gradients (Moritz et al. 2008).
Given local managers’ inability to directly influence climatic trends, conservation trade-offs should focus on reducing sensitivity to climate change, in many cases
by acting on co-drivers that produce deleterious synergies in combination with
climate change (Hulme 2005; Mawdsley et al. 2009), or alternatively by enhancing
mechanisms of stabilisation and resilience (Lloret et al. 2012). Nowadays, this
strategy of reducing sensitivity to climate change has established a place on agendas
for conservation. This issue is becoming particularly relevant and challenging in
high mountain ecosystems, due to the harshness and distinctiveness of their habitats, but also due to the frequent involvement of small populations that have
experienced directional selection for generations. Specifically, management focused
46
F. Lloret