Gravbergsdalen, Naturreservat

The valley consists of a 600-meter-long fault line. At the bottom lies a small, untouched spruce forest. Above the fault line grows a mixed forest.

A Fault Created by Movements in the Earth’s Crust

The Gravberget fault was formed long ago during an eventful period in the Earth’s geological history. Violent movements in the Earth’s crust caused large faults to form in the bedrock. Over the millions of years since the fault in Gravberget formed, it has widened due to weathering and erosion. Today, the fault valley is at most 10 meters deep and 5–10 meters wide.

Old spruce trees nourished by gabbro

The nature reserve is home to an old coniferous forest of spruce and pine. The pines are around 200 years old. The trees are large and majestic, and the vegetation is somewhat richer than in the surrounding area because the bedrock consists of gabbro. This is a basic rock type that provides nutrients to the soil. The forest contains plenty of decayed, fallen tree trunks—logs—and standing dead trees—deadwood.

Teeming Life After Death

The decayed wood is valuable for the forest’s diversity of plants and animals. Between 6,000 and 7,000 of Sweden’s forest-dwelling species depend on dead wood at some point in their lives. Many of these wood-dwelling species are fungi. In the nature reserve, you can easily find common polypores such as the tufted polypore, the violet polypore, and the sticky polypore. A trained eye can also spot rarities like the woolly polypore and the cream polypore.