Chapter 12
Non-equilibrium in Alpine Plant
Assemblages: Shifts in Europe’s Summit
Floras
Christian Rixen and Sonja Wipf
Abstract Climate warming has been more pronounced in Arctic and alpine areas,
and changes in the mountain flora can be expected as the temperature envelope
moves upslope. On the one hand, alpine habitats will shrink due to upward
migration of species from lower areas, such as trees and tall plants. On the other
hand, extinctions of summit plants may be slowed down considerably by the high
diversity of microhabitats, the longevity of alpine plants and positive plant–plant
interactions in extreme environments. This review chapter attempts to document
and monitor vegetation changes on mountain summits. Vegetation surveys that
repeat century-old historical vegetation records show considerable upward migration and subsequent increases in species on summits. This trend apparently has
accelerated in recent decades. Detailed monitoring of the last decade in European
mountain ranges, however, shows that this vegetation change may be at the cost of
rare endemic species and alpine specialists in drier Mediterranean regions. This
chapter furthermore reviews other factors than temperature influencing alpine
vegetation, namely precipitation and snow, nutrients, atmospheric CO 2 concentrations and land use. A subsequent question is how threatened mountain flora is by
the ongoing environmental changes. Finally, this chapter discusses options for
conservation and land use in high-alpine areas.
Keywords Climate change Á Alpine plants Á Long-term monitoring Á Warming Á
Snow Á High mountain conservation
C. Rixen (&) Á S. Wipf
WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11,
CH-7260 Davos Dorf, Switzerland
e-mail: rixen@slf.ch
© The Author(s) 2017
J. Catalan et al. (eds.), High Mountain Conservation in a Changing World,
Advances in Global Change Research 62, DOI 10.1007/978-3-319-55982-7_12
285
Non-equilibrium in Alpine Plant
Assemblages: Shifts in Europe’s Summit
Floras
Christian Rixen and Sonja Wipf
Abstract Climate warming has been more pronounced in Arctic and alpine areas,
and changes in the mountain flora can be expected as the temperature envelope
moves upslope. On the one hand, alpine habitats will shrink due to upward
migration of species from lower areas, such as trees and tall plants. On the other
hand, extinctions of summit plants may be slowed down considerably by the high
diversity of microhabitats, the longevity of alpine plants and positive plant–plant
interactions in extreme environments. This review chapter attempts to document
and monitor vegetation changes on mountain summits. Vegetation surveys that
repeat century-old historical vegetation records show considerable upward migration and subsequent increases in species on summits. This trend apparently has
accelerated in recent decades. Detailed monitoring of the last decade in European
mountain ranges, however, shows that this vegetation change may be at the cost of
rare endemic species and alpine specialists in drier Mediterranean regions. This
chapter furthermore reviews other factors than temperature influencing alpine
vegetation, namely precipitation and snow, nutrients, atmospheric CO 2 concentrations and land use. A subsequent question is how threatened mountain flora is by
the ongoing environmental changes. Finally, this chapter discusses options for
conservation and land use in high-alpine areas.
Keywords Climate change Á Alpine plants Á Long-term monitoring Á Warming Á
Snow Á High mountain conservation
C. Rixen (&) Á S. Wipf
WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11,
CH-7260 Davos Dorf, Switzerland
e-mail: rixen@slf.ch
© The Author(s) 2017
J. Catalan et al. (eds.), High Mountain Conservation in a Changing World,
Advances in Global Change Research 62, DOI 10.1007/978-3-319-55982-7_12
285