Sweden's mountains are growing greener. At the border between woods and bare mountain, trees that require warm temperatures, such as oak, elm, maple, and black alder, have become established for the first time in 8,000 years. This is shown in current studies led by Leif Kullman, professor of physical geography at Umeå University in Sweden.
Over the last century, the temperature has risen by more than one degree. The cooling trend over several thousand years is broken, and this has triggered changes in flora, fauna, and landscapes. In important respects, the present state is similar to what occurred directly after the latest ice age.
“Most noticeable, alongside the melting of glaciers, is an elevating of the timberline by 200 meters. Bare alpine areas are shrinking, and typical Nordic mountain birch forests are losing ground to spruce and pine, which are more competitive in a warmer and drier climate,” says Leif Kullman.