climatic change (Tylianakis et al. 2008). However, one should also consider that
mountain landscapes have gone through marked climatic fluctuations even in recent
time (e.g., Little Ice Age), so fixed stability in the species interactions and
Fig. 1.6 Parnassius apollo (a) and Limenitis reducta (b) from Aigüestortes i Estany de Sant
Maurici National Park (Pyrenees). Parnassius apollo has experienced strong regressions in its
lower altitudinal limit in France and likely in many southern places of the Iberian Peninsula. The
regression is related to a shorter snow cover duration and thus thermal insulation of the immature
instars. On the contrary, the Mediterranean species L. reducta may be expanding its altitudinal
range in the mountains (C. Stefanescu, com. per.). Butterflies and other invertebrates provide early
evidence of nature’s response to climate change in the mountains. Although climate warming will
change the distribution of the biota across altitude in most of the mountains of the world, not all the
species will respond in the same way and at the same pace (Laiolo and Obeso 2017). They possess
different capacities to withstand changes and to migrate. Short living and motile organisms are
responding in a faster way, and we can expect a long period of continuous rearrangement of the
interactions among them. Nature reserve aims have to switch from a purely conservative strategy
towards a stewardship of the changes that may happen. Photography: Marta Avizanda, Archive of
the Aigüestortes i Estany de Sant Maurici National Park
20
J. Catalan et al.
mountain landscapes have gone through marked climatic fluctuations even in recent
time (e.g., Little Ice Age), so fixed stability in the species interactions and
Fig. 1.6 Parnassius apollo (a) and Limenitis reducta (b) from Aigüestortes i Estany de Sant
Maurici National Park (Pyrenees). Parnassius apollo has experienced strong regressions in its
lower altitudinal limit in France and likely in many southern places of the Iberian Peninsula. The
regression is related to a shorter snow cover duration and thus thermal insulation of the immature
instars. On the contrary, the Mediterranean species L. reducta may be expanding its altitudinal
range in the mountains (C. Stefanescu, com. per.). Butterflies and other invertebrates provide early
evidence of nature’s response to climate change in the mountains. Although climate warming will
change the distribution of the biota across altitude in most of the mountains of the world, not all the
species will respond in the same way and at the same pace (Laiolo and Obeso 2017). They possess
different capacities to withstand changes and to migrate. Short living and motile organisms are
responding in a faster way, and we can expect a long period of continuous rearrangement of the
interactions among them. Nature reserve aims have to switch from a purely conservative strategy
towards a stewardship of the changes that may happen. Photography: Marta Avizanda, Archive of
the Aigüestortes i Estany de Sant Maurici National Park
20
J. Catalan et al.