Öjen has evolved in its natural state. Many fallen and decayed trees are an indication of a wild and undisturbed forest. Moreover, the fallen and decayed trees are very important for the life forms of the old-growth forest. Old trees are a home for different fungi, polypores, birds and small animals such as a flying squirrel.
A spruce is a dominant tree in Öjen's old-growth forest. Pines are planted or grow naturally in rocky areas. The amount of broadleaved trees is low compared to conifers. However, you can see a few old birches, aspens and goat willows. Here and there you can see handsome common aspen groves.
Öjen's large conifer forest is a good habitat for billberry. In addition to conifer forest, there are also small pine mires and spruce mires. The largest mire in the area is called Kålströmshagen which is a sedge-like mire.
In order to make the trees grow better, a part of Öjen's mires were canalized in 1991. The ditches were filled in the spring 1997 to restore the mires to their natural state. Mires are important habitats for many plant and animal species.
Open rocky areas can only be found at Öjen's highest point, Kompassberget. Otherwise the terrain consists of moraine and clay soil can be found in the hollows. Vaasa's own granite type, Vaasa granite, occurs in Öjen. Vaasa granite is grey, rough-grained and easily flaky and has distinctive white spots.
Rare Lichen and Luminous Moss
There are several moss and lichen species growing in Öjen old-growth forest, such as Collema subnigrescens and Schistostega pennata, which is also known as goblin's gold. Collema subnigrescens is classified as endangered species in Finland.
Goblin's gold grows on top of the roots of fallen trees. When it is dim, goblin's gold glows green and yellowy light. This mysterious light phenomenon is caused by small lens-like special cells on the surface of the moss. These cells reflect light extremely effectively.
Polypores
Various polypores thrive in a forest with lots of decayed trees, just like Öjen's forest. A proportion of polypores grow in living trees but the majority of polypores are decomposers that decay the dead tree substance. The organisms of an old-growth forest have very specific demands when it comes to habitats. For example, different polypores and fungi decompose trees in a specific order. Some polypores are particular about their host tree, some are more adaptable. Typical polypores for Öjen are Phellinus populicola (bracket fungus), Ganoderma lucidum (reishi mushroom), Phellinus chrysoloma, Phellinus ferrugineofuscus and Leptoporus mollis.