The flatland is characterised by a mosaic of low, marshy areas and higher islets of more solid ground. The forest is dominated by deciduous trees, mainly alder, downy birch and aspen, but spruce is also found on more solid ground. Most of the forest in the nature reserve has grown since Lake Väringen was lowered at the end of the 19th century, and is around 90 years old. The oldest trees are about 140 years old, and comprise pine, spruce and aspen that grow on hillocks that were islands before the lake level was lowered. Particularly valuable are the old giant aspens.
Deciduous trees dominate in the nature reserve because spruce cannot tolerate immersion in water for longer periods, which occurs in some years. During periods without flooding, the number of spruce trees increases. The last major flood took place in 1977, also killing birch trees, thereby giving wood-eating insects some golden years. It also benefitted the woodpeckers that ate the insects.
Birds, lichens, mosses and fungi
After the water level was lowered, and after a period of woodland pasture, Liaskogen has been almost completely undisturbed and unaffected by modern forestry. Consequently, there is a high proportion of deciduous trees and plenty of dead and dying trees. This benefits a large number of animal and plant species that require the habitats offered by the rare native forest. Many unusual lichens, mosses and fungi grow in the nature reserve, including tree lungwort, Nephroma laevigatum, aspen brittle-moss, Antitrichia curtipendula, as well as Phellinus ferrugineofuscus and Pycnoporellus fulgens. The area also has a rich birdlife, with species such as the red-breasted flycatcher and the wood warbler. You can also find several species of woodpecker, such as the lesser-spotted woodpecker, green woodpecker and black woodpecker. The white-backed woodpecker, almost extinct in Sweden, had one of its final outposts here before it became extinct in the county in the 1980s. The species disappeared because of the forestry industry’s effective removal of deciduous trees from the county’s forests. The osprey can be diving for fish in Lake Väringen.
The distance from the car park to the nature reserve is about 800 metres. There is a 2-km path in Liaskogen forest, and a picnic spot halfway round on the shore of Lake Väringen.
How to get there
There is a sign to the nature reserve on the road between Frövi and Ervalla, immediately west of Frövi.
In the nature reserve, you are not permitted to:
- remove branches, cut down or damage in any way living or dead trees and bushes
- pick mosses, lichens and wood-decay fungi
- drive motor vehicles or cycle
- light fires anywhere than in the designated area
- set up orienteering control points or mark trails with paper strips