Stories from Gletsch
The glacier foreland
(by Erika Hiltbrunner)
- Story 13
In contrast to the glacier, the land that the glacier releases through its retreat is much less well studied. The glacier foreland was placed under protection together with the glacier in 1992 as an important floodplain landscape in Switzerland.
Land released by the ice and material deposited by the glacier is not sterile, but the soil is barely developed. The first pioneers are often various types of algae, lichens, mosses and plant species that can live on unstable ground. The soil develops with the help of plants and soil organisms. Depending on the altitude of the terrain, the first forest trees appear after 80 to 100 years, and after 100 to 150 years a sparse forest grows. These successions of vegetation stages are called succession. However, such succession can also be blocked or altered if the developing soil is too dry or too moist. Plant communities other than forest then establish themselves and a dynamic mosaic landscape is created. If the ice-free land is above the tree line, it takes around 300 years for the bare glacier foreland to develop into a closed alpine lawn.
What is very striking about the glacier forefield in Gletsch is that there are no trees in the oldest part of the glacier forefield (near Gletsch). Only in the rear, younger part of the glacier forefield are larches in particular to be found. Spruce trees are also rather rare in the glacier forefield. Valuable alluvial and scree communities are found near the glacial stream. For willow specialists (Salix sp.), the foreland is a veritable Eldorado. In recent decades, however, it has been observed that the green alder, due to its strong presence in the entire valley basin, is also overgrowing and displacing the special alluvial meadows with various willowherb species (Epilobium sp.) in the glacier foreland.
In the fens, where trees cannot grow due to waterlogging and herbaceous plants find it difficult to absorb nutrients, there are plant species that catch and digest small insects to meet their nitrogen requirements (Drosera and Pinguicula species). In total, over 350 higher plant species occur between the Rhone Glacier and Gletsch.
The vegetation sequences in the foreland of the Rhone Glacier are more complicated and do not adhere to the succession lines described in textbooks. This variety of different stages of development gives the Rhone Glacier foreland a special charm and is probably unique in the Alpine region.
It is well worth taking the time to observe nature here. There is much to discover in this special landscape.