The mire landscape of Olvassuo is versatile. Those wandering on the mire will note that this large mire area is divided into a mosaic of various peatland types. Each peatland type has a species community of its own that requires a specific type of habitat.
There are plenty of rich fens here; elsewhere, most of them have been cleared and made into fields or drained for the needs of timber production. In late summer, these rich fens are spotted by the flowers of the rare yellow marsh saxifrage (Saxifraga hirculus) and the light-green tufts of the extremely endangered Lapland hamatocaulis moss (Hamatocaulis lapponicus) peak out of the open waters of the flarks.
Waders look for food at the flarks, and you may see a peregrine falcon (Falco peregrinus) racing across the mire at an insurmountable speed. In the more nutrient-poor areas, the mire looks like a grass field; there are sedges swaying in the wind and the monotony of the landscape is decreased by the wind-beaten birches growing here and there.
In the sections with thicker layers of peat, the surface of the mire has risen beyond the reach of spring floods, so the plants will not get any additional nutrients. In the barren raised bogs, the landscape is dominated by stunted pines that only grow a few metres tall despite their high age. Finally, the pines partly sink in the mire and become dead standing trees on the branches of which meadow pipits (Anthus pratensis) and yellow wagtails (Motacilla flava) sing.
On the margins and small bays of the mire labyrinths, there is only a thin peat layer covering the mineral soil. Large, grey and silent spruces thrive there. This is a spruce mire, where the dominant species of the field layer is the wood horsetail (Equisetum sylvaticum) and other vascular plants, creating a magic atmosphere in the shady forest. In autumn, the cloudberries growing between the tussocks are large and yellow.
Forest in the Middle of the Mire
Olvassuo does not only have mires. The highest mineral-soil islets have been saved from the paludifying effect of the peat moss, so there are natural-state ancient woods on these spots. Many beetles that require old-growth forests as their habitat and many threatened polypore species have found a favourable habitat in these forest islets.
History of Olvassuo
Olvassuo and Man
The history of the Olvassuo area is connected to the natural forms of livelihood. The area has always been an important hunting and berry picking area for people in nearby areas. The lush riverside and mire meadows provided fodder for cattle in winter, and reindeer grazed on the mires. The remains of the meadow saunas and hay barns in different parts of Olvassuo are signs of the meadow culture period. The old tar pits by the river and brook banks are reminders of the time when foreign exportation took its first significant steps in these remote areas.
The Olvassuo area also has mires and forests that man has changed before the protection of the area was started. Restoration aims at speeding up the process of getting these areas back to their natural state. Mire ditches have been blocked and planted forests have been burned in order to allow the development of a natural-state forest. Mires have been restored especially in the southern parts of the area, i.e., in the Olvassuo proper and Leväsuo. Forest has been restored by burning the Pystönkoskenkangas area located in the Olvassuo Strict Nature Reserve.
Ancient Relics Were Found at Olvassuo
Metsähallitus surveyed the prehistoric and historic cultural heritage of the area in the summer of 2006. In the past, the local people had the right to use the bounty of nature at Olvassuo (which is located at the border of Utajärvi, Puolanka and Pudasjärvi) and in the surrounding area. The area was inhabited in the Stone Age. Proof of this was found in the discovery of depressions made by dwellings that may be up to 9,000 years old and some quartz objects.
In the historic era, Olvassuo and its surroundings were an important hunting, meadow, tar burning and logging area. The remains of tar pits, meadow barns, meadow saunas and loggers' cabins as well as a few trapping pits are signs of these former livelihoods.
The eskers in the middle of the area provided excellent travelling routes, and there are still some old, decayed duckboards left on the mires.