As the climate warms, plant species that prefer a colder environment are disappearing from the mountain ranges of Southern Europe. Since many of these species have small distribution areas, they are now threatened with extinction, according to two new studies from European researchers.
"These species have migrated upwards, but sooner or later the mountain reaches its summit," said researcher and biologist Ulf Molau at Sweden’s University of Gothenburg. "Many alpine plant species are disappearing from mountain ranges in Southern Europe, and for some of them - those that are only found in a single mountain range - the outlook is extremely bleak."
Over a period of 10 years, researchers around Europe have gathered samples from 13 different mountain regions.
Using digital technology and intensive on-site field work, they have been able to study a grid pattern of square meters, selected on different high mountain summits, from the treeline up to the highest peaks.
The digital photographs provide a detailed picture of which species have disappeared between 2001 and the present day.
"Every research square is digitally photographed so that we can find our way back to the exact same position after 10 years or more, with centimeter precision," said Professor Molau. "By rolling out an analysis network, small 10 x 10 cm squares can be re-mapped."
Today, the researchers are able to observe that species are migrating upwards and that the variety of species in Southern European mountain regions has declined during the 10 years in which samples have been taken.
"This finding confirms the hypothesis that a rise in temperatures drives Alpine flora to migrate upwards. As a result, rival species are threatened by competitors, which are migrating to higher altitudes. These changes pose a threat to high-mountain ecosystems in the long and medium term," the authors state.