Lichen - clever interaction
Lichen is a symbiotic association of an alga and a fungus, something which has proved a winning concept. The alga utilises energy from the sun, and the fungus protects the alga from drying out, storms and extreme cold.
Melanelia lichen shows how thick the snow is in winter. It grows almost anywhere in the mountain birch forest, but only above the snow cover.
Reindeer lichens form carpets on nutrient-poor ground throughout Sweden. Many call them white moss, but that is something completely different. Reindeer lichens have obtained their name since they are an important source of food for reindeer.
Many boulders and stones in Gränslandet are covered in concentric ring lichen, particularly in sparse forest and in the lower mountains. The lichen is sometimes called “the Russian empire”. It expands outwards and dies in the centre.
Bloodstain lichen grows close against boulders in windy locations.
What if map lichen could really show you the way! That would have been extremely practical, since it seems to grow on every rock in the mountains. The lichen is a flat, green patch that grows incredibly slowly. Large patches of map lichen can be more than a thousand years old.
Many lichens are so small that you need a magnifying glass to see them. One example is the yellow soot lichen. It’s a beautiful small lichen that grows on old hay barns and dead pines. This lichen is decreasing in Sweden, since dead pines and unpainted hay barns are becoming rarer.
Photo: Naturcentrum AB.
Not only reindeer...
… like eating lichens. So do cows. In the past, people gathered just as much lichen as hay before winter. Lichen was packed in stacks and when the snow arrived the frozen lumps were transported home. The animals were fed thawed lichen.