The research has been published in the prestigious scientific journal “Proceedings of The National Academy of Sciences of the USA” (PNAS). One of the authors Professor Martin T. Sykes is employed in the Department of Physical Geography and Ecosystems Analysis at Lund University. The researchers in the project have made their projections using seven different scenarios of future climates; the most extreme scenario suggests that global mean temperature increases by 3.6ºC by 2080. The scenarios project that the climate in the Mediterranean region becomes drier while it becomes a little wetter in Scandinavia.
— The study makes a number of different assumptions. But the modelling shows that two factors at the European scale most influence vegetation, the length of the growing period and how much water is available for plants during that period. More than half of the 1350 plant species we studied could be threatened – in many cases it is by range reduction and in other cases they may go extinct – summarized Professor Sykes.
— Above all it is vegetation in mountains that is most sensitive. The tree-line is likely to move upwards and many species that are nowadays only found at high elevations are likely to disappear. This trend was shown to be likely to occur in for example the Alps, the Spanish mountains and in the mountains of Scandinavia.
— Some species can move up mountain slopes as the temperature rises, but species that are only found in cold mountainous high elevation areas have no alternative strategy to survive a warming and nowhere to go.
In the forest areas the effect of climate change may not be as large, but in southern Sweden one can expect for example spruce to decline in some areas. Deciduous trees are likely to increase, along with broadleafed evergreen species.
The researchers’ models also show species decline in southern Europe. In Scandinavia when some species disappear or migrate northwards they may be replaced by species invading from south.
— It is a development that has already started, says Martin Sykes. Holly for example is established in Denmark, southwest Norway and in the very far south of Sweden, but other new research shows that it is spreading northwards along the Swedish east and west coasts.
Study published 7 June 2005. It is called – “Climate Change threats to plant diversity in Europe” with Wilfried Thuiller, Sandra Lavorel, Miguel B Araújo, Martin T. Sykes & I. Colin prentice as authors. The full article is available online from 26 May at http://www.pnas.org/misc/highlights