ScienceDaily (Apr. 19, 2012) -- A pan-European study published in Science shows that mountain plants across the continent are moving to higher altitudes. This often results in raised species numbers on mountain tops, when colonizers from lower down start to dwell on the summits. This study, however, also shows that upward shifts can lead to a reduction in species richness. The paper is based on detailed surveys of 66 mountain summits distributed between the north of Europe and the southern Mediterranean Sea. An international research group, led by the Austrian Academy of Sciences and the University of Vienna, mapped all plant species at each site in 2001 and 2008 using the same standardized procedures.

The study was coordinated by Harald Pauli, Michael Gottfried, Stefan Dullinger and Georg Grabherr.

Increasing species numbers were only found on summits of northern and central Europe. By contrast, species numbers were stagnating or declining at nearly all sites in the Mediterranean region. Harald Pauli from the Global Observation Research Initiative in Alpine Environments (GLORIA) programme, which coordinated the study, said, "Our results showing a decline at the Mediterranean sites is worrying because these are the mountains with a very unique flora and a large proportion of their species occur only there and nowhere else on Earth