Stensjön, Naturreservat

Stensjön nature reserve is part of a large, contiguous wilderness with almost no roads. Barn owls, capercaillie, three-toed woodpeckers and other large forest birds nest in the old coniferous forest. Rare lichens and fungi grow on dead, lying trees and on the branches and trunks of old trees.

Capercaillie and three-toed woodpecker

The forest around Stensjön is known for its capercaillie. The capercaillie is a distinctive coniferous forest bird that thrives in the sparse pine forests in the northern part of the area. In the pine forest there are small bogs and marshes with a high production of insects, where the capercaillie chicks can find food. The three-toed woodpecker is another of the area's characteristic species. On several trees in the reserve there are typical traces of the three-toed woodpecker, so-called drinking rings. Drinking rings are hack marks that run like bands around the tree trunks.

Traces of kites and forest fires

Large parts of the forests in the Bergslagen region were intensively managed during the heyday of mining.
The forest was needed for the production of coal. But in Stensjön the forest has escaped
thanks to the difficult terrain, with rocks, boulders and cliffs, which made forestry difficult. Some charcoal cutting has nevertheless taken place, and there are traces of both charcoal huts and charcoal kilns in the forest. Natural fires are also part of the history of Stensjön. There are clear traces of forest fires on several stumps in the reserve.

Unusual lichens

Northeast of the lake is an area of old spruce forest. The forest is sparse, patchy and blocky. The boulders are covered by dense mats of moss. Many trees are up to 150 years old and completely draped with various hanging lichens, such as twig lichen and violet-grey thorn lichen. The purple loosestrife is an unusual, northern species that requires sparse, untouched spruce forests with high and even humidity. Closer to the lake, the proportion of aspen, willow and rowan increases. There is also an exciting lichen flora on the deciduous trees, with unusual species such as aspen yellow lichen, tufted lichen and beard lichen. South of the lake there are large, 100-year-old aspens. Here the bedrock consists of nutrient-rich greenstone, which means that the trees are coarser and the spruce forest more herb-rich. Unusual wood-living fungi are found here, including the candelabra fungus, a rare species that grows on coarse, decaying aspen leaves.